I am trying to make an high voltage arc generator which is approximately 2 kV output. Here I can easily drive this circuit with 19 volts (laptop battery). Just like in the circuit bellow, I connected negative terminal of BAT1 to negative terminal of 19 V battery. The transformer that I designed is for 300 V input with a turn ratio of 1:7. My first try with a duty cycle of 70% I observed small arcs at the output of transformer. Now I want to try to connect 300 V DC instead of 19 V DC. But I am not sure about connecting negative terminals of BAT1 and 300 V together.
simulate this circuit – Schematic created using CircuitLab
1) How can I improve this circuit to use it with high voltages such as 300 V DC which is rectified from the mains?
2) If I connect negative of 19 volt and BAT1 separately then mosfet doesn't go off I didn't understand the reason. When connecting to 300 V how should I connect negative terminals? Or should I use earthed cable?
U2 is TLP250.