I picked up a Duracell wireless charger at a garage sale. Model CP-PPS. Also known as MyGrid. Jentec AH 1815-B Rated 15V at 1A.
It's NOT inductive. Has alternating metal stripes that supply power to contacts on the device adapter.
I have the adapter for the ipad, but no ipad.
Thought I'd reverse engineer it to see if I could do anything useful.
It puts out a square wave from 1V to 3V with a period of about
2milliseconds with a source impedance around 10K.If you put a resistive load on it, it just drags down the square wave.
If you put a diode in series with a load of less than 10K, It powers up and puts out 15V with a narrow periodic sense pulse to near ground.
So far, so good.
Problem is that most devices need 5V. Not sure why they used
15V.I was gonna put a zener in series and charge my PDA, until I did the math and decided I'd need to dissipate 10Watts.
The ipad adapter doesn't look like it has any place big enough for a switching regulator. I really don't want to tear it apart to see.
Anybody got insight into how this thing works?
Thanks, mike