900V power supply. Part 1.

We need a high voltage power supply. I am going to use DC/DC 12 to 300V boost converter schematic based on UC3843.

Fig. 1. UC3843 based 12 to 300V DC/DC up-converter.

To achieve even higher voltages I am going to use 3 identical secondary coils instead of one. This would give us 3 x 300 = 900V. Although it is less than 1200V used in original design I think we can start with this voltage. Special bobbin has been designed and 3D printed to incorporate 3 secondary coils. Coils are separated to avoid insulation breakdown.

Fig. 2. 3D-printed bobbin for EFD25.

Each secondary coil should be a accompanied by separate rectifier diode, RC snubber and output capacitors of course. The PCB has been designed in a way that all these elements are placed together inside a dashed rectangular area. So I don't have to order additional PCB from the factory, I can simply cut it from those PCBs that I already have.