I recently stripped a microwave of its transformer and I was looking forward to playing around with it. I didn't want to plug it directly into the wallsocket so I decided to design a circuit that can run on my DC power supply. Here is my circuit:
I created a monostable oscillator circuit for my clock like the one shown here: and I am using it to create a square wave across the transformer. In the schematic I have a 10K ohm resistor at the end of the transformer but in real life I have a spark gap (couldn't find one in the builder). Now as I raise the input voltage (at the peak of the square wave) I don't see anything until the current rises past around 0.03A and which point I can get sparks! The output voltage is somewhere around 30V unloaded which will drop after a load but I don't really care about this as I am using a spark gap instead of a real load. The problem is, when I raise the input voltage to around 30V with extra resistors behind it so that the current is below the 0.1A mark at which point my transistor explodes, I still only get a voltage difference of 30V at the output. Why does this happen? Do I need more current to get a higher output voltage?