Inductive power transfer + sensing resistance?

First, there are a variety of popular circuit types to use to generate AC from DC, also called inverting. My favorite and probably the best for your application, will be a resonant converter, which will use a pic signal to trigger one of two transistors which are both connected to the primary inductor and a capacitor connected to ground in series. It's a sort of simple push-pull setup, but more importantly, set the frequency that the system is pulled or pushed to the natural resonant frequency = (1/sqrt(L*C)) Secondly, for transmitting the information via IR, it might be better to use an opto-coupler if your 'moving item' can still be wired. You could also try some form of charge signal modulation to send communication signals between devices on top of the power wave. Good luck

Thanks for the response. Would you happen to have a schematic for the push-pull setup? Also, to generate the resonant frequency could I just toggle the pin repeatedly or use a PWM signal?

What would be an ideal frequency (in hz?) My PIC has a 20mhz XTAL so I guess that would put a cap on a full wave to 10mhz if the PIC is doing nothing else while modulating. Does the frequency make a difference to anything other than the efficiency?

The moving element certainly can be wired, just not to any fixed parts.

An optocoupler would definitely be the ideal way to go except that there is not a straight physical path between the detector housing and the LED housing, rather a curved channel for the wires to pass through and the gap between detector and LED is 1.5"W with .75" vertical clearance.

You can obtain an AC signal with a PIC using the PWM module to create a square wave signal and then filtering it LO-PASS. The best results are obtained with 50% duty cycles (less hi armonics).

inductivepowertransfer.com inductive power transfer

inductivepowertransfer.com inductive power transfer