For my grade 10 science project, my partner and I set out to hook a generator to an electric motor. The idea was that the motor would drive the generator which would drive the motor again in perpetuity. Now we weren’t so naive as to discount the idea of resistance. When you pass current over a wire, a certain amount of that power is lost to resistance (lost as heat). We were proposing using superconductors instead of the wires we used in our mock-up. We also proposed using magnetically suspended bearings and running our set up in a vacuum to eliminate all friction. Even if it was possible to eliminate all friction, there was still another problem for our design.
In grade 10, we had yet to be introduced to the laws of thermodynamics which strictly forbid such arrangements. A physics teacher came over to grade our project and after a quick glance he said: “background emf.” We stood there trying all permutations in our mind of what ‘emf’ could possibly stand for. He asked: “Background EMF? Have you taken grade 11 physics?” We dejectedly shook our heads to indicate that we hadn’t. He continued while leaving our booth “well you need it!”
Having recovered from our tragic defeat, and some 18 years later, I can explain the ‘travesty’ we had committed against physics. Background EMF stands for background Electromotive Force. What this means is that when you use a current (electrical power) to drive an electric motor, the electric motor as a result of its operation generates an opposing current to the one driving it. In a sense it is a sort of electromagnetic resistance. In short, what it says is that the system we built could never work, even if we used super conductors as wires and ran in a frictionless environment.
For the lay reader, a generator and an electric motor are virtually the same device. One generates electricity from motion and the other converts electricity into motion. In fact if you were to take an electric motor and hook up a volt meter to it and spin it, you’d discover that there voltage was generated just as if it were a generator. At the core of either device lies a loop (or loops) of wire and magnets. Recall that I said if you spin an electric motor, you generate a current. Well that’s exactly what background EMF is. As the motor spins, it also generates a current in the opposing direction to the current driving it.
Now along comes Thane Heins.
http://www.thestar.com/sciencetech/article/300042
http://www.thestar.com/Article/300041
Through experimentation, he has come up with an arrangement which theoretically feeds background EMF back into the electric motor in a way which ADDS to the current driving the motor. In so doing he’s (theoretically) created a positive feedback loop which causes the motor, not only to maintain speed, but actually to accelerate.
This flies in the face of physics, specifically the laws of thermodynamics which say that you the amount of energy in the universe is constant and in a closed system, you can’t create energy. Heins’ system is what’s called a closed system, that is there is no external input of energy, hence it should not be able to create any more energy than was inputted: ie, the wheel should never gain speed, if anything it should always slow down.
Claims of perpetual motion on the Internet are about as common as claims of a new fad diet which will slim you with no effort. If you catch my drift, such claims are usually discarded as junk science. In this particular case though, it has appeared to have attracted the attention of several physicists, one of whom from MIT, who haven’t admitted that he’s achieved perpetual motion, but also haven’t been able to point out any obvious error in his experimental setup and claim.
Even if this fails to be perpetual motion, perhaps some of the concepts can be adapted to produce newer and more efficient electric motors. At the very least, the exploration of Heins’ design and concepts should help illuminate us all. To see video and for some further reading, please see:
http://www.g9toengineering.com/backemf/demonstration.htm
