Reply To: Recharge Magnets on Fly Wheel

[wmohat]

foot_doctor: We very quickly noticed that the location of the magnetic field probe (most likely an analog Hall sensor of some type)….. the location made a BIG difference in the amount of field strength we measured. The “sensor” was in a tiny aluminum tube, I assume suspended somewhere in the middle of the tube housing.

Anyhow, we settled on holding the sensor FLAT to the surface of the magnet pole pieces, both in the DEAD CENTER of the pole, and at ONE EDGE of the pole (right on the center line). This made our measurements repeatable. Curiously, the field strength at the edges of the poles was often twice the strength measured at the dead center.

Also odd….., the old steel magnets were measured at about 100 to 500 Gauss…… but not higher, and we expected 1000 to 2000 gauss. The newer Alnico magnets were measured at 500 to 1000 gauss, and we expected 2000 to 5000 gauss for those. We are at a loss to explain why all these measurements are this low……….the teslameter we used was known to be a good unit. Very strange.

Anyhow, the power of your magnetizer doesn’t have ANY EFFECT WHATSOEVER on how much “strength” or magnetic charge you can put on a specific magnet. The maximum amount of gauss a magnet can hold is determined by the material it is made out of. If I take a “dead” steel magnet and put it on my Stevens unit, I might get 500 gauss out of that magnet. If your friend put it on that massive magnetizer that you described, it would be exposed to maybe 20 times greater magnetizing field strength………but………it WILL NOT BE ABLE TO HOLD any more gauss after it was “charged” than if it was charged with my simple Stevens unit. Those Stevens units have enough strength to charge steel and Alnico magnets, but they are INADEQUATE to charge rare-earth magnets like Samarium Cobalt and Neyobium types………those magnets require the higher field strength that your friend’s unit can generate. BUT…..the limit is on the magnetic material. You can’t charge a 12V battery to 24V…..right? Same thing……if a magnets’ material can only hold 500 gauss, that’s all you’ll ever get out of it, no matter how powerful your “charger”.

Now, you CAN machine a flywheel and put in rare-earth magnets……but…..then you’re going to have troubles with overvoltage breaking down the insulation in your coil, or punching through the dilectric in your condensers……

AND….that’s our next topic of discussion……we are going to do a serious study of condensers, and matching condensers to coils for maximum spark (without melting your points). This promises to be a very interesting little investigation!

–Bill

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Bill Mohat MS/CIS, BSEET, CCNA

"You can avoid reality, but you cannot avoid the consequences of avoiding reality." --Ayn Rand **********************************************