The Sonicare toothbrush - how does it charge?
 

I've been using one for years and have never paid much attention to the technology behind it. It's probably really simple but I can't wrap my brain around it.

Ok, so you put it in its holder, dry or wet. The holder is plugged in but the toothbrush itself just sits in it, rather loosely even. No pins, connectors or plugs on the toothbrush. Somehow, the little motor gets a charge from the holder.

Electromagnetically? Is this sort of like the free gererator?

Are you familiar with how a transformer works?

transformer

The core in this article doesn't have to be iron it could be air. All that is necessary is the magnetic flux is common to both coils.

p.s. I don't have an electric toothbrush so this is a guess at how it works. I lead a simple life.

Forget the transformers; what's a toothbrush?

http://forums.pelicanparts.com/uploa...1154907915.jpg

eaarrhhh! Nasty!