Author Topic: transmit electricity over plastic (Read 3432 times)

IceMetal · « **on:** February 02, 2009, 10:50:05 AM »

Hi I'm trying to build a battery charger for a robot. I want the robot to charge the battery when is on top of the plastic base, I had tryed with magnets and it doesnt work, I was trying to hack one of thouse windows alarm sensor to transmit electricity, and it cant be done that way, any ideas maybe with a coil? I can transmit current to charge the battery on the robot without using metal contacts. thank you

Joesavage1 · « **Reply #1 on:** February 02, 2009, 11:56:07 AM »

have you tried with a stroger electro magnet or somthing, maybe a reed switch could come in handy.

Joe

paulstreats · « **Reply #2 on:** February 02, 2009, 12:04:08 PM »

You need to do it with 2 coils. Look at electric toothbrushes, the base has a plastic bit with a thin coil inside, the toothbrush itself has a slot on the bottom where it fits over the plastic of the base, this has a large coil that the smaller one slots into (similar in set up to a tesla coil where 1 coil slots into another). Using this system, you can transfer through plastic efficiently.

You can also do it without slotting the small coil into the larger one but its not efficient.
Also you will need to pulse the electicity on the base in order for it to transfer.