my main problem is the power supply of the rotation part
i use a PC fan 12V dc
i tried to build an air-core transformer
100 wounds on primary coil , 400 wounds on secondary coil ,12V dc supply voltage and 200 Khz on the gate of mosfet transistor (IRF640)
on secondary coil I get about 25vdc (after the diode and the capacitor)
but if I connect a simple load (just one red led 20 Milli AM ), the output voltage become 2.2V dc
so I have low power on the output.
what I have to do?