开云体育

Old steel or alloys (AlNiCo for example) magnets used on car, bike or telephone magnetos, galvanometers, ...? were easily losing their field strength when decoupled from their armatures or when shocked or annealed. Modern ones e.g. Neodymium are far more strong, they almost don't or, at least insignificantly do.

Consequently, from time to time or mandatorily if dismantled these magnetic fossils were needing a re-magnetization that nowadays can easily be done. It's a matter of Ampere x turns.

Here's a link that will make Jacques' life, otherwise for English people googletrans is your friend !

This is only a piece of public information, not a how-to procedure. Of course, it's up to you to protect yourself. I'm not responsible of any kind of accident that might occur.