Charging by induction?

[07accordEX]

Hey, I was wondering about charging by induction (lay object on top of a pad or something and it would charge by itself). I am building it for a science museum and wanted to ask here since a lot of you guys know a lot about circuitry and stuff.

Could someone point me in the right direction as to how to build this thing? I can get the parts and equipment our budget would be around $500.

 

[louie]

Are you interested in the design and build? Or buying commercially available product to fit a function, like these:
http://seattletimes.nwsource.com/html/personaltechnology/2010081052_ptwireless17.html

 

[07accordEX]

I would much rather buy because of simplicity, but how do I make this work for my application is another thing? I could buy the mat and design/use one of their battery circuits in my own battery.

But the problem is this is for a Mars Land Rover exhibit so the rover would be on all the time, and I am not sure if the battery being charged would mess with the electronics

 

[Hamilton Felix]

If you want one to take apart, heck maybe even turn the body into a flashlight if you're creative -- find a Sonicare toothbrush. But you'll have to search for a while. They last pretty well, and people don't often toss them out.

I must admit, I've often wanted to crack open a Sonicare. We have two right now. If either one quits, I'm going to pull it apart. But that's a good example for you; it's waterproof, proven for years, about flashlight sized, and available everywhere.

 

[DIWdiver]

I would much rather buy because of simplicity, but how do I make this work for my application is another thing? I could buy the mat and design/use one of their battery circuits in my own battery.

But the problem is this is for a Mars Land Rover exhibit so the rover would be on all the time, and I am not sure if the battery being charged would mess with the electronics

How much power do you need to provide? Will the rover be moving around and coming back to home to recharge?

The more power you need, the more electrical and magnetic noise the charger is going to create. But unless the electronics are particularly sensitive, or you need lots of power, there shouldn't be a problem. I think the toothbrush and shaver chargers provide something like 1 Watt, and it looks like the PowerMat might provide a couple of watts.

There's a fair amount of engineering that goes into those things, so unless you're into a big project, I'd recommend trying out the commercial units.

Now if you want some real power, get a few hundred yards of 6 gage wire and lay it in a big circle under a 400 kV high tension line. Can power your house, but pisses of the power company.:devil:

 

[07accordEX]

I am hoping to charge at atleast 1 - 2 amps. And the battery packs are 7.2v (6 cells)

The rover will have to be able to move if someone wants to play with it and automatically charge when returned home.

This is an engineering class at UC Merced, so it is excepted, but time frame is short.

 

[aEx155]

Here's my quick snippet of info; don't have much time for a detailed response now but will later on in the week:

http://en.wikipedia.org/wiki/Inductive_charging