08-06-2013, 05:29 PM
Managed to get back on it for a couple of hours. New Rx coil with 72 turns and 0.22uFd cap produced poor results on 21KHz. Swapped the large Tx coil for the old 12 turn one and increased the tuning cap to 3 x 0.33 uFd. This is now running at 41KHz, the caps run tepid, the fets are cooler while the coil is quite warm. I've just noticed that the PSU volts are being dragged down so that everything is now running on 9V. The O/P on the old 34 turn coil with 0.22uFd and a single rect diode and 47uFd is giving 12V into a 50 ohm load.
I tried another PSU 19V (laptop) ouch burnt my finger on the 12V stab, pulled the plug immediately. I need to dig out a 12V PSU or find one at the flea market so that I don't need the 7812 etc.
Mike
I tried another PSU 19V (laptop) ouch burnt my finger on the 12V stab, pulled the plug immediately. I need to dig out a 12V PSU or find one at the flea market so that I don't need the 7812 etc.
Mike
