Demagnetizer
Demagnetizer
(OP)
I need help building a demagnetizer. As far as I know, I can demagnetize a steel part by passing it slowely through an alternating magnetic field. So I want to make a large solenoid by wrapping wire around a large cardboard tube and then passing the part through it. But I don't know enough about electricity and magnetism to know what size wire to use and how many turns. I have either 120 or 240 volt AC.





RE: Demagnetizer
Summarizing the above: Flux = Amp-turns / Reluctance
where Reluctance ~ Mu0 * Area / (air-path-length).
If you can get your hands on donut shaped piece of core steel with one piece cut out of the donut (similar to horseshoe, but bent a little more), then you can insert the piece into the opening in the horseshoe.
You will have to monitor the current and temperature as you go to avoid exceeding insulation temperatures, starting a fire, or tripping a breaker. Current should vary in proportion to Voltage / [number-of-turns(^2)] for given geometry. Also highest current occurs when there is no piece inserted into the flux (air-path-lenght of flux is longest).
Just some thoughts and not intended as a substitute for adult supervision
RE: Demagnetizer