On Mon, 15 Apr 2013, David Roberson wrote: > Good point Eric. I saw a short video and the fan blade was tiny. > About the size of a large model plane prop. I would guess a couple of > watts, but it is difficult to determine.
A fan is unprofessional, it's a publicity stunt, a distraction. If they're *calculating* the fan wattage, be even more suspicious. They could be way off, using it to fool themselves, or even choosing such a method to avoid simple obviuous tests. Instead, ignore the calcs and get an empirical estimate by running an exactly identical fan device with a DC motor, and measure the operating volts/amps. Or better, get rid of the fan, instead use their device to power a DC generator hooked to a resistor. But that would be simple unavoidable truth, not a flashy fan which performs *apparently* impressive work, while actually their watt claims may evaporate if investigated. Estimating magnet energy: if your magnet is composed of many long thin magnet rods, you can let each rod flip over into "attractive mode" while performing some work. When half the rods have flipped, and you have a random pack of strongly-attracting NSNS rods, that's a fairly close approximation to an unmagnetized material. "Unmagnetized" doesn't exactly mean random, instead it means that all the flux paths are circles confined within the metal. Also this: Unmagnetized: Two horse-shoe magnets held N-to-S to form a closed ring, with zero flux outside the metal. Magnetize: Force one of the horse-shoes to rotate 180deg to again form a ring, but where the N pole is now against the N-pole of the other, and the flux from both halves is extending out into surrounding space. And, the net work needed to rotate one horseshoe against repulsion? That's the energy needed for "magnetizing." (((((((((((((((((( ( ( ( ( (O) ) ) ) ) ))))))))))))))))))) William J. Beaty SCIENCE HOBBYIST website billb at amasci com http://amasci.com EE/programmer/sci-exhibits amateur science, hobby projects, sci fair Seattle, WA 206-762-3818 unusual phenomena, tesla coils, weird sci
