I got this idea from a toothbrush. Seriously. The electric toothbrush recharged without any physical contacts. Near as I can figure there was a coil in the base station, and a coil in the brush, and it worked as a transformer would. Anyways, for various reasons, I've wanted a nice pack of rechargable batteries in a backpack.

My idea is to put a coil in the wall, and a coil inside the back of the backpack. Put AC through the coil in the wall, hang up the backpack over that spot, then get AC inside my backpack. I only know a tiny bit about transformers, *I like digital electronics more* so is my idea unworkable, or feasible.

Click to view attachment

Hope someone can provide some insight.

Thnx

I'm sure it would work in principle, but only if you fancy waiting several days for your backpack to charge, and erasing any nearby magnetic media.

Also you will need a way of getting AC > DC in the backpack and getting the right voltage to charge the batteries considering the voltage across the coil will vary depending on distance from wall.

Blasted in principal. Why aren't things that work in principal ever practical? *sigh*

Try searching the web for info on Nikola Tesla.He was very good at transmitting energy through the air to other devices with absolutely no harmful side effects.

Nahh. Most of that was high frequency high voltage stuff. Not too practical to build a tesla coil into my wall or backpack. Tesla took his best work to the grave with him anyway. *sigh*

This is actually already developed. A few years ago, a man had the first full artificial heart installed. It was quite a piece of work. Since it used mechanical means, it has to be recharged. No wanting to put plugs in him the opted for a method where it recharges overnight while he is sleeping provided he is within 5 (?) feet of the charge station. Im not sure about the method, but it sounds similar to your backpack scenario.

Just a thought.

Or you could just buy one of these:

http://msnbc.msn.com/id/9245155/

It recharges automatically without a power outlet.

I have a digital oral thermometer from the 80's that uses this concept. These were used in hospitals, and the unit had to be fairly waterproof, thus the batteries were charged by an induction coil. Wouldn't cause any problems with other equipment, as long as it was only energized when the mating coils are in position.

Garry