Perpetual Motion = Unlimited Power….Sort of…

The serious pursuit of perpetual motion has always intrigued me. Of course I know the basic science of conservation of energy and the complexities of friction, resistance, drag and less than 100% mechanical advantage that dooms any pursuit of perpetual motion to failure…but still, I am fascinated at how close some attempts have come. One college professor built a four foot tall Ferris wheel and enclosed its drive mechanism in a box around the hub. He said it was not perpetual motion but that it had no inputs from any external energy source. It did, however, make a slight sound out of that box. The students were to try to figure out how the wheel was turning without any apparent outside power source. It turned without stop for more than two years and none of his students could figure out how. At the end of his third year, he introduced his mechanism. He was using a rolling marble design that was common for perpetual motion machines but that also had been proven to not work. What he added was a tiny IC powered microcircuit feeding a motor that came out of a watch. A Watch! The entire 4 foot high Ferris wheel needed only the additional torque of a watch motor to keep it running for nearly 4 years!

This got me to thinking that if I could find a way to make up that tiny little additional energy input, I could indeed make perpetual motion. Unlike most of my other ideas, this was not something that could easily be simulated in a computer model first. Most of what does not work in perpetual motion is totally unknown until you build it. I also knew that the exchange of energy to and from mechanical motion was too inefficient to ever work so I concentrated on other forms of energy exchange. Then I realized I had already solved this – back in 1963!

Back in 1963, I was a senior in high school. Since 1958, I had been active in science fairs and wanted my last one to be the best. To make a long story short, I won the national science fair that year – sponsored by Bell Telephone. My project was “How far will sound travel” and my project showed that the accepted theory that sound diminishes by one over the square of the distance (the inverse square law) is, in fact, wrong. Although that may occur in an absolutely perfect environment of a point source of emission in a perfectly spherical and perfectly homogeneous atmosphere, it never ever occurs in the real world.

I used a binary counting flashing light circuit to time sound travel and a “shotgun” microphone with a VOX to trigger a measure of speed and power of the sound under hundreds of conditions. This gave me the ability to measure to 1/1000th of a second and down to levels that were able to distinguish between the compressions and rarefaction’s of individual sound waves. Bell was impressed and I got a free trip to the World’s Fair in 1964 and to Bell Labs in Murry Hill NJ.

As a side project of my experiments, I attempted to design a sound laser – a narrow beam of sound that would travel great distances. I did. It was a closed ten-foot long Teflon-lined tube that contained a compressed gas – I used Freon. A transducer (a flat speaker) at one end would inject a single wavelength of a high frequency sound into the tube. It would travel to the other end and back. At exactly 0.017621145 seconds, it would pulse one more cycle at exactly the same time that the first pulse reflected and returned to the transducer. This was timed to exactly coincide with the first pulse so that it was additive, making the first pulse nearly double in amplitude. Since the inside of the tube as smooth and kept at a constant temperature, the losses in one pass through the tube were almost zero. In less than 5 minutes, these reinforcing waves would build the moving pulse to the point of containing nearly all of the gas in the tube into the single wave front of one pulse. This creates all kinds of problems so I estimated that it would only be about 75% efficient but that was still a lot.

Using a specially shaped and designed series of chambers at the end opposite the transducer, I could rapidly open that end and emit the pulse in one powerful burst that would be so strong that the wave front of the sound pulse would be visible and it would remain cohesive for hundreds of feet. It was dense enough that I computed it would have just over 5 million Pascal’s (Pa) of force or about 750 PSI. The beam would widen to a square foot at about 97 meters from the tube. This is a force sufficient to knock down a brick wall.

One way to make the kind of transducer that I needed for this sound laser was to use a carefully cut crystal or ceramic disc. Using the property of reverse piezoelectric effect, the disc will uniformly expand when an electric field is applied. A lead zirconate titanate crystal would give me the right expansion while also being able to respond to the high frequency. The exit chambers were modeled after some parabolic chambers that were used in specially made microphones used for catching bird sounds. The whole thing was perfectly logical and I modeled it in a number of math equations that I worked out on my “slip stick” (slide rule).

When I got to Bell Labs, I was able to get one scientist to look at my design and he was very intrigued with it. He said he had not seen anything like it but found no reason it would not work. I was asked back the next day to see two other guys that wanted to hear more about it. It was sort of fun and a huge ego boost for me to be talking to these guys about my ideas. In the end, they encouraged me to continue thinking and that they would welcome me to work there when I was old enough.

I did keep thinking about it and eventually figured out that if I can improve the speed of response of the sensors and transducer, I could shorten the tube to inches. I also wanted more power out of it so I researched what was the gas with the greatest density. Even this was not enough power or speed, so I imagined using a liquid – water – but it turns out that water molecules are like foam rubber and after a certain point, they absorb the pulses and energy too much. The next logical phase of matter was a solid but that meant that there was nothing that could be emitted. I was stumped…for awhile.

In the late 1970’s I figured, what if I extended the piezoelectric transducer crystal to the entire length of the tube – no air – just crystal. Then place a second transducer at one end to pulse the crystal tube with a sound wave. As the wave travels the length of the crystal tube, the compression and rarefaction’s of the sound wave pulse create stress or strain on the piezoelectric crystal, making it give off electricity by the direct piezoelectric effect.   this is how a phonograph needle works as it bounces on the grooves of the record. 

Since the sound pulse will reflect off the end of the tube and bounce back, it will create this direct piezoelectric effect hundreds of times – perhaps thousands of times – before it is reduced by the transfer into heat. As with my sound laser, I designed it to pulse every single bounce to magnify the amplitude of the initial wave front but now the speed was above 15,000 feet per second so the pulses had to come every 0.0001333 seconds. That is fast and I did not know if current technology was up to the task. I also did not know what it would do to the crystal. I was involved in other work and mostly forgot about it for a long time.

In the late 1980’s, I now was working for DARPA and had access to some great lab equipment and computers. I dug out my old notes and began working on it again. This time I had the chance to actually model and create experiments in the lab. My first surprise was that these direct piezoelectric effects created voltages in the hundreds or even thousands of volts. I was able to get more than 10,000 volts from a relatively small crystal (8 inches long and 2 inches in diameter) using a hammer tap. I never thought it would create this much of a charge. If you doubt this, just take a look at the Mechanism paragraph in Wikipedia for Piezoelectricity.

When I created a simple prototype version of my sound laser using a tube of direct piezoelectric crystal, I could draw off a rapid series of pulses of more than 900 volts using a 1/16th watt amplifier feeding the transducer. Using rectifiers and large capacitors, I was able to save this energy and charge some ni-cads, power a small transmitter and even light a bulb.

This was of great interest to my bosses and they immediately wanted to apply it to war fighting. A friend of mine and I cooked up the idea of putting these crystals into the heels of army boots so that the pressures of walking created electricity to power some low power devices on the soldier. This worked great but the wires, converter boxes, batteries, etc.,  ended up being too much to carry for the amount of power gained so it was dropped. I got into other projects and I dropped it also.

Now flash forward to about 18 months ago and my renewed interest in perpetual motion. I dug out my old notes, computer models and prototype from my DARPA days. I updated the circuitry with some newer faster IC circuits and improved the sensor and power take-off tabs. When I turned it on, I got sparks immediately. I then rebuilt the power control circuit and lowered the amplitude of the input sound into the transducer. I was now down to using only a 9-volt battery and about 30 ma’s of current drain to feed the amplifier.   I estimate it is about a 1/40th watt amplifier.  The recovered power was used to charge a NIMH battery of 45 penlights of 1.2 volts each.

Then came my epiphany – why not feed the amplifier with the charging battery! DUH!

I did and it worked. I then boosted the amplifier’s amplitude, redesigned the power take-off circuit and fed it into a battery that was banked to give me a higher power density. It worked great. I then fed the battery back into an inverter to give me AC. The whole thing is about the size of a large briefcase and weighs about 30 pounds – mostly from the batteries and transformers. I am getting about 75 watts out of the system now but I’m using a relatively small crystal. I don’t have the milling tools to make a larger properly cut crystal but my modeling says that I can get about 500 watts out of a crystal of about 3 inches in diameter by about 12 inches long.

I call my device “rock power” and when I am not using it for power in my shop or on camping trips, I leave it hooked up to a 60 watt bulb. That bulb has been burning now for almost 7 months with no signs of it diminishing. It works! Try it!!!

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