First invented early 2003. Enhanced 2010
How it Works|
The first step of this process is in collecting some available energy, such as the warmth of solar energy. I have a 'heat collection chamber' which has two 'air valves', one at each end. It is mostly glass or plastic, with a black floor inside to absorb the most solar energy. About 45% of the time, it is collecting solar energy, which slightly builds up air pressure inside due to the Ideal Gas Law and the extra heating due to the sun. Then, the EXIT air valve opens, which sends some of this slightly pressurized air through a large-diameter air duct, into the CUBE where it is used, for about another 45% of the time. Finally, the EXIT air valve closes and an ENTRANCE air valve opens, so for the final 10% of the time, fresh (cool) air is allowed to enter the chamber, to replace air which had been used and sent to the CUBE.
Another identical chamber also collects solar heat, but it is TIMED to be SUPPLYING slightly pressurized air during the opposite half of the cycle, so that the CUBE has a constant supply of slightly pressurized air coming to it. Three or more heat collection chambers could be made and used, if desired.
Finally, the slightly pressurized warm air goes into the LOWER chamber inside the CUBE. There is a 'piston' which separates the two sides of the CUBE's air chambers. The slightly higher air pressure which has been sent into the LOWER chamber PUSHES UP on that piston surface. The piston is large, nearly 4 feet square, and so there is about 2300 square inches of piston area being PUSHED UPWARD by that slightly pressurized air in the lower chamber. (The UPPER chamber is open to the atmosphere, so there is 14.7 PSI of natural air pressure pushing DOWN on the piston. The fact that the LOWER chamber is filled by SLIGHTLY pressurized air, at 15.2 PSI pressure, results in the entire piston being PUSHED UPWARD with a total force of 2300 * (15.2 - 14.7) or 1150 pounds UPWARD FORCE. The CUBE's piston is mounted to a long AXLE, which has a 400 pound steel weight out at each very end. Since the weights are the same, when the piston is centered, the CUBE is balanced. A few seconds later, after the pressure differential had pushed the piston two vertical feet upward. it is now extremely TOP HEAVY. We have added 800 pounds weight times 2 vertical feet upward, or 1600 foot-pounds of Potential Energy to it in the process of making it top heavy. The CUBE then ROTATES due to that top heaviness, which drives a pulley and fan belt and a car alternator, to make electricity in nice quantity.
You can entirely eliminate your dependence on the Electrical Power Grid! That would eliminate the need for anyone burning coal (fossil fuel) which is used to produce most of (51%) the electricity in the US. This simple device can use any of dozens of different energy sources, so you COULD use solar energy or wind energy or moving or flowing water, or even simpler and more readily available sources of energy such as slight differences in atmospheric air pressure!
I have invented something that SHOULD HAVE BEEN INVENTED 300 years ago! Isaac Newton knew enough to come up with this. So did Daniel Bernoulli. Blaise Pascal certainly did! It is too bad that they had not, as the Industrial Revolution might have then been very different, without the massive dependence on coal, then later petroleum, then uranium, and then natural gas. The planet might still have most of those natural resources now!
This is a side view of the standard-sized, four-foot square, rotating cube-shaped air cylinder of this device. The very large FIXED air ducts which need to slide connect to the (four) notches in the side are not installed in this photo to be able to see the cube. This photo also does not show the cube's top or bottom panels. The two lower notches receive a large amount of very slightly compressed warm air (from any of many sources, including sunlight) and that supply of compressed air is controlled due to the rotation position of the cube at any instant. The sliding shaft of the interior moving square piston (not shown here) is barely visible at the very top.
For the record, virtually all biological plants are only around 1% efficient in capturing this solar energy by photosynthesis, so the many experiments to try to grow algae or corn or other plants to produce electricity automatically starts off with a real disadvantage of having a 1% energy conversion ratio. The tolerably-priced Cadmium Sulfide solar panels are only around 7% efficient. You are about to learn about a method of capturing as much as 70% to 90% of the sun's energy!
You might see some humor in that billions of dollars are being spent to grow algae (1% efficient at collecting sunlight) and then trying to convert it into electricity. Many acres of greenhouses filled with algae and equipment will eventually be required to produce the electricity we are talking about from a 16-foot-square greenhouse-like collector described here. Ditto for huge fields of relatively expensive Cadmium Sulfide solar collector panels to do the same. And no one who spent $15,000 to buy a wind turbine has ever produced 15 kiloWatts of electricity, even for a minute! This is an ENTIRELY different approach! It is actually far better and far more efficient. Where other approaches tend to use a sequence of operations to make electricity, and each of those operations has dreadful efficiency (like processing biofuels to produce methane gas, compressing it for storage, then burning the methane to produce 3800°F heat to boil water, to then drive a steam turbine, to then drive an alternator to make electricity). There is no way to get good performance from such an approach because all the efficiency factors must be multiplied together which gives a rather low overall performance. Does that approach work to make electricity? Yes. But a disappointing amount of electricity. As noted, this is VERY different! It uses a source such as sunlight to SLIGHTLY warm a lot of air, which then slides a heavy weight upward to be able to fall downward due to gravity. We then just add a belt and pulley to directly spin one or more car alternators to make electricity. There are actually rather few ways to lose much energy with this approach, so the overall conversion efficiency into electricity is amazingly high!
Wind and wood and biomass and algae and fossil fuels are actually various stored versions of solar energy, but each had terrible efficiency factors in being created. Instead of accepting that 1% conversion efficiency of photosynthesis, this approach entirely bypasses that and simply uses the DIRECT heat of the Sun in warming air (or water), which tends to happen naturally and tends to happen with nearly 100% conversion efficiency. This description is meant to show you WHY you probably should not be holding your breath waiting for solar technologies or algae or biomass or such other technologies to develop. You ALREADY have available to you a DIRECT method of collecting the Sun's power at dozens of times more efficiently!
We are using that greenhouse-like structure simply to COLLECT solar heat and to briefly STORE a modest amount of the energy created, by producing a very slight increase in the air pressure inside of it (but in substantial quantities). We will then USE that slightly pressurized air to generate a LOT of electricity, by making a special device and sending that slightly pressurized air to it!
This capture process is quite efficient. IF you use standard glass in the greenhouse structure, the glass blocks a few percent of the sunlight, and our black floor inside also does not absorb quite 100% of the sunlight which hits it, but this is far higher in efficiency than any other approach to collect solar energy has ever been. Getting 92% of the incoming solar energy to stay as warm air is fairly easy to do, at least for the few seconds or the minute that we need to store it.
For the record, of the hundreds of known methods of collecting warmed or pressurized air, I felt that a greenhouse-like structure might be the cheapest to make and the simplest to assemble. I actually created TWO half-greenhouse-like structures, right next to each other, each 8 x 16, rather than one 16 x 16 structure. Why? You may have already figured it out! I have ONE of the two COLLECTING sunlight and building up pressure, as a CLOSED and SEALED chamber, while the OTHER one is connected to a large-diameter air-duct which allows the pressurized air in that chamber to be transferred to the actual main device to make the electricity. My air ducts are LARGE, resembling the cold air return main duct of a house central furnace, to be able to move enough air to drive the device and make enough electricity for my needs. I actually have ONE main duct connecting the heat-collection chambers with the main device, but I have a swinging damper where the duct approaches the two collection chambers. I attached a skinny metal rod to the side of the rotating main device, on an offset pivot, so the rod slides back and forth as the main unit rotates. This rod pulls and pushes the swinging damper to block first one of the chambers and then the other, alternately, and automatically timed to the rotation of the main device. What this results in is that ONE of the heat collecting chambers therefore always supplies the same side of the cylinder of the main device, and it is always pressurized (while the other collection chamber is then sealed shut and building pressure and while the other chamber in the main device's cylinder is opened to the atmosphere to release any pressure remaining in it.
I concede that this is somewhat wasteful of energy, which is against my basic principles. The idea of collecting the still somewhat warm and somewhat pressurized air from the opposite cylinder chamber, and in making more ducts to get that spent air to re-feed into the heat collection chambers seems to be an obvious future improvement. But for now, this thing makes SOOOOO much electricity that I guess I am somewhat spoiled! So for now, I lean toward simpler and cheaper construction than ultimate thermal performance. THAT will be enhanced later (or maybe by other people).
A central feature of our actual device is an application of Pascal's Law, that the pressure of any fluid (such as air or water) exists EQUALLY against every surface that the fluid is in contact with. Our device is essentially a VERY low-pressure version of a double-acting air cylinder.
In the case of air, a chamber filled with air normally applies normal atmospheric pressure of 14.7 pounds per square inch against every square inch of the surface of the chamber. Generally, there is also the exact same atmospheric pressure which exists against the opposite side of all the chamber walls, and so no net force exists. (Tornadoes change this balance by reducing the outdoor pressure by a couple PSI and buildings explode due to the normal air pressure which is still inside of the building.) We will describe here a SLIGHT increase in pressure, for example raising that normal 14.7 PSI atmospheric pressure up 0.5 PSI to 15.2 PSI. We then create a rather large chamber where all walls are fixed except for one, a very large area wall that will act as a piston, in our case, a SQUARE piston of 44" by 44" size or having an area of 1936 square inches. The result is that the movable wall has 14.7 PSI against its opposite wall and 15.2 PSI against the interior wall of the chamber, meaning that there is a NET pressure differential of 0.5 PSI. This differential pressure is very minimal, but it applies against each of the 1936 square inches of the piston's surface, which means that it applies a TOTAL FORCE of 968 pounds against the movable wall!
That enormous force is used to SLIDE a very heavy barbell (UPWARD) through the middle of the device, and the resulting unbalanced weights then cause the whole device to become top-heavy and to therefore rotate, with spectacular force and torque produced! You may have noticed that since we can apply an upward force of 968 pounds to the piston, we actually could have barbell weights up to around 450 pounds each (or 900 pounds total to lift). Performance is really amazing! We then USE that rotary power to make electricity!
Remember that there is around 10 horsepower of sunlight power and that we can collect around 9 horsepower of that? Now see how we will USE that power! IF our barbell-weight totals 900 pounds, and we are going to arrange to LIFT that 900 pounds by nearly FOUR VERTICAL FEET, in a period of about TWO SECONDS, that is a need of around 1800 foot-pounds per second. Since 550 foot-pounds per second is defined as ONE HORSEPOWER, our NEED is just over THREE HORSEPOWER to do this lifting at that rapid rate. The fact that we can constantly COLLECT around NINE HORSEPOWER of solar energy in bright sun, means that we will still be able to be collecting the NEEDED 3.3 horsepower even during partly cloudy skies or when the Sun happens to be fairly low in the sky! We have an abundance of available energy and power for what we actually need! We actually could even enhance performance more by either making the barbell slide further (longer stroke for the cylinder) or building a larger device where the piston has more surface area or increasing the 900 pounds of the barbell's weight, but those enhancements seem unnecessary, as even this relatively crude version can generate more than three horsepower worth of rotary power, which is around 2,500 Watts, far more than the (average) 1,000 Watts of electricity that most families normally use in America.
THIS is a tremendous force to be available from pressure differentials which might normally have seemed to be irrelevant! We are going to LIFT as much as 900 pounds of weight, as much as four feet vertically! It also turns out that this method has an efficiency of energy conversion that is far better than any current processes of creating mechanical energy (and then electricity from that).
The 3.3 horsepower we have just been describing is therefore MOSTLY converted into electricity, which provides around TWO KILOWATTS of produced electricity. The device can actually have far heavier barbell weights to produce far more electricity, but this brief description shows that even this simple and low-cost device can supply amazing amounts of electricity for any family, in this case from sunlight.
And the SUN is actually NOT even (directly) needed to drive this system! Since we ONLY need a temperature differential of around 17°F [or 10°C], we might even dig a pit and run the device on the temperature differential between DEEP SOIL (which is always around 52°F near Chicago) and even summer NIGHTTIME air which might be at 69°F. Oddly, in winter, it would work BETTER in that method, if the outdoor night air temperature was 0°F and the deep soil was still around 52°F (although a slight change then needs to be done to make it run "backwards"!)
All sorts of OTHER sources can be used, including flowing or falling water or modest windspeeds or even a variety of ways to use NATURAL DIFFERENCES in air pressure to drive it!
Then you need to know HOW MUCH POWER you NEED to raise YOUR barbell weight up the vertical distance that your device needs, (900 pounds times 4 feet here or) 3600 ft-lb. Then you need to know how long it takes gravity to make the top weight fall (which IS a fairly difficult calculation but for the size of device described here, is around 2 seconds. (We must RAISE the weights in that same interval of time to make it work best.) Therefore we NEED 3600 ft-lb per 2 seconds or 1800 ft-lb/sec, which is about 3.3 horsepower. THIS NUMBER MUST BE LESS THAN THE (9 HP of) power you can collect!
And then you need to know how efficient a belt and pulley drive is and how efficient a car alternator is. Additionally, you need to know that a SINGLE car alternator is generally limited to being able to produce around 60 amperes at 14 volts, or 0.84 kiloWatts, so you MIGHT need to consider using more than one such alternator.
Along those lines, you then need to decide HOW MANY car batteries you will want to have to STORE the electricity you will be producing. You PROBABLY want to USE most of your electricity in the evening, but it gets generated hours earlier. For this, you need to know that a standard car battery can reasonably store around 1 kilo-Watt-hour and still have a decently long life. So you are likely to want to have several batteries!
Finally, you need to know HOW MUCH AIR FLOW is needed, as it is quite significant (due to the very low pressure). Each time the piston moves (four feet here) to push the piston and weights up, you will need about 59 cubic feet of air (the entire volume of the cylinder). BOTH SIDES of the piston get pushed, back and forth, so this needs to be provided every two seconds, or 30 times per minute. This means that 1770 cubic feet of the slightly pressurized air is needed every minute. (Yes, the greenhouse-like structure WILL be cycling where it can draw in new air to replace the air you keep stealing from it!) This means that the AIR PATH must not be tiny but actually quite large in cross sectional area, comparable to or larger than the cold air return main duct in a house. THIS amount of Mass Air Flow provides the needed POWER to raise the weights and then make the electricity. IF you should happen to only provide 1/4 of that air supply, then the system still works, but then the piston only moves one foot per stroke instead of four feet, and it then only has enough power to make about 1/4 as much electricity. So on heavily overcast days, the system generally still works, but since it receives less sunlight, the piston moves in shorter strokes and it makes less electricity.
These simple calculations tell you what you can build for any desired amount of electricity! It is ALWAYS good to design it more powerful than you think you will actually need, for days that are only PARTLY sunny.
In 2003, during efforts to try to help save the city of Venice, Italy from disappearing under the Adriatic Sea, I did a small demonstration to prove that this basic concept works, at least the Pascal's Law part of it. A person has internal blood pressure which is roughly 1/8 of atmospheric pressure ( 95 mmHg / 760 mmHg) or nearly 2 PSI. That can therefore drive the many processes in the human body up to that pressure. So you can blow up balloons, spit water, urinate, etc.
I realized these facts and happened to have an old water bed. So I arranged a pattern of boards to distribute the weight of my car, and drove my Corvette up on top of the deflated waterbed. Only half the car fit on top of the waterbed, so I could only put around 2,000 pounds load on the bed. But the king-sized waterbed is around 80" by 60" in area. I realized that the 4800 square inches of the top of the waterbed surface area could raise the 2,000-pound load, more than six vertical inches, VERY EASILY! In fact, LESS THAN HALF A POUND PER SQUARE INCH differential would be sufficient. Since I knew that with my mouth, I could easily provide four times that much pressure, I knew it would be easy to squirt water by mouth into the waterbed to raise the car! However, I discovered that it quickly becomes extremely boring to be mouth squirting water into a hose for hours straight! So I eventually cheated a little and used a mechanical device to provide the necessary 1/2 PSI pressure. It took several hours to add the many gallons of water into the waterbed at such minimal pressure, and through a small hose, to raise the car, which is shown in the time lapse movie I made of the adventure.
Here are TWO AVI videos of that day. The first is a better quality movie, but it is about 5.7 Megabytes in size. The second is a grainier movie, but it downloads a lot faster as it is only 2.1 Megabytes in size. The two PHOTOS are different, before and after pictures!
here (5.7 MB)
or here (2.1 MB)
The point I was making that day was that Pascal's Law permits even a very minimal pressure differential to be able to create enormous net force to accomplish amazing results!
Regarding Venice in 2002, I was saying that even 1 PSI of differential (river) water pressure, pumped down underground over a hundred square miles could LIFT over 200 million tons that were above it. In other words, I was proposing to RAISE the entire city (at the rate of about an inch per month, very slowly, roughly five vertical feet in five years.). (Venice leaders showed no interest!) (My web-page on that idea is at Venice is Sinking into the Sea - Saving Venice. ) (After Hurricane Katrina, I also offered this idea of raising New Orleans up from their current negative seven feet altitude, but they were not interested either!)
Since I designed the basic device to operate on such VERY low pressure, it turns out that even the Sun is not (directly) needed! It is possible to dig a large PIT, where the air inside that greenhouse-like structure is actually several feet BELOW the ground surface. Near Chicago, the soil down there is always at about 52°F temperature. In that case, even at night, air can get HEATED by the deep soil or COOLED from nighttime air temperatures, and the airflow needs to be reversed, but it works just as well! It actually still IS Sun's energy, but that solar energy had gotten stored deep underground, so it IS technically still solar energy! As long as there is the 17°F temperature DIFFERENTIAL to produce the 0.5 PSI pressure differential to power the unit's large piston, it works perfectly well! And if the piston is made even larger, then even LESS pressure differential is needed!
The basic unit CAN be built to produce so much electricity that a single hour or so of good sunlight can produce enough electricity to fully charge 15 car batteries, to provide all the (15 kWh of) electricity that a modern American family uses in a 24-hour day.
(We tend to believe that making a $200 HG 3a device to heat the house is probably simpler and more desirable!)
One of MANY possible energy sources is solar energy. It would be very expensive to buy PV (photo-voltaic) panels of 256 square feet, and you would immediately already be down to only about 1.4 kiloWatts of electricity at the best, from something like $25,000 of purchased solar PV panels and the needed accessories. But here is a system where the overall efficiency is MUCH higher, on the order of TEN TIMES the efficiency of those PV panels, so we are looking at producing between 3 and 14 kiloWatts of electricity instead, and the cost to do this is mostly dependent on the cost and availability of the generic glass for the greenhouse walls, fairly cheap! Even one hour of good sun can realistically produce 3 to 14 kiloWatt-hours of electricity, most of which would then be stored in a bunch of car batteries (each of which can normally store around 1 KiloWatt-hour of electricity). Capturing and storing enough electricity for an entire day of NORMAL electrical usage by a whole family in a whole house, has become very practical!
Some more math confirmation: That size greenhouse-like structure contains around 2050 cubic feet, or about 150 pounds of air. Air has a Thermal Capacity of around 0.24 Btu/pound, so about 40 Btus are necessary to raise all that air by 1°F. With 25,600 Watt-hours or 80,000 Btus of Sun's energy being collected per hour, that is about 1300 Btus per minute. To warm our 150 pounds of air by the 17°F that we want, we therefore need about 680 Btu. Our greenhouse collects that much every 30 seconds or so. Even if we consumed ALL the pressurized air inside the chamber, and had to entirely RE-HEAT ALL THE AIR INSIDE THE GREENOUSE in just 30 seconds it would all again be pressurized! We actually do NOT use up all that 2,050 cubic feet, but only a small fraction of it (59 cubic feet for each stroke) for our device. So we have PLENTY of pressured air for our purposes!
Actually, there is a side benefit from this! The Sun does NOT stop just because your greenhouse has risen by 17°F! So, in actual operation, the air tends to rise far MORE than the desired 17°F, and it may rise even four times that much. What this then results in is warmed air that is at 2.0 PSI pressure rather than 0.5 PSI. (To design it to use this higher temperature might seem attractive, but the higher temperature tends to cause far greater heat losses from the [uninsulated] greenhouse walls, which reduces the overall efficiency of the system. I prefer to Design for a higher efficiency, where a side-benefit of providing higher pressure air to the piston/cylinder is nice!
You might have thought ahead and realized that an (airtight) BLACK hot air balloon, trapped in a rigid framework which fixes its size and volume, and is 18 feet in diameter also presents about the same area to the sun (254 square feet), but I consider that to not be durable enough for long-term electricity generation.
I personally don't even care if you do this or not but your wallet should have a lot more in it if you do! Additionally, if a lot of people would decide to save this money and become electrically and otherwise self-sufficient, the US might not need to import ANY petroleum or natural gas or uranium, which we do now in astounding quantities, and we might not need to mine or burn any coal, with lots of additional benefits for the environment and planet. It's entirely up to you!
I trust you noted above that by intercepting 10 horsepower of sunlight, and collecting 9 horsepower of that, even if you should build this device ineffectively, it will likely STILL provide at least 2 horsepower of needed power used to drive the device, to supply you with more than a kiloWatt of electricity, which is quite a bit. So even if you should really mess up the construction of the components, it STILL should supply all the electricity your family should ever need! So this all does NOT require a brain surgeon or an expert builder to create a very useful device! However, it is REALLY important to MAKE IT STRONG so that IT IS SAFE for anyone or any pets to be near. It DOES have rather heavy weights moving around at faster than walking speeds, and it would be bad if anything should break! Got it?
In fact, I ENCOURAGE everyone to START OUT with far less than 900 pounds! In fact, I encourage beginning with FIVE-pound weights on both sides (or ten pounds total). AND of using restrictors to keep the piston to only travel a total of FOUR INCHES (instead of four feet). In this configuration, it will likely only produce a few Watts of electricity (about one one-thousandth of what it is capable of producing). It also only needs an amazingly tiny pressure differential, even far less than the 0.5 PSI usually described here! But it only then uses 5 cubic feet of warm air during each stroke, AND there is no danger of your having built something poorly where a rapidly moving 500-pound weight might come loose and hurt someone! You can then EASILY add additional weights and or increase the stroke of the piston, to generate about any amount of electricity you are likely to ever want!
The idea of building a later second unit might also seem attractive, to be constantly charging a group of car batteries to power an electric car, to eliminate even THOSE expenses and imports.
Several different versions of this device and system can produce amazing amounts of electricity, easily enough for an entire American house. Entire descriptions and instructions are provided below for a unit which was designed to produce an easy 15 kiloWatt-hours of electricity every day (with some configurations, even in just one hour of really bright sun!), which is more than most American families use up. It can be built requiring only around $150 of standard building materials to build, along with two or three hours of simple work in assembling it. You MIGHT even be able to improvise regarding finding glass or a surplus weather balloon to collect the sunlight, to reduce the overall cost even more.
The concept and the devices are also scalable, so much larger devices may be similarly created. There seems a valid chance that extremely large versions of it might be made to replace current fossil-fuel-fired and nuclear-powered electric power plants with systems which can use solar energy, flowing water or falling water, or any of dozens of sources of low-grade heat to produce very large quantities of electricity.
This system is based on a FLUID which is under rather low pressure. That fluid can be any of many liquids or gases. The discussion here will only consider and discuss either air or water, with the discussion about the primary unit being one that uses normal air. It turns out that certain principles of refrigeration could also be used, where a SEALED system of a refrigerant could be contained. The premise there is that the refrigerant changes state from liquid to gas, where a more compact form of energy storage is then possible, where all the needed power to push the weights upward is provided. We see that approach as unnecessary here, and will not comment on that modification any further here.
A piston and chamber for a water-based system can be made, and is much smaller in size, but that adds in some leakage issues which we can ignore in the very low pressure air-based system described here.
Complete construction instructions will be presented below, for the air-based system.
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But it can be useful here to present the general idea they TRIED to use, because a much better application of that concept is the basis for this system and device. A bicycle is lying in your driveway. You STAND IT UP, which requires you to EXERT WORK (to raise the weight of the bicycle against the force of gravity). Then you let the bike fall over (DUE to that force of gravity) but now you would hook some string or rope or pulley or lever to try to make the falling bike "turn something" or "move something", in other words, the FALLING BIKE would do USEFUL WORK in the process of that falling. Then you stand the bike up again and let it fall over, over and over and over.
The REALITY is that there is something called the Conservation of Energy that people like Helmholtz learned about hundreds of years ago. And NO process is "perfectly efficient" due to things like air friction and crash noise sound production and other things. So the REALITY of what I just described ALWAYS requires you to have to exert MORE work in standing the bike up than it could ever possibly release as useful work in falling over.
Those people who dreamed of inventing perpetual motion and getting instantly rich and famous, never knew that or a few other details of science that make their dreams absolutely impossible.
But it DOES turn out that if you got rid of all the air around the bike or made it fall over slowly, you could minimize air friction. And if you put a cushion on the ground where it would land, you could minimize the amount of crash sound that would get created. THESE are important variations, and if they were done really carefully, they could make it NEARLY efficient, that is, the amount of work you had to do each time you picked the bike up might only be a tiny bit more than the amount of energy that might be recaptured as it fell back over. NOT perfect efficiency of energy conversion, but fairly close. We WILL refer to this shortly!
I am going to use several simple drawings to present some basic concepts now. Imagine the first drawing below to be a really strong weightlifter's barbell, where the shaft happens to pass THROUGH a hollow tube. Ignore that tube for the moment. The two large rectangles at both sides represent the heavy weights, 50 pounds at each end of the 100-pound barbell. We are going to say that the barbell is 4 feet long for the purpose of this discussion. Ignore the little rectangles and the rectangle in the middle of the hollow tube for now!
You are now going to copy the bike example by standing the barbell upright. It will now look like the drawing below. What did you have to do to accomplish this? The ONE weight did not get lifted at all but the OTHER one had to get lifted FOUR FEET UP. In other words, you did WORK that was equal to 50 pounds times 4 feet or 200 foot-pounds in order to do this.
Now that it is standing up, it is no more stable than the bike was, and it WILL quickly fall over. Again, the weight that was at the bottom would not really move much, but the one at the top has to fall four feet before hitting the floor! IF your desire was to create big dents in your hardwood floor, then you have found a way to do it! The upper fifty-pound weight will build up some decent speed as it falls that four vertical feet, and you will essentially have a really big sledgehammer!
OF the 200 foot-pounds of work that you added to the barbell by standing it up, the Conservation of Energy tells us that ALL that energy (or Work) has to still be in it, except for a tiny amount that gets used up by moving air out of its way (which can give up energy by both slightly warming the air due to friction and by making a quiet whistling sound as the weight goes past air). So, regarding having a really effective sledgehammer, that is certainly true, as well over 199 foot-pounds of that energy is otherwise still in it. For an instant BEFORE it hits the floor, nearly all that 199 foot-pounds has been CONVERTED into what is called Kinetic Energy, that is, energy of motion, which is the energy that the falling weight now contains which is in this different form.
And a moment later, the weight is no longer falling due to having hit the floor, so the Kinetic Energy has been converted into some other forms, specifically SOUND energy of the crash and INTERNAL DISTORTION ENERGY of the floor itself.
What seemed to be a very simple action, has actually involved a fair amount of science, where the energy got converted several times all in only a couple seconds!
But you COULD again stand it up and let it fall again, but I trust that you are smarter than that! However there ARE giant machines that do essentially that, called piledrivers. They usually have a big diesel engine which turns a very large hydraulic pump to LIFT a weight of several tons straight up and then releases it so that gravity can make the big weight build up some speed and smash into the ground under it. This drives the soil downward and out of the way, and in half an hour, a piledriver can install a foundation post for a highway bridge (which is probably where you saw it and heard it work!)
The important part for us is that the AMOUNT of that 200 foot-pounds that you put into the barbell by standing it up is NEARLY ALL STILL AVAILABLE. This is a VERY EFFICIENT process, fairly close to 100% efficient. That is relatively unusual in machinery or equipment. In case you are curious, your car is probably around 21% efficient at converting the energy in gasoline into actual movement of your vehicle. A giant electrical powerplant is generally about 32% efficient at converting the chemical energy in the coal into electricity which they then send to you (many miles away). And YOU are only around 20% efficient at converting the chemical energy in the food you digest into becoming useful work!
We are going to say that the cylinder is three feet long, for this part of the discussion.
BEFORE, we had the barbell forever laying on the floor or standing up on the floor, always in contact with the floor. But NOW we have that cylinder SUPPORTED by an AXLE, so the barbell is now ALWAYS actually HANGING and not EVER sitting on the floor. Only the center of that cylinder is now supported at all, by a (horizontal) axle which is supported on sturdy bearings (much like the wheel bearings on your car). We have added another object to the barbell, which is a big flat DISK mounted to the exact center of it, and where that disk is TRAPPED inside the cylinder.
Now we see the seeming complication I just mentioned! With nothing to SUPPORT the heavy barbell, it SLIDES THROUGH the cylinder to move as far down as it could possibly move. That is, it slides DOWNWARD until the upper weight of the barbell runs into the outer end of the cylinder. This next drawing shows what has happened (because of gravity!)
Fortunately, you have planned the height of the supporting axle to be high enough where the sliding and rotating bottom barbell weight still does not ever hit the floor!
But you have a situation now where the barbell has sunk even farther than we had before, meaning we will need to apply even MORE work to it to raise it back up to where we want it to return to.
We now have this set up so that IF you can just figure out how to get PRESSURIZED AIR INSIDE THE CYLINDER, but only inside the LOWER half of the cylinder, then we could use that PRESSURE to push up or lift up both that piston and the connected entire barbell, vertically upward.
NOW we have gotten to the importance of the two small rectangles (which are HOLES through the side wall of the cylinder) and the larger rectangle (which is actually a [double-acting] PISTON INSIDE the cylinder.)
NOTE: The small rectangles are rather small in these drawings, to not distract from the main concepts being presented. These are drawn for a WATER-based system, where the water passageways might be quite a bit smaller than the size of the necessary air-ducts and passageways which are needed for an air-based system. Also, these drawings are presenting a fairly small version of this system, which could only generate a few hundred watts. Using numbers (again???) if five gallons of water falls one vertical foot to enter the chamber, that DOES produce the 0.5 PSI of pressure, and it is also about 40 pounds of water falling one foot every two seconds, or about 20 ft-lb/sec, which is about 1/28 of a horsepower or about 30 Watts of power. Fine, but smaller than what we want or need! (IF the water fell FIVE feet instead of the one foot necessary to produce the pressure, we would then have about 150 Watts of available power, nearly all of which can be converted into electricity).
NOW we have something important!
Look at the drawing just above and now consider the two small rectangles. We will now OPEN the small rectangle at the top, which would RELEASE any fluid pressure which remains in the UPPER CHAMBER inside the cylinder. At the same time we will also open the rectangle at the bottom BUT we connect that one to a SUPPLY OF FLUID AT 0.5 POUNDS PER SQUARE INCH PRESSURE. (YOUR blood pressure is much more than that and you produce more pressure than that in blowing up a balloon, so this is a MINIMAL air pressure that we are supplying.)
Now consider the PISTON inside the cylinder, which we make with a BIG DIAMETER, such that its surface area (on either side) is 250 square inches area. So what happens now? We FILL the lower chamber with fluid (either air or water) that has our slight (0.5 PSI) pressure. We have plenty of air or water available at that very minimal pressure! Once we have sent enough fluid into that lower chamber, we will have 0.5 POUNDS PER SQUARE INCH fluid filling that entire (lower) chamber. A basic law of any Fluid (Pascal's Law) is that EVERY square inch of EVERY SURFACE inside any tank or chamber of fluid has the SAME pressure applied to it. Now get back to that piston which has 250 square inches of surface area on the under side of it, each of which is being pushed with 0.5 PSI of air pressure. The total effect of this is that the piston gets pushed UPWARD with 250 * 0.5 or 125 (vertical) pounds of total force. The entire barbell only weighs 100 pounds and the piston maybe another two pounds. So what happens now? Right! There is NO (net) pressure on the upper surface of the piston (because we opened the upper fluid release hole to let any pressure out) and we are now pushing upward with 125 pounds of upward force. The piston and barbell SLIDE UPWARD, all the way up as far as it can go.
That minimal air (or water) pressure (in fairly large quantity), when applied over the large area of the piston, therefore EASILY pushes the entire barbell upward, around three vertical feet. In other words, we have added 100 pounds * 3 vertical feet or 300 foot-pounds of work or energy to the barbell. YOU had done well with your muscles in adding 200 foot-pounds in standing the barbell up but now we have given the barbell even more energy. Remember, that energy cannot disappear, and can only be converted into some other form of energy!
We have now converted solar or wind or water or other energy sources, first into very low pressure fluid pressure, and now into POTENTIAL ENERGY of the raised and now top-heavy barbell. We then LET it fall which again converts the energy, now into rotary power of this device turning due to the effects of gravity. But we have now managed to get this very heavy barbell to ROTATE (continuously), all by supplying amazingly low pressure air or water, to raise it as necessary, which was obtained from any of a variety of energy source!
Only one more step is required, that of adding a belt and pulleys or a gearing system for this now (slowly) rotating barbell to drive an alternator (which needs far faster spin rates to perform well) which then converts such rotary motion directly into (DC) electricity, which can then be stored in car batteries.
This all results in extremely efficient energy conversion from a variety of sources, eventually into either mechanical power or electrical power. No current methods of making electricity are remotely as efficient!
Assume for the moment that we can provide a good supply of AIR which is just 1/2 PSI higher pressure than the ambient air in the room. Our PISTON is square, 44 by 44 inches so it has a surface area of 1936 square inches on each side inside the cylinder. For the record, air which is only at 0.5 PSI pressure does NOT move very fast, and in fact, it can be barely even noticeable! We will now arrange to provide that 0.5 PSI air supply INTO the one side of the cylinder chamber (the lower side), which will apply against every square inch of the inside surfaces of the LOWER chamber inside the cylinder. We multiply 0.5 * 1936 to find that the total pressure upward against the bottom side of the piston is 968 pounds along the direction of the sliding shaft. When the device is oriented vertically (maximum load), we can see that slightly over 900 pounds of weight needs to be supported by that piston, and the fact that we constantly and forever have the available 968 pounds of force easily provides that. The result is that the piston and sliding shaft WILL slide upward as a direct result of that very minimal air pressure (because there is such a large surface area of the piston involved).
Since we have already OPENED the release valve for the UPPER chamber, there is no pressure loading holding the piston down, and air from the upper chamber is simply released out to the room.
Since the available 968 pounds of force will easily lift the 900 pounds of the weights, the upward motion rate of the piston and sliding shaft and weights is primarily determined by the size of the airpath we provide for the supplying 0.5 PSI air. There are also considerations regarding momentum and acceleration of the heavy weights, which are simple physics problems, but it turns out that the (very large) airpath can be designed to have an appropriate airflow rate to match the other characteristics of the device. For the moment we will not specify the time it will take for the piston to move the four vertical feet to get to the top limit of its motion, but we will be able to determine this shortly, to properly match the airflow needed to provide the pressure and motion.
Once we have the weights up to their highest location, we have a situation resembling the unstable bicycle or the vertical-standing barbell.
We CAN see that we needed to apply 3600 foot-pounds of work to raise the two 450-pound weights vertically upward by 4 feet, that is 2 * 450 * 4 or the 3600 ft-pounds USED.
We STARTED with the weights sitting at their very lowest points, that is, the top one at 2.5 feet above the axle (the piston was then at -2.0 feet with the weight 4.5 feet above that, or +2.5 feet position), while the bottom weight is at -6.5 feet below the axle (again, the piston was then at -2.0 feet with that weight 4.5 feet below that, or -6.5 feet position.) If we use the axle as the origin of a location system, we can say that we then had +1125 and -2925 foot-pounds of potential energy or a net of -1800 foot-pounds of potential energy at that moment.
Now that we have applied the pressurized air and moved the sliding shaft vertically upward, we now have a situation is very top-heavy. Similar to the analysis we just did, we now have one 450-pound weight which is now SIX AND A HALF FEET ABOVE the axle (two feet INSIDE the cylinder and then four and a half more feet of the exposed sliding shaft above that), while the other 450-pound weight is TWO AND A HALF FEET BELOW the axle (now mostly inside the cylinder since the bottom weight is now nearly pressed against the surface of the bottom end of the cylinder). This is then therefore -1125 and +2925 foot-pounds of potential energy, respectively. Describing this as POTENTIAL ENERGY, and again considering the axle as an origin, we now have a net of +1800 foot-pounds.
We have therefore ADDED (+1800 ft-lb -(-1800 ft-lb)) or 3600 ft-lb of new POTENTIAL ENERGY to the now very top-heavy device, which fully accounts for the 3600 ft-lb of work that we provided to it as a lot of slightly compressed air.
Gravity now causes that POTENTIAL ENERGY to become converted into the KINETIC ENERGY of motion of the rotating device. We CAN now estimate how FAST the device will do half of a rotation. To do this accurately requires Calculus, so we will approximate the result here. Let's first consider the falling from vertical to horizontal, which is ONE-FOURTH of a full rotation. IF a weight fell STRAIGHT DOWN, without any restrictions, we know from Newton's Laws that an object in the Earth's gravitational field falls so that D = 0.5 * g * t2, the standard formula. We know that D is 6 feet for (the vertical motion of the upper weight from vertical top to horizontal) our device and g is 32 ft/sec2. We can easily calculate that t would have to be 0.612 second (so that 6 = 0.5 * 32 * 0.375).
A FULL revolution of the device might then seem to need around 2.5 seconds, or 24 rpm. Unfortunately, that is not quite true! The weight does NOT fall directly straight down, but it falls along the arc of a circle. This causes two fairly simple modifications of that calculation, each of which adds a factor of the SINE of the angle which the sliding shaft happens to be at, at each instant. A bit of Calculus is then needed to Integrate that effect over the entire one-fourth revolution which results in this device rotating around 19 rpm if NO LOAD is applied to it. If some of the available energy is drawn off to produce electricity, then it would rotate slower, again calculable with Calculus. Given realistic loading of the alternator, it is realistic to expect this device to rotate around 15 rpm in actual normal operation.
We can now do some further calculations. In an entire revolution, we need to raise the weights TWICE, in other words, we must add 7200 ft-lb of energy, 15 times every minute. That is around 108,000 ft-lb/minute. One horsepower happens to be 33,000 ft-lb/minute, so this is therefore around 3.3 horsepower of mechanical power. A horsepower is also equal to 746 Watts, so we are talking about 2500 Watts of mechanical power.
A car alternator has a usual overall efficiency where it can produce around 840 Watts of electricity from this, as a maximum of 60 amperes at 14 volts of DC electricity, directly compatible with standard car batteries, and within the range which used car alternators from a junkyard can produce.
We would clearly need THREE car alternators to be able to USE the 2500 Watts of power available in this configuration. We COULD use weights that were less than the 450 pounds each described here, and if so, the performance of the system is proportionally reduced. We could also choose to reduce the stroke of the piston, in order to use less of our compressed air, but that again would reduce performance proportionately.
This amount is VERTICAL (gravity), but the device requires the weight to move at an angle outward (at this location) which again has a factor of the sine of the angle. Therefore the actual ROTARY TORQUE produced at this instant is about 900 foot-pounds.
|UP ( 0º )||0 ft-lbs|
|UP ( 45º )||900 ft-lbs|
|UP ( 90º )||1800 ft-lbs|
|UP ( 136º )||900 ft-lbs|
|UP ( 180º )||0 ft-lbs|
|AVERAGE TORQUE||is around 900 ft-lbs|
If we provide sufficient air which is slightly pressurized, we now see that we produce an average of around 900 ft-lb of torque continuously, which is an immense amount, greater even than what high performance cars can produce for a few seconds! This device creates that constantly and continuously!
The weights follow a curved path, but they must still always follow the Conservation of Energy. Our air pressure RAISES the 900 pounds of weight a vertical distance of four feet (3600 ft-lbs), twice during each of about 15 revolutions per minute, or 30 times per minute, in other words, our energy source ADDED 3600 * 30 or 108,000 ft-lb / minute.
We noted above that is about 2500 Watts of mechanical energy being produced by the rotating cube. We also noted that a standard used car alternator from a junkyard could take that and produce a consistent 840 Watts of electricity, continuously, around 20 kWh each day.
We can also note that we used incredibly low pressure supply air to do this! If we just DOUBLED the air pressure up to 1.0 PSI, still extremely minimal, and if we built it strong enough to withstand stronger forces, the piston now could raise 1800 pounds of weight! All the logic presented above is still true, except that now we would be raising DOUBLE the weight to become potential energy, which means that two times the mechanical energy of rotation would be created by the cube. You would likely need to use a LOT of car alternators, but you could then produce nearly 5,000 Watts continuously, or around 120 kWh every day, FAR MORE than any normal family needs. However, there could be some danger in having such really heavy weights moving around in a home made structure! I just don't want something to break where a very heavy weight might come loose and hurt someone! So even though the DEVICE should be able to perform to even higher standards, the question might be whether you can build things which can handle all that weight!
|Main Structure Frame||2||pieces of 2"x10" 8-foot framing lumber.||$7.64 * 2 = $15.28|
|Main Structure Lag Screws||16||3/8"x6" standard lag screws.||$13.18|
|Washers||16||standard fender washers.||$3.92|
|Cast-Iron Floor Flanges||4||2"||$51.12|
|PL 400 Adhesive||1 tube||foam adhesive (like PL400).||$3.99|
|Axle Half-Shafts||2||2" iron pipe, 12" long||$7.24|
|Cube Walls||3 sheets||1" thick blue (underground) foam insulation, 4'x8' sheets||$31.98|
|Plywood Sheet||1||3/4" by 4'x8' type A-D exterior plywood||$18.48|
|Automotive Main Bearings||4||from a junk V-8 engine||$0.00|
|Used GM car alternator||1 or 2||from a junk car||$0.00|
This should total around $150 of materials.
If you are really sure about your source of energy (discussed below), maybe only ONE car battery may be needed, since the device can CONSTANTLY and CONTINUOUSLY make that 600 Watts during every minute of every day or night. However, when you decide to make toast, or blow-dry your hair, you need around 1500 Watts to run the toaster or blow-drier for that half-minute, so some amount of electricity storage gives more flexibility. You would NOT be able to operate the toaster for every minute of every day with this configuration, but you probably only need to use devices which are electricity-intensive for a short period each day.
By also buying an INVERTER to convert the 12 volt DC electricity (from EITHER your car batteries or from the device directly) into 120 volt AC electricity, you can have total energy independence by being able to run your televisions and computers and other appliances on their standard AC electricity, so no element of inconvenience is involved.
These four pictures show the Main Frame of the device, in four different positions, as it will spin around its axle. Notice that two standard 2x10-8 foot pieces of lumber (a total of around $15 cost at any lumberyard), bevel cut at 45 degrees, forms a large square, slightly more than four feet on each side. Since this square needs to STAY square, under significant weight loading, the corners are connected with 6x3/8 lag screws (and washers) and also, with high quality construction adhesive, which is used in all joints.
Then notice that two 2" Pipe Flanges are bolted to the two sides, to attach the short pipe nipples which become the axle upon the whole thing rotates. It IS possible to buy high quality roller bearings or ball bearings (as shown in the photo to the right). IF you have piles of money you want to use up, fine. Such bearings generally cost several hundred dollars each. They ARE capable of having their shafts spin at around 5,000 rpm.
But in the interest of economy, I chose to use PAIRS of ENGINE MAIN BEARING SUPPORTS (face to face) from a junkyard V-8 car or truck engine (as seen here, with 1/2"x8" Lag Screws replacing the bolts that used to mount them in the engine, but now into the top of the (treated) wooden posts. When in the car engine, the bearings needed to endure 3,000 or 6,000 rpm, while THIS device only rotates at around 15 rpm max! In addition, in the car engine, the force provided by the piston is over 6,000 pounds on these bearings, where here, the most we could possibly load on each bearing is about 500 pounds. In both cases, FAR less than the stresses in a car engine. Therefore, I felt that FINDING such surplus Main Engine bearings (for free!) and filling both with some Wheel Axle Grease, (a very yucky job!) should make these crude bearings to last essentially forever. In fact, there HAVE BEEN so many different car and truck engines manufactured that ANY size pipe or shaft might be used and suitable bearing caps found. However, again because of the very slow speed of operation and the minimal stresses on them, I INTENTIONALLY used four bearings which are about an eighth of an inch too large in diameter for the 2" pipe nipples in the device shown in these photos. (which are 2.375" in outside diameter). Not really DESIRABLE, but I want to learn whether the bearings are still OK after some number of years of producing electricity. I am totally confident that they will be.
Also, notice that in TWO of the sides of the square, there is a hole bored through. THESE two holes will trap the large iron pipes which are the Sliding Shaft of the Piston which we will build next.
IF you build this Main Frame out of standard lumber, you may find that different boards have different densities, or have some imperfections where the weight of the two end boards may not be the same. It does not really matter too much in actual operation, as the thing produces IMMENSE amounts of torque to overcome such flaws. However, when I encountered such issues, I used a large woodscrew and a lot of large steel washers, and I screwed the woodscrew THROUGH the stack of washers and into the end of the device. It spins very easily, so then I tested the balance by spinning it a number of times and noting whether all final positions seemed about equal. If ONE position seems to always occur, then you have an imbalance! (IF really high performance electricity production is desired, this Main Frame can be WELDED up out of 7" by 2" CHANNEL IRON, to form the square. The stub axles can then EITHER be welded to that frame OR Floor Flanges can be bolted to that frame.) (After about two years of operation out in my back yard, I now strongly lean toward building the Main Frame out of this Channel Iron and to then build the Cube out of 3/4 inch outdoor plywood instead of the blue foam panels described above. Several violent windstorms have subjected the Cube to Gale and faster winds and I have discovered that large areas of blue foam can start vibrating, resonating, at specific constant windspeeds and it can happen that a section of the blue foam can shatter! Now that I know the device works as calculated, I now lean toward building the Cube to be more sturdy, like 3/4 exterior plywood!)
A further, IMPORTANT, note!
You will shortly see that this thing spins, where the weights at the ends of the sliding shaft can move fairly fast. On the order of 10 mph is common. Now IF you build a sturdy one ABOVE GROUND (as this wooden one is) then you might have as much as 500-pound weights spinning around the device at around 10 mph. THAT could be quite dangerous if someone happens to back into it (as it is essentially quite silent in operation).
Therefore, I STRONGLY encourage you to dig a substantial hole, to put the entire unit underground, OR to build a sturdy cage or building around it, just for safety's sake. However, I chose to build THIS unit where you can SEE the different parts of it and how it works! So I installed two post/pillar supports where the axle shaft is about seven feet above the ground. I will NEVER install very heavy weights on this particular unit, which is why I could get away with WOODEN pillars and WOODEN Main Frame. (And even PVC pipe for some of the pictures of the sliding shaft, simply to more easily stop or slow down what the thing wants to do naturally!) Two-inch PVC pipe is certainly a LOT less expensive than two-inch iron pipe is, but if the weights are very significant, the PVC might either shatter or kink-bend, where the weights might then be set free, NOT a good thing! The same is true of the Floor Flanges, where it might SEEM that the far cheaper PVC flanges would do, but they can SHATTER due to the varying forces on them, and REALLY bad things would happen then! Don't do it!
You might notice later that THIS unit, with its axle at 7-feet height, can have its weights rise to over 12 feet and also to nearly scrape the ground! THAT is part of the "secret" of the system, of raising heavy weights way up and letting gravity do its thing, in this case, as much as 10 vertical feet distance. In scientific terms, you create POTENTIAL ENERGY by raising a weight and then you let that Potential Energy convert into KINETIC ENERGY due to gravity making the weight fall to a lower height. E = m * g * h, or since m * g is the weight, E = W * h. The crude wooden frame and pillars would not endure if I would put 100-pound weights at the ends of the shaft, but you can see right here that having 100 pounds drop by 10 vertical feet is 1000 foot-pounds of energy, and if this is done every two seconds, that is about 500 ft-lb/sec of power, nearly a horsepower (which is 550 ft-lb/sec) and equal to about 650 Watts of power. So I hope you already see WHY it works so impressively!
The actual performance is slightly different than that, where the weight that happens to be at the top actually can only 'fall' about four vertical feet (from about 11.5 feet high down to 7.5 high) and the other weight, at the opposite end of the sliding pipe also 'falls' about four feet (from about 6.5 feet high down to 2.5 high). So this particular Cube, with 100-pound weights max, can only have available 200 * 4 feet or 800 ft-lb, about 30 times per minute, or 24,000 ft-lb/min. Again, one horsepower is 33,000 ft-lb/min, so this particular Cube with 100-pound weights can only create about 3/4 horsepower of mechanical power. So, at best, this particular critter can only produce a continuous maximum of around 550 Watts of electricity. This is actually why I only installed ONE car alternator (on the back side of the Cube, driven by a large round plywood disk as a giant pulley) which is made to create 40 amperes at 14 volts in a car (or about 550 Watts).
Since I forever experiment, I encountered another complication! Even though ONE alternator could handle all the power and electricity that my Cube could make, I still wanted to use a SERIES of 10 used car batteries from junkyards or other abandoned vehicles, in order to have a simple source of 120 volts DC for all the incandescent lights in my house. The complication was that a bunch in batteries which are wired in SERIES can only be CHARGED 'one at a time'! So I had to get a bunch of 12 volt electrical relays to connect my one alternator to only one battery at a time. So I could certainly get the 550 Watts pretty much continuously, but each battery, even if fully discharged, would become fully charged in about an hour and a half. My usual use of electricity was such that, usually, just a half hour of charging was all that any of my batteries actually needed, as I virtually never really seriously discharged my ten batteries!
So a bunch of voltmeters and the relays were necessary so that the Cube would switch among the batteries every half hour or so. In one sense, this was excellent, as in five hours of good sunlight, I could get all ten of my batteries fully re-charged each day (to have far more available electricity than I ever needed any night).
Since GM car alternators have built-in voltage regulators in them, the alternator would reduce its performance once a battery had become fully charged, so this was great, with one exception! Eventually, old car batteries lose their ability to charge, and I found that when ONE of my batteries began to fail, my SERIES CIRCUIT of ten batteries no longer worked, even though NINE of the batteries were fine and fully charged. The voltmeters mentioned above were only necessary to learn when any one of the batteries was having a problem. (actually, once I learned that one battery was failing, I could quickly remove that battery from my series circuit, and my incandescent house lights then again worked fine, although slightly less bright, running at 108 volts instead of 120 volts!)
I am somewhat of a finder of things, and I gradually accumulated a bunch of old GM car alternators. This was the next experiment! The giant plywood disk pulley already had to turn a VERY long fan belt (around 150 inches long) to turn its ONE alternator. I just put more alternators along that fan belt path. Instead of having all 550 Watts being handled by the one alternator, I now had each of a bunch of alternators only handling around 55 Watts, where EACH was now wired to a DIFFERENT battery! No electrical relays were necessary! It had become rather 'automatic' in that any specific battery that had become discharged would simply cause THAT GM alternator to adjust its voltage regulator to charge it. Other batteries that were already fully charged, would just sit there with happy faces!
This situation tends to occur because I use one particular battery, a brand-new one, to also power an INVERTER. That electrical device is pretty common, and it takes 12 volt DC electricity and converts it into 120 volt AC electricity, which can then power computers, TV sets, appliances, fluorescent lamps, etc. That is wonderful except for the fact that I tend to discharge ONE of my many car batteries, while the rest of them remain nearly fully charged!
I have come up with another approach, which seems even better. I now use ELEVEN car batteries. Ten of them are the batteries from old vehicles which are wired in series to supply 120 volts DC for all the house's incandescent lights, the toaster, some electrical space heaters, etc, and they use the 'sequential charging' method with the relays. The eleventh battery is the one NEW battery, which only has one function, to power the INVERTER, to supply the moderate amount of AC electricity that I use for computers and TVs and such. So I again only need to use TWO alternators again!
IF I ever find that I need more AC electricity, I might some day add a THIRD alternator and a SECOND inverter. I seem to have far more ability to light up my house than I actually need, mostly due to the 10 car batteries wired in series! Each battery normally stores around 1000 Watt-hours of DC electricity, so the ten of them nearly always have 10,000 Watt-hours of available DC. If I turn on the lights in every room, around 16 incandescent 60 watt lights, they only use up a total of around 1000 Watts, so my house could probably be seen from Space for at least ten hours, before my batteries would start to be discharged very much. I don't expect that to every happen. I DO like the idea of experimenting to use those ten DC batteries to power three 1500 Watt electrical space heaters, one in my bedroom, one in my living room and one in the main bathroom. With doors usually closed, the bathroom heater should rarely need to turn on for more than a minute each hour, and the other two should be able to cycle on and off by their own adjustable thermostat. My suspicion is that I may not need any heat from my natural gas furnace or from any conventionally supplied electrical heating. The Cube MIGHT be able to supply BOTH all my electricity AND nearly all my house heating. The Jury is still out on that experiment! But it seems very promising!
There seem to be MANY options other than weatherstripping! An old runner that is laid on a carpet near an entry door, seems perfect for this use. I used just the EDGES of the runner, the parts which were smooth and flexible. I am pretty sure that the rubber FLOOR MATS from an older car, could also be cut into strips for this use. I have now tested this, but with NEW cheap floormats from Meijers! Three mats, each $1.99 were cut into four strips each, and then a wood Parting Stop was screwed down over these pieces and into the piston, to form fantastic leakage stoppers! Raincoat material and shower curtain material is not rigid enough, I think. Even semi-rigid sheets of section dividers for a school workbook seems likely to work well.
This piston assembly is supported INSIDE the previously built Main Frame, and the 4.5' long sections of 2" pipe are slid THROUGH the holes in the Main Frame and screwed INTO the pipe flanges on the piston assembly. The Piston Assembly is then essentially entirely supported by the two locations where the pipes pass through the Main Frame, and the rubber weatherstripping also keeps the piston from rotating, so the edges of the plywood piston should never touch any parts of any walls.
Again, I previously mentioned that I used 2" PVC pipe for this construction demo and for the preliminary demonstrations of how it works. Since EITHER the (threaded) iron pipe OR the PVC (with an adaptor piece to threaded pipe, can screw into the two pipe flanges, it is easy to switch. However, again, you CANNOT ALLOW such pipes to ever unscrew by themselves, so a setscrew needs to be added to keep that possibility from happening. Even 2" PVC pipe is not strong enough to resist serious bending when the weight is extended horizontally far out, so iron pipe is really where it's at.
You can see that the photo to the right has the iron pipe screwed into the flanges. But for the demo and the photos, I replaced it with PVC pipe which reduces the performance of the device to where I could STOP it where I needed for photographs! So the following photographs show the unit with PVC pipes.
THIS particular arrangement has the lightest possible sliding weight, with the PVC pipe and NO weights (yet)! This piston and shaft weighs about 41 pounds total. (When the iron pipe is used it is about 64 pounds instead). This means that we will need to provide a maximum of 41 pounds of vertical lift to raise it. We know that we have a piston which has 1936 square inches of area, so that means we would need a MAXIMUM of 41 / 1936 or about 0.021 pound per square inch of pressure inside the lower chamber. Since we will PROVIDE 0.5 PSI, you can see that it has NO trouble in raising this piston up to the top! Using the iron pipe, with the 64 pounds of lift needed, it needs about 0.033 PSI, which is still FAR less than the 0.5 PSI which we provide for it.
Also, when this configuration has the shaft horizontal, and slid all the way out to (either) side, it shows a measured torque of 9.5 pounds at a radius of 6.5 feet from the axle. Multiplying, we see that means that it then can produce 62 ft-lb of torque. We saw above in the math section that the AVERAGE torque is about half that much, or 31 ft-lb. With the iron pipe, these numbers are all about doubled.
Without any weights on the shaft, the unit rotates a little slower, so about 3 seconds to fall (for each half rotation) is common, meaning about 10 rpm. Again, referring to the math section above, we see that we therefore produce about 10 ft-lb/sec of power. This is PLENTY to make the thing rotate, but rather minimal regarding making any electricity, since 10 ft-lb/sec is only around 14 Watts of power, and a Watt or two are used up dealing with air friction and bearing friction and even the rubber scrapers on the piston inside the chamber. Again, with the iron pipe, it can produce an average of about double these figures, or nearly 30 Watts of mechanical power.
The point being, even WITHOUT adding any weights to the shaft ends, it works, and can even make some electricity. The PROBLEM with this is that YOU use electricity like it is going out of style, so you WILL need to make more than that. Adding the weights to the sliding shaft ends does that (as you already know)!
You might also have noticed that there are really few ways where energy can be lost! The total loss of friction in the bearings and air friction is well under one Watt of power, although that slightly increases once the entire cube is spinning, due to the large area that is pushing air out of the way to spin, but even then, not much more than one Watt is lost! It really is AMAZINGLY efficient!
Here are some photos of the piston assembly being in various positions during the unit's rotation. Since there will soon be six walls surrounding it, the movements of the piston will then not be visible, except for seeing the ends and weights sliding in and out as the cube rotates.
This is the natural position it reverts to if NO pressure is being provided to it. The (white here) piston has slid all the way to (either) end stop and that weight imbalance has caused the Main Frame to rotate to stop at a vertical orientation. This is the only STABLE equilibrium that this device can have.
You might notice a big clamp I had to use to keep the thing from doing what it is supposed to do, spin! There is also a thin stick behind the sliding shaft which is supporting the piston and sliding shaft for this photo, which will be provided by the slightly pressurized air, once the enclosing cube is made around it, which will then lift it up and hold it up at the top of its motion. You might imagine that, having done the WORK to raise the piston and sliding shaft (much like the bicycle and barbell examples discussed above) it is now VERY top-heavy, as it now has a LOT of Potential Energy.
The device never actually does this, unless the piston is HELD at the exact center of its range of motion. There is NO purpose for it being balanced, except to take a photograph! THIS is actually called a MetaStable equilibrium. That is like balancing on a bicycle, where there is always the danger of falling over. In the case of a bike, the spinning wheels cause a gyroscopic effect which creates a new force which helps you balance. In this case, if your bearings were good enough, if even a FLY landed on one side of the frame, the MetaStability would be broken and the whole thing would become more and more unbalanced and it would spin to eventually come to be in the first photo of this series (above). THAT situation is the only STABLE equilibrium for this device, where the weight is at the bottom. This device is somewhat unusual in that it has TWO STABLE equilibriums, exactly opposite each other, and that is only possible because the weight of the piston and weights can slide to either endstop.
The weight of the piston and the sliding shaft is here shifted as far sideways as it can go, and so even WITHOUT having any weights on the sliding shaft (yet), the device still creates (during this photo) around 62 foot-pounds of torque in trying to rotate (counter-clockwise). A (wooden) stick was needed to fight its desire to rotate.
Notice how FAR out the weight will be (once weights will be added) at this moment, regarding generating a lot of torque. In the configuration in the photo, even a 50-pund weight, near the end of that extended sliding shaft, would be about 6.5 feet from the axle, and therefore would add about 325 ft-lb of torque to the 62 ft-lbs we already know about! Nearly 400 ft-lbs of torque! Whatever the manufacturer of your car is, IT cannot create that much torque, and even my Corvettes cannot!
At this moment it is generating about its AVERAGE torque, which is around half of the maximum generated two photos above.
You might have realized by now that this device VARIES in rotation speed, and torque, but the (later) presence of a large wooden pulley will somewhat act as a flywheel, and the effect of the belt and alternator also minimizes such variations. But such a variation is NOT critical regarding using car alternators which each have voltage regulators in them, as in a car, the alternator has to deal with the engine idling or racing! For INDUSTRIAL applications of this device (which YOU don't need to worry about!), it is possible to build TWO of these devices and connect them on the SAME axle shaft, but where the two devices are 90° out-of-phase, which virtually eliminates any speed variation.
Related to this last, I also intend to do some experiments with a Low-Performance Version of this unit which does NOT use or need the greenhouse or whatever. I intend to try experimenting with placing shiny metal panels on the ground near the unit, to reflect extra sunlight to the walls of the lower chamber, and also to block direct sunlight from shining on the walls of the upper chamber. It MIGHT be possible to generate a MODEST amount of electricity WITH A SEALED UNIT, in other words, not having to mess with ducts or air valves or a greenhouse. However, the fact that LESS AREA OF SOLAR RADIATION will be intercepted, these experiments will NOT generate the spectacular amounts of energy available from the main design described here.
Those experiments are somewhat motivated by (finally) being able to experimentally test the basic concept of the ORIGINAL version of this device which I had invented and intended to test in April of 2003. The small Village government of Thornton, Illinois seems to have astounding authority, where absolutely no one seems to have any jurisdiction over them. And so, when a part-time, $18/hr, Village official threatened me with immediately Condemning and then Demolishing my house, IF he found that I had even STARTED to build that original demo in 2003, I tried to get help from the Mayor and others who might have had authority over him. But when the Mayor informed me that he had ABSOLUTE CONFIDENCE in (his close friend), that "Building Commissioner", and ANY decisions that he made would not be challenged by anyone, I became (darkly) impressed! Since I LIKED the idea of living IN my house (and I was getting fairly old) I CHOSE not to build the original version of the demo then. Of course, essentially the SAME group of people still run the (very small) Village government, the fact that I am NOW building the (visible) demo that the photos here are of, the possibility still seems to remain that these photos might NOW result in the Village again intending to Condemn and Demolish my house! But I REALLY want to confirm that my reasoning of 2003 was absolutely sound, as I know that it is!
(In 2003, that [part-time] BC actually initiated THREE different actions to Condemn and Demolish my house, for OTHER reasons which were just as bizarre. After the first such threat in June 2003, I realized that I could NOT defend my house and I OFFERED TO GIVE IT AWAY to the local Historical Society, since it is the oldest building in the Village, having been originally built in 1856 as the One-Room Schoolhouse. They were not interested, even in a FREE house! After the third attempt that year, late in September, to Condemn and Demolish my house, I insisted that I know WHEN the Court case was to be heard by a Judge. When the Village asked WHY I wanted to know, I told them that I intended to Appear in front of the Judge with MY evidence of both the quality and sturdiness of my house AND about a number of harassments. I figured I would still lose, and my house was toast, but I figured, at least I would get some Evidence into Official Public Records. Only one day before that Hearing, I called the Court to confirm exact time, and I was told that the Village had dropped their action the day before! SO, there is NO WAY to know what to expect of them now, even though it is more than eight years later. But I have always enjoyed camping, and the BC did say that I would still own the then-vacant property and I could camp on it. Somehow, I suspect that they would then have found some "Violation" from having a tent and sleeping bag on my own property!)
But, in any case, I was never able to confirm that my basic 2003 concept was valid, and now I intend to. (No matter what follows!)
Getting back to the specifics here, I used ONE SHEET of the foam and cut it into two pieces, one 46x46 inches and the other, 46x50 inches. The first was used as the "back wall" of the box, shown in the photo to the right. You might notice that I took to immediately paint EVERYTHING in a dark brown color, because the Village Police had started parking their Cars adjacent to my property. I can only assume that they are looking for yet another reason to try to Condemn and Demolish my house! I couldn't exactly HIDE such a large device, but I noted that they had quickly first seen the WHITE-primer-painted pillars and Main Frame and I saw Village Police cars regularly parked adjacent to my yard. I suppose it might be paranoia that I felt I needed to buy brown paint and use it on everything. I had originally thought that the photos would be more clear with WHITE components, but my rather bizarre local situation forced me to make you struggle regarding all following photos.
It occurs to me that I need to EXPLAIN the apparent paranoia regarding such things! This Village seems to have a Constitution which is somewhat different from the one that I always thought applied in America. For example, the Mayor once explained to me in a casual phone call (on May 7, 2003) that ANY employee of either the Village government or their Police Department ALWAYS had the freedom to ENTER any house or building in the Village, as long as they do not break any windows or doors in the process. When I thought I was correcting his statement regarding a Search Warrant being needed and that ONLY Police could do that, he corrected me in explaining that NO Search Warrant was EVER necessary, and ANY employee of the Village could enter any building. At the time of that conversation, neither the Mayor nor I yet knew that his own (part-time) Secretary had entered my house during the previous year (2002), while I still lived 60 miles away in a different State! (She had entered my locked house at least TWICE and I had even found FINGERPRINTS inside my (locked) house which later turned out to be hers!) I had thought that in America, there was the concept of Private Property and Civil Rights!
It turns out that Police have toys to get into any locked car or house without breaking anything.
On a different matter, the Fire Chief of their (very small) Village had gotten arrested on July 21, 2002 for molesting at least two of the young boys who were in his Fire Cadet program (and apparently many more). Apparently, the Village decided that they needed a distraction to that problem of theirs, and so, about five weeks later, THREE DIFFERENT Village Police Officers made up three DIFFERENT sets of horrific lies about me, which they then told to different young kids, and then the Village has spent the next nine years in repeating one or another of those lies to every resident of the Village! IF this was a TV episode of the Twilight Zone, I would never have believed it! And since NO ONE in the Village government nor the Police ever even TALKED to me, they never became aware that I was a highly respected Christian Minister, known world-wide due to my BELIEVE Religious Information Source web-site which get 50,000,000 hits every year. Since they never even bothered to talk to me about anything, I never even learned that they had developed any of these attitudes toward me or done an amazing assortment of bizarre behaviors toward my house and property and my career as a Christian Minister! It was almost three years later that I began to learn what they had aggressively done to try to destroy me!
In any case, I later learned that there is a US Law that forbids any Citizen from filing any Lawsuit against either a Municipal government or any Police Department. And that, apparently, there is NO ONE who says they have any Jurisdiction over this Village, with the single exception of my good friend in the FBI, who told me that the FBI was swamped with terrorism concerns and neither she nor any other Agent would be able to look into my situation. So I have been "on my own" regarding such behaviors of this small local government and their close friends in the Police Department. You might imagine that such people have continued to harass me for the past nine years, which included the very serious threats to Condemn and Demolish my house in 2003 (mentioned above) and many hundreds of other aberrant (my opinion) behaviors on their part. Interestingly, they happened to choose a TARGET who is not only a respected Christian Minister, but someone who has NEVER been in ANY trouble with authorities, except for a few minor traffic citations and parking tickets during 50 years of driving. Go Figure!
So, yes, I guess I do have an "awareness" which might be relatively similar to paranoia. And NOTHING has ever or will ever be done to punish any of them or to even convince ANYONE in this Village that I am not the evil person they have constantly been told I am! (NOT a person in the Village has talked to me or even acknowledged my existence in the past seven years! They HAVE BEEN effective in spreading their lies about me!) (Apparently, their Constitution never mentions honesty or integrity or telling the truth, or even the fact that they are technically Public Servants, paid partially by MY property taxes!) It is quite impressive to witness the damage that such a group of minor officials can do in destroying the career, reputation and life of a target they choose! I have long wondered how much even greater damage they must do when they happen to choose a target who has actually DONE bad things in his or her life!
Sorry for the info about a subject you could not care less about! But I wanted to try to explain my goofy reason for rapidly painting everything dark brown, which makes it harder on YOU regarding SEEING what is in the photos! (I also only told you about maybe 1% of all they have done to me over the past nine years, as I KNEW you were not interested in wasting even more of your time!)
The other, slightly larger foam panel was used as the "front wall" (facing the camera), shown in this photo. The CENTER of the top and bottom of this had to have a 2" notch cut out of the middle to fit between the top and bottom sides of the Main Frame. This resulted in the top and bottom then EXTENDING an additional 2" wider (downward and upward). There IS a reason for this! The outermost 3" wide at each end is left to extend down that full distance, but BETWEEN that 3" (vertical) strip of foam and the edge of the Main Frame is about 15" wide of foam which is then cut out, on BOTH sides of the main frame, up a total distance of 7" in from the very edge.
This then results in TWO HOLES, each about 7" x 15.5" (at BOTH the bottom and the top), which will become the air passageways into and out of the chamber. That is therefore a total open area of around 220 square inches of airpath. This is actually LARGER than the cross-sectional area of the cold-air return of the furnace in your house! (As you recall from above, the very low air pressure this unit is designed for NEEDS large cross-sectional air path areas to ensure adequate air flow into and out of the two half-chambers. In order for the unit to be able to spin at the best speed, we must FILL the lower chamber in less than about two seconds max. But you knew that! We learned that we need to insert about 38 cubic feet of air into the lower chamber each half revolution, or about each two seconds, which is therefore about 19 cubic feet of airflow per second or about 1140 cubic feet per minute [cfm]. This is in the range of airflows in central furnace ducting, but since we want to need even less pressure to push the air, we lean toward even bigger ducts and airpaths, like the 220 square inch cross-sectional area described above.)
This Front Wall of the Cube seems better presented in some simple graphics. The white large rectangle represents the Front Wall. A blue green circle at the center represents the support flange and the end of the support axle around which the Cube rotates. The four smaller rectangles represent four air passageways. Please note that the (simple) graphics to the right and below all show a MINIMAL effort at the size of the four airpath holes! The description just above described that the top and bottom surfaces of the Cube are FLARED OUT to permit LARGER airpaths. but these graphics do not show the flaring or the enlarged holes. You might notice this in the animations in how briefly the darker-colored open pathways are actually open for airflow! The pairs of air passageways are functionally identical, where the need is to simply increase the cross-sectional area for better air flow, given the very low pressure this works with. As described in the paragraph above, this results in a large 220 square inch cross-sectional area of air path, for each the UPPER interior chamber and the LOWER interior chamber. I am describing this all such that YOU could choose to extend the Front Wall more at the top and bottom, to provide even greater cross-sectional area of air path. The decision on this affects how fast the lower chamber can fill with low pressure air and how fast the upper chamber can empty. I am trying to give you useful information regarding future performance tweaking, whether by increasing the pressure above what I chose to use and/or to make the air paths more free.
You do not see in this drawing that the inside chamber is actually TWO SEPARATE chambers, separated by a large movable (plywood) piston, which can move (up and down in this position) where the volume of the two inner chambers are constantly each changing. You will shortly see that all four of these openings are generally blocked off by a fixed surface that is (nearly) against the Front Wall. Not quite rubbing against the Front Wall to minimize wear and drag and friction, but fairly close so that the very low pressure air barely leaks out between the two large flat surfaces.
For the moment, you should think that the LOWER holes in the Front Wall probably need to RECEIVE warm air, in order to PUSH the piston upward, while the UPPER holes probably need to be open to be able to get rid of air that is being squeezed out of the shrinking upper chamber. However, that is not quite ideal, because as soon as we have sent the warm air into the 'lower' chamber, it is important that the holes in the Front Wall need to get blocked off, at least in the lower chamber of the Cube, to keep pushing and holding the piston up. This might temporarily seem confusing, but it explains why the FIXED PANEL needs to have its holes slanted about 45 degrees or so. The animations below attempt to show this.
The overall idea is to enable the most warm, pressurized air to get INTO the lower chamber, and then keep it there, until the Cube has rotated enough where that chamber has become the UPPER chamber where it needs to get rid of the air in it.
There ARE technological ways to do all this! The description here uses the rotation of the Cube to open and close the valves, without any need for motors or solenoid valves or other mechanisms. If you want to spend money, you CAN avoid all these self-controlled air valvings and simply use mechanisms to open and close the air paths at even more ideal timings than my self-operating valvings do. I tend to follow the KISS approach, in minimizing the various things that can fail! For your device, it is your call!
Note that this Front Wall is constantly rotating. A very crude rotating graphic of the Cube attempts to show this here, without the coming various obstructions that block the view in actual photographs.
Now visualize a similar (plywood) surface, but FIXED in position and tilted about 45°. The precise orientation and the size of the four holes is open to your creative interpretation! Note that at the brief moment that the Cube happens to be rotated appropriately, all four holes line up fairly well. This then (momentarily) provides the freest air supply path of pressurized air IN into the expanding lower chamber (through the lower left holes in this panel), while simultaneously (momentarily) allowing the freest exit path for air which needs to leave the decreasing upper chamber (out the upper right holes in this panel). I recommend mounting some standard window screening over those two upper right holes in the FIXED panel, to keep bugs and leaves out.
This animation was generously provided by Dave Beam. Notice that the
fixed and angled front panel is LARGER than the Cube (so that the holes
in the Cube are never exposed where they might lose air.) Notice also
how briefly the four (dark colored) holes in the Cube are actually
open to carry air!
Mr. Beam also provided an animation which shows when the air can get
into the lower chamber of the Cube and when it can escape the upper
chamber of it.
This final graphic from Mr. Beam shows the giant air duct which (permanently) is attached to the fixed panel, but which blocks off virtually all view of the Cube or anything of how it works! If you are following, the (slightly pressurized) air path therefore will first gradually open up near the bottom of the bottommost fixed lower left air opening (as seen in the above animation), which then soon has the entire air path area open, sending air into the lower chamber. Shortly after, the holes line up less well and soon the entire air source holes are blocked off by solid areas of the Cube Front Wall (as the various areas pass by.)
Note that the available free air path gradually opens up as the Cube rotates and then that available airpath shrinks again. You can see that after a while, the lower chamber becomes CLOSED again, after the pairs of supply holes are no longer open. The amount of air within the lower chamber is now nearly constant, and still pressurized, until a later time when the Cube has rotated enough so that those same moving air holes will now start to line up with the EXIT holes in the (angled) fixed panel.
Please realize that the air path from the supply is HUGE. The size of the tubes that children climb through in playgrounds is not that much bigger than the airpath which I arranged for my Cube! If you want it to really work, you NEED to give it a good chance of getting all the warmed air the Cube needs.
Most of this information is not easily seen in any photographs, as the structures overlap each other, especially the huge air duct! Note also that the angled plywood surface then can easily have the very large air duct screwed to it, where the available supply of slightly pressurized air can be provided by a VERY large air duct. Again, once that giant air duct is installed, the view of nearly all this is obstructed! I do not feel that a large air duct is needed for the EXIT holes, but there DOES seem to be some potential value in recovering this still WARM air to send it back to the air collector 'greenhouse' structure, just to reduce the heat loss of the whole system. I admit that I am rather spoiled with how wonderfully the performance of my Cube is, and an element of laziness enters the picture regarding wanting to install another large air duct and more swing valve air controls!
Other photos regarding the duct flaring seem rather unnecessary, regarding using PL300 foam adhesive to attach the other four cube walls, and then the bits and pieces of foam needed to flare out the (4) air paths. But by taking two 44x44 panels from a 96 inch long sheet of foam, you SHOULD have an 8x48 piece of foam left over, which can then be used to make the flaring pieces.
The bottom and top foam panels came out of a second sheet, this time 46x44 inches. The side panels are similar BUT 44x44 and they need to have a narrow triangular area ADDED to the top and bottom, to close the edges of the widened air path space.
Later Note! My initial concerns about the occasional very powerful winds that Chicago is known for turned out to be justified! Roughly two years after I built the Cube out of the blue foam, there was a storm which included some gusts of around 60 mph winds, and either the foam itself or the foam adhesive was not adequate to the conditions. During that storm, some of the large flat sidewalls of the Cube seemed to start vibrating, and about 1/4 of one of those panels broke loose and flew away! After that, gusts of wind could get inside the Cube walls and gradually, other sections of the foam Cube walls broke apart and flew away. The Cube now needs to be rebuilt, this time using the outdoor plywood that I had first considered using! My fascination with Engineering and calculations let me calculate that 60 mph wind contains around 1080 Watts of mechanical power per square foot, so a Cube wall was subjected to around 17,300 Watts of mechanical power in such a wind gust. Since 746 Watts is equivalent to one horsepower, that means that about 23 mechanical horsepower was sometimes pressing on a Cube wall in such a wind gust. I suppose that it was amazing that the foam walls lasted for the two years that they did! So I no longer encourage building the Cube out of such foam, unless the builder added some additional stiffeners (maybe as external ribs).
Once you have done this, you will see that there need to be cushions or stops to keep the sliding shaft from sliding so far as to have the edge of the piston PASS the inner edge of this air path. (Air coming from the air supply would then PASS the piston and no longer push it to do the useful work of making electricity which we want.) My favorite solution to this is to use two INNER TUBES from very small tires such as used on HAND TRUCKS. The donut shaped inner tube is LOOSE, around each pipe sliding shaft, although there IS value in keeping the inner tubes NEAR the end walls, just to be able to add AIR EXTENSIONS for both inner tubes, because they DO gradually lose air over many months.
It is also possible to mount a few strong compression springs, such as the springs used for the valves in an old car engine, where no need to be re-filling those inner tubes would ever be necessary.
You should now see that the piston, sliding shafts and weights SLIDE outward and upward due to the air pressure you allow into the lower chamber, and then they HIT the small inner tube (or compression springs, which I am getting to prefer) which represents a CUSHION which quietly stops the piston from going any further up. AND the piston is then just barely inside the edge of the new air inlet/outlet passageways.
Obviously, the provisions for the Main Frame and the air passageways are required on BOTH the top and bottom edges of the Front Wall, since pressurized air going in and spent air going out have to happen for EACH of the two half chambers during a complete revolution.
There are then some details that need to be added now.
The air-path needs to be EXTENDED OUTWARD (Sideways), approximately the thickness of the Main Frame, that is 1.5" here. Here is the reason. RIGHT NEXT TO this ROTATING surface (outboard of it), is ANOTHER foam panel, which does NOT rotate. MOST of this fixed panel is solid. The effect of that is to KEEP the pressurized air inside the lower chamber. However, starting at just above the height of the axle shaft, this FIXED area is partially CUT AWAY, in locations that correspond to where the upper (rotating) hole then is at. This RELEASES the trapped air in the UPPER chamber, starting almost immediately after it BECOMES the upper chamber! This actually gives you nearly an entire QUARTER of the rotation to have enough time to RELEASE the trapped pressurized air, in a quadrant which I might call NorthEast in these photos, or "3 pm to noon" (if rotating counter-clockwise).
In the OPPOSITE quadrant, which I might call SouthWest or "9 pm to 6 pm" is a very similar large hole in the FIXED panel. THIS is the one which is (firmly) connected to the supply of slightly pressurized air. Remember that we made sure to provide an air path of about 220 square inches, so the size of this SUPPLY HOLE needs to have at least that area, and so does the duct or passageway supplying it. For the record, an 18" round duct has a cross-sectional area of about 250 square inches! This is a BIG air path!
Notice that it is NOT necessary to go to the complication of FLARING the air path connections. Instead they could just be cut HIGHER into the body of the sidewall to still provide the needed cross-sectional area. However, that then requires that the STROKE of the piston be restricted to a shorter distance, to keep the piston from PASSING the top edge of the inlet air supply. IF that should ever happen, then you would be supplying BOTH SIDES of the piston with pressurized air and it would not move at all! The shorter stroke is fine, but it means that the total energy conversion and therefore the total amount of electricity produced is proportionately less. There are a LOT of choices available to you regarding this unit. I designed it this way (with flared out air holes) to most efficiently use the sheets of plywood and foam. But, with some extra foam available, the cube could be made into a Rectangular prism, where the chamber might be five or six feet LONG (with the same width and height to permit the same plywood piston) so that the piston COULD then move a full four feet or even more (per stroke), without allowing the piston to pass the air-path hole edge. Such a modification might also allow a much larger air-path, such that EVEN LOWER air pressure might be used in it. Still, I recommend that for a FIRST unit, you build it as close as possible to THESE plans, UNLESS you have the Mechanical Engineering and Thermal Engineering education and Degree where you can calculate all of the implications of the CHANGES you want to make!
First, realize that you are going to need a rather large air duct, on the size of 12" x 20" or 16" x 16" to carry the needed airflow. More specifically, you need to have 'valves' which will open or close such airpaths as necessary.
The simplest solution I came up with is a PAIR of very shallow greenhouse-like structures, each 8 wide' x 16' long and just 2'or 3' tall, right next to each other, so they cover a space of 16' x 16'. You can see the very large opening in this end of each 'greenhouse' which can let NEW air into it (when that valve is open). When each is closed, and the similar swinging gate valve at the other end is also closed, the sunlight is absorbed by a black floor which warms up the trapped air in that 'greenhouse'. There is a pendulum-like swinging gate (seen below in green) which alternately closes off this end of each of the 'greenhouses'. In bright sunlight, each of this small size of 'greenhouse' has around 128 square feet of area collecting sunlight, at a little over 100 Watts per square foot, so each 'greenhouse' collects around 12,800 Watts of solar energy!
Note that the two 'greenhouses' are NOT connected and they just happen to be sitting next to each other.
At any instant, ONE of these will have a large swinging valve at the other end open, which RELEASES its slightly compressed air into a very large air duct to send it to the CUBE. We have already mentioned that the other 'greenhouse' is then closed at both ends and therefore 'building up some low grade air pressure due to the sunlight, and therefore it will be collecting new air and warming it up.
So at this end, I made a 'swinging gate' which is just a simple pendulum, which can close off EITHER of two large (16" x 16") openings in this end of the two greenhouses. As the gate swings back and forth, it can close off EITHER, decently completely, while allowing the other opening to be completely open. The pendulum swinging gate is moved back and forth by a very long and skinny 'connecting rod' (shown in black in this drawing) which is moved back and forth by an 'eccentric' on the main rotational axis of the CUBE, which you can see in green in the upper right corner of this drawing. This arrangement ensures that the swinging gate cycles exactly in accordance to the rotation of the CUBE. I leave it to YOU to figure out the appropriate angle of the eccentric on the CUBE axle to open and close these two openings INTO the two greenhouses as appropriate!
At the other end of the two 'greenhouses', a similar arrangement is provided, but the TIMING of that swinging gate is different. It is still timed by and driven by the rotation of the CUBE, but a different eccentric needs to push and pull that connecting rod to correctly be opening and closing those two EXIT air paths.
I made a large airbox which surrounds the outer side of both of those openings, which collects whatever air gets sent out of either half-greenhouse, to then feed the slightly compressed air into the large duct to be sent to the CUBE.
Both swinging gates need to be timed to the rotation of the cube. When one of the CUBE chambers is getting near the bottom of motion, the swinging gate needs to open up one greenhouse-half to release the air pressure into the transfer duct. At that time, the other half-greenhouse is completely blocked off from having any connection to the cube (as that half greenhouse is then 're-charging'). I arranged that by mounting an 'eccentric' to the side of the cube, a few inches away from the axle shaft. This results in a thin metal rod attached to the eccentric to be pulled and pushed as the CUBE rotates. YOU need to figure out where to attach the eccentric to cause the swinging gate to open and close both pathways at the correct times! You can make a cardboard pattern of the swinging gate to see just WHEN you need each of the two greenhouse halves to be opened and closed! Fortunately, everything for the OTHER chamber in the CUBE will automatically work out for you, as it will then use the OTHER half-greenhouse!
The OTHER end of the two half greenhouses ALSO need to have the same large openings and another swinging gate. This one will be driven by a DIFFERENT eccentric on the CUBE, as the openings need to be adjusted differently. THESE openings are to permit NEW air to get into the greenhouse halves, but then to close so that the now new captured air can get heated up before being needed a few seconds later by the duct at the other end!!
OK? You now have the giant air transfer duct feeding the slightly compressed air from one or the other of the two half-greenhouses up to the FIXED large foam panel described a few paragraphs above. In other words, you CONSTANTLY provide slightly pressurized air to and through the air supply duct, but that air is generally BLOCKED OFF by the fact that there is NO HOLE in that part of the CUBE which happens to be passing by the supply duct hole at that moment. It is only when the CUBE has rotated so that the first of the two holes IN the CUBE sidewall start lining up, that the air supply path starts to open up. This now allows that slightly pressurized air to start to get INTO the lower chamber of the CUBE. The CUBE has two holes which each can line up with the air supply duct, so pressurized air keeps getting fed into the lower CUBE chamber for about two seconds. After this time, the solid walls of the CUBE again line up with the air supply duct and no more air gets transferred (until the next, opposite, CUBE chamber air inlet holes will shortly start lining up with the same air supply duct.)
This all results in a slight PULSATION of the pressure inside each half-greenhouse and inside the air supply duct, but as long as the AVERAGE pressures being created are adequate, it all works fantastically! The Sun warms up the small amount of air trapped in a (closed) half greenhouse amazingly fast, especially since we only need that air to be warmed a few degrees temperature. Any extra solar heating which occurs in the greenhouses is simply gravy!
In addition, since everything here is designed to operate on such extremely low pressures, the fact that our swinging gate air valves might lose a little air is NOT a problem at all! There is NO reason to try to build this all to air-tight-standards, and simplicity and ease and economy are more valuable.
Some people are put off by these peculiar swinging gates as air valves. They instead decide to use electrical solenoids or pulse motors to open and close the air paths or even to swing the pendulum swinging gates, at times determined by electrical microswitches.
Fine, but my idea here was an INDEPENDENT system for making electricity, which would automatically open and close air paths by the very rotation of the CUBE, and which might be less susceptible to some day failing when a solenoid failed or such. It also happens to be virtually free regarding the cost of those valves, while Industrial solenoids and pulse motors for such large air paths tend to cost hundreds of dollars each! Go either way you wish!
MY experimental CUBE system worked very well, at least until a severe windstorm blew my foam CUBE walls apart! The arrangement described here only needs around 0.5 PSI pressure increase in the 'greenhouses' which is the equivalent to about 17°F rise. It turns out that the black floors actually collect a good portion of that 12,800 Watts of sunlight which is constantly coming in, and the air inside the 'greenhouses' seems to jump much more than just 17°F, commonly around 50°F. So the accumulated warm air is NOT at just 85°F but often around 120°F inside the 'greenhouse'. This more than makes up for the wasted effects due to the opening and closing of the swinging air gates, such the CUBE receives plenty of air and pressure.
More math! Each 'greenhouse' of this size contains about 260 cubic feet of air inside it, which weighs around 20 pounds. The Thermal Capacity of air is around 0.25 so to warm all this air by 17°F requires about 85 Btus. We learned up above that we only remove around 38 cubic feet of warmed air each cycle, or about 1/7 of the air inside the 'greenhouse'. So we only need to capture around 1/7 of at 85 Btu, or about 12 Btu per cycle. Since we chose a size for the 'greenhouses' as we did, we are capturing around 12,800 Btu of sunlight (per hour), in the (maximum) four seconds we have available to capture sunlight (with both end valves closed), that is 1/900 hour. So we can collect 12,800 / 900 or about 15 Btu during each warming cycle, which is enough for our needs. THAT is actually why I Designed the 8'x16' dimensions for each of the 'greenhouses'! YOU are free to make even larger 'greenhouses' if you do your own math here!
There MIGHT be better ways to collect and transfer the warm air. A much bigger 'greenhouse' could produce a large supply of air like in a closed automobile on a sunny day, maybe 140°F or even 160°F, in much larger quantities. The rapid opening and closing of my swinging valves would then not be necessary, where the CUBE might be driven for several minutes on a single (large) charge of hot air, so the two 'greenhouses' (still necessary!) might only need to open and close once every few minutes! One of the reasons WHY I tried to get people involved in understanding details is that I hope that people will REFINE this concept to become even more useful.
You have probably noted that this description has barely mentioned 'falling water' or 'flowing water' or 'wind energy', being nearly entirely focused on using solar energy. Obviously, it has to be built differently for such energy sources.
In order to permit the unit to work on the lowest possible air supply pressure, I have found value in some comments above, where the infeed and outfeed holes and airpaths are (nearly) a full quadrant in size. This situation gives the air the greatest amount of TIME to flow into and out of the rather large chambers on both sides of the piston, even using the very low air pressure supply I designed this unit for.
IF you find that the piston is HITTING the end stops hard, then you are probably using air at much higher pressure. On the contrary, IF you see that your piston only goes back and forth a couple inches near the middle of its possible stroke, then you are either supplying air at too low a pressure or, more likely, through too narrow an air-path.
There IS another consideration which you might find important! I designed this specific device to have far more capability of producing electricity than you are actually likely to ever need. There IS a reason for this! When we have been discussing the rotation of this device, we have been neglecting the effect of the LOADING of the process of generating electricity. Consider for a moment if you were to use THIS device to supply 15 kiloWatts of electricity. At the time when the sliding shaft is horizontal and the falling weight is at maximum radius, we saw above that it then produces maximum torque and at that instant, it CAN be loaded severely to be producing the full 15 kiloWatts of electricity (although that does SLOW the falling of the weight and the rotation rate of the whole device). Now consider the situation when the sliding weight had just been pushed upward while that sliding shaft is only slightly tilted from being vertical. The geometric angle of being nearly vertical causes much LESS torque of rotation (by the sine of that position angle). Therefore, at that instant, the device produces far LESS torque, to be used to rotate the device and to drive the alternator(s) to generate electricity. It turns out that IF you have loaded it where it has to try to then produce 15 kiloWatts of electricity, it cannot do it due to the reduced torque (at that instant). However, it CAN then produce an easy 1 kiloWatt of electricity at that instant.
The effect being described here is as follows: IF you have NO loading on the device, it SLIGHTLY VARIES in rotational speed as it rotates, being fastest when the sliding shaft is horizontal and being slowest when the sliding shaft is vertical. We USE the fact that the heavy weights are ROTATING as an effective FLYWHEEL in order to smooth out that slight varying of the rotation speed. But we CHOSE to use (GM) car alternators to produce the electricity BECAUSE they are designed to deal with varying engine speeds while still producing electricity! (An alternator which requires CONSTANT rotation speed is NOT compatible with this configuration of this device, which IS the primary reason that this device CANNOT directly produce AC electricity and must necessarily be producing DC electricity [which can then later be converted to AC by using an Inverter]).
If you then INCREASE the loading on this device (by forcing it to produce more electricity), then you WILL notice that the variations in rotation speed become more noticeable. IF you should find that it seems to nearly STOP when the sliding shaft is near vertical, THAT is an indication that you have loaded it so heavily regarding making electricity that it is near the absolute maximum loading. A side effect of such heavy loading is that the AVERAGE rotation speed is much slower, which has the effect of reducing the amount of produced electricity.
Due to this somewhat technical effect, I designed THIS configuration of the device to generally be used at fairly LIGHT LOADING regarding producing electricity. Where it CAN produce as much as 15 kiloWatts of electricity, it is far more desirable (usually) to have it ACTUALLY only producing 3 kiloWatts or even 1 kiloWatt of electricity, where its rotation speed does NOT then noticeably change during rotation. This is FINALLY the explanation for WHY this device was designed to be so bulky and apparently over-designed. It IS, and now you know WHY that was done. While this configuration is producing MODERATE amounts of electricity to charge a bunch of old car batteries, it does it SMOOTHLY and RELIABLY. If, instead, it is loaded heavily to closer to its actual capabilities, the rotation seems more herky-jerky and becomes less reliable regarding supplying the expected electricity.
FOR those who feel they MUST have larger supplies of electricity, such as for commercial or industrial applications, a simple solution is mentioned above, of building TWO of these devices and having them mounted on the SAME axle shaft, but at ninety degrees out-of-phase with each other. This results in ONE of the two sliding shafts to ALWAYS be within 45 degrees of being horizontal, so even though the OTHER sliding shaft is then not very productive, the composite device is then still producing massive torque. The variation of rotation speed due to electrical loading virtually disappears with this configuration of the device, and it CAN then be operated at far higher loading while still maintaining reliability of supplying electricity.
So there have already been people who have told me that they are going to redirect the water from their toilet, in order to GAIN LOTS OF BENEFIT from the (potential) energy that is normally wasted as that water goes down the drain! Ditto, water from rain gutters. And a hundred other IMPROVEMENTS to what I have Designed and Engineered. Of course, no one seems to want to be bothered with any MATH, as their COMMON SENSE tells them what to do!
It is obviously pointless to try to deal with such things, but here is another try. The two gallons of water from a flushed toilet going 8 vertical feet down through sewer pipes, is about 15 pounds, or therefore 120 ft-lbs of potential energy. The fact that one horsepower is equal to 746 Watts and also 550 ft-lb/SECOND, means that the ENERGY available would only be ABLE to make about 6 Watts for 10 seconds. I realize that IS still a POSITIVE AMOUNT, but is it really worth re-plumbing your entire house to do this?
And of course, people talk about exercise bikes and a thousand other COMMON SENSE ideas they came up with. They ARE valid ideas, true. Just not worth doing unless all you intend to do it to recharge the battery in your wristwatch!
One guy even intends to install a swimming pool in an upstairs bedroom that he does not need, to provide water to fall down and drive this device. I hope he has EXCELLENT construction abilities, to make up for his lack of adequate planning! Not counting the structure of such a tank, I would NOT want to VISIT a house which has 64,000 pounds of water above my head! And even THAT would only be able to provide significant electricity for around 16 minutes, before the pool would be empty and another 64,000 pounds of water was needed!
You might even eventually choose to build a SECOND such device (for around another $150, plus a bunch of used batteries), and you could re-charge the batteries for any golf cart or Electric Vehicle (for free) and therefore also eliminate most or all of your need and usage of gasoline for your vehicles!
This is a moderate-sized system and it is ON YOUR PROPERTY. There is NO need to have to rely on a wasteful Power Grid to get electricity to you.
Since this device only requiring around $150 for the materials to build it, we might look at the Amortization of it (something I ALWAYS do with any alternative energy device)! We calculated above that around 14 kWh of electricity can be provided all day, every day. Current electricity in the USA (including a substantial Delivery Charge, taxes and assorted other added costs), is commonly around 15 cents per kiloWatt-hour. So this device would produce 14 kWh * $0.15 or about $2.10 worth of electricity EVERY DAY! IN LESS THAN THREE MONTHS after building it, 91 days, we would have received 91 * $2.10 or about $190 worth of electricity! IN OTHER WORDS, in less than THREE MONTHS of use, it would have ALREADY completely paid for itself! And then EVERY YEAR afterward, you would receive around $750 worth of electricity (at current rates!) VERY few products ever amortize their own purchase price or their construction cost in even ten or twenty years! THIS system does it easily in the first three months of use!
There may NOT be any significant need for gasoline or coal or natural gas or uranium or ethanol or hydrogen or even hydroelectric power plants. And the need for the Power Grid seems likely to disappear if each person simply makes their own electricity in such large quantities that they can convert some of that electricity into being used for their driving needs, for heating their homes, or for nearly any other energy intensive needs.
Unfortunately, the giant corporations which receive billions of dollars from you and me every year for utility bills will NOT be pleased with this system which can and will make most of their profit-centered activities irrelevant to us! I suspect they may not be that pleased with me either, for letting people know about this and how to do it for themselves!
The Environment might greatly benefit by having MANY of the causes of artificial disasters to end as well as the raping of the planet to get to any remaining fossil fuel deposits. It seems really astounding that we dynamite off the tops of mountains and then bulldoze those mountains out of existence, just to get access to coal or copper or bauxite (aluminum) or other natural materials which happen to be in those mountains. We humans are certainly a piece of work!
IF the device is to use WATER, then the DIFFERENTIAL VOLUME should be as SMALL as possible to not consume any more water than necessary to avoid being wasteful. Therefore, the shape would be maybe 16" x 16" square by just 4" thick. The piston would then only move a maximum of just under 4", but with tremendous force, 2 PSI would provide 512 pounds force, so heavy weights (over 200 pounds each) could be used. The device could then be fairly SMALL and still produce a lot of electricity.
IF the device was to use AIR then the size might be 48" x 48" by 48" thick, as described and discussed above. This would allow even heavier weights to be used, but where much greater airflows could be used (where high speed water flow would have more turbulence and more wasted energy). THIS configuration could use up to 450-pound weights, and operate on 0.5 PSI air pressure, as discussed above. The large quantities of air could then be created by simply warming ANY air from 65°F to 82°F (only a 17°F temperature increase of the air, whether by sunlight or a bonfire or a thousand other ways.
The large air-based versions need MUCH more space because the weights can move so far in and out, so they would NOT be convenient for a closet or other small space. Maybe a water-based system might be best for such compact needs.
IF "only water" or "either air or water" is to be used, then no plywood would be used and 1/4" thick PVC or Lexan or other plastic could be used for construction instead, then requiring triangular braces or gussets of that same material such that standard solvent cement could join all the parts together. A few brass woodscrews might still be used for security.
The whole thing COULD be built out of 1/4" plate steel, but I see no reason to do that. The two "sidewalls" have standard "pipe flanges" bolted in their centers to provide the attachment for the pipe nipples which are the half-axle-shafts that the entire thing would rotate around.
A nearby MIRROR underneath the rotating cube could reflect sunlight UP onto the bottom half of it and the upper half might have insulation and shielding from the sunlight. This would be for a lower-performing system which did not then need to use the connected "greenhouse" and the mirror might also provide extra solar warmed air for the input. That SHOULD collect up to 2,000 Watts of sunlight all day (or the far more 25,600 Watts of sunlight if the large connected greenhouse was used!)
If the air is warmed even just 5°F, then the created pressure should increase by around 0.2 PSI. With the 44x44 piston area, that should still create 390 pounds of total force on the piston. If 300 pounds of weights were used on the sliding rod, and they shifted four feet vertically each revolution, that would be around 1200 ft-lbs. At around 15 rpm, it would rotate, that would be 1200 ft-lb * 15 18,000 ft-lb/min or a little over half a horsepower or around 400 watts of mechanical power.
The greenhouse or the many other possible energy sources WOULD generally warm the air much more than just five degrees, where I suspect that the incoming sunlight might EASILY provide as much electricity any house should ever need (during sunlight). Many options would be available during night (including the Sub-Basement energy supply at up to 150°F temperature).
It turns out that around the 1920s, thousands of people thought about such subjects and hundreds of them even went to the trouble and expense to get US Patents on their ideas. History has shown us that far more than 99% of them had wasted their time and trouble and expense! We will discuss one idea of that era that gives every appearance of being a brilliant idea! It even works as claimed, and the only shortcoming was that the Inventor had not fully done the math regarding HOW it would work. IF you only wanted to recharge the battery on a wrist watch, his invention would have been excellent. But not really for anything else, such as the application which I designed my system for, to generate serious amounts of electricity.
Actually, you may even have seen a small model of that invention, nicely rotating a small device fairly slowly. The models I have seen were generally made nearly entirely of glass. Here is the description of that invention. Consider two glass balls which are maybe two inches in diameter. They are connected by a narrow glass tubing, which penetrates the nearer side and goes exactly through the center of both glass balls, nearly to the farthest surface. If you understand this right, then you know that air or water could flow back and forth to the glass balls through the narrow tubing, and that the whole assembly is perfectly balanced, for an rotating axle that you might attach to the exact center of the narrow tubing.
Next, you have to remove ALL the air from this assembly with a very strong vacuum pump, and then add enough pure water to completely fill ONE of the two glass balls, and then the chamber is again perfectly sealed. The device as invented included four of these sealed assemblies, so they were at each 45 degree angle, but we only need to discuss one here to learn how it works.
Now add a small fire below the lowest part of it, which is obviously the glass ball which happens to presently be filled with water. Remembering that there is no air inside the assembly, that can make water boil at very low temperature, even 80°F or 60°F. So now what happens is that some of the water boils in the bottom globe and creates a little bit of water vapor, which is at higher pressure. The way the narrow glass tube is attached, any increase in pressure forces some of the water to get pushed UP through the narrow tube, all the way to near the top of the entire assembly, where the water overflows and starts to fill the TOP glass globe. Got it? The HEAT from a fire causes some water to warm up and boil, which then forces some of the water which is in the bottom globe, up the tubing and into the top globe.
You might have noticed a similarity to the discussion of the unbalanced barbell and the way we cause the weights in our cube to move upward. In any case, after we have caused MORE THAN HALF of the water to get sent from the bottom globe to the top globe, that device begins to be top-heavy, and it then has to rotate half a turn due to gravity.
For a very small toy model of that invention, a small fire could be used or a fairly large (hot) light bulb or even the Sun's heat can be used to drive the toy, and it looks pretty impressive in slowly rotating. So as a conversation starter, it is great.
What is the math that the inventor of that device never did? Given any realistic source of heat, one needs to figure out how much water must be raised (for the dimensions described, about 2 ounces of water or 1/8 pound is likely) and how high that water needs to get raised (about one vertical foot for the toy devices I had seen. That 2 ounces of water moves from the lower to upper globe in about ten seconds. So we had to add 1/8 pound times one foot in every ten seconds, or about 0.0125 ft-lb/second. We can convert that into Watts and get about 0.02 Watt of power. At least one third of that power gets wasted in the way the upper glass globe fills (from the top), so we needed to use about 1/80 Watt of power in raising the water. No matter how we might try to convert the resulting rotary motion due to gravity into electricity, but we might hope to get maybe 1/200 Watt of electricity in a good day!
That invention also has disadvantages due to the glass globes losing heat from radiation and convection, which reduces the efficiency even more. But as a toy device, the tiny amount of power which it can produce due to gravity rotating it, can keep it rotating for as long as there is conversation to be had! But it cannot realistically be expected to also produce bonus power which might be converted into electricity.
The point here is that the Invention of the 1920s certainly worked as the laws of science permit, and so it can sit there merrily turning for hour after hour. But the heat source, whether it is a small fire or the heat of a light bulb or the heat of the Sun, must provide plenty of heat so that 1/80 Watt of power is available to raise the water, and in fact, many Watts of such power sources are necessary for those toys to turn.
So when someone comes up with that idea (again!) today, they seem to never do sufficient analysis to know how it might work or not. This situation happens A LOT when people decide to fool around with solar panels or windmills, and they tend to eventually get to the point where the windmill CAN power its own rotation, but just not any more to actually make into electricity. See the lesson here?
However, I personally find it fascinating to watch such a toy heat engine methodically rotating for hours. I guess it is sort of like watching a candle burn, where not much really happens, but it is still mesmerizing to watch!
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C Johnson, Theoretical Physicist, Physics Degree from Univ of Chicago