I made a simple wireless power transfer system based on LTC4120 and a simple oscillator, described in the datasheet.
LTC4120 as battery charger works very good, when powered by a Lab supply at 15V.
The simple oscillator itself works well, with 30V p-p sinewave.
For first coupling, I didn't use the DHC control, so there is only a series LC resonator, rectifier and input capacitor on the system. Well, when I couple the receiver with the trasmitter, charge LED goes ON without a battery connected and this is strange (the LED should be off without a battery), but anyway if I connect a battery the LED is still ON but no charging at all.
I can see the input voltage goes from 12 to 25V moving down and up the receiver but no charging at all. How can be possible??
With a power supply charges well and with a voltage rectified from the resonator doesn't charge, it's a mistery for me now.