Flyback Driver

The Lightning Stalker, Sat Jun 18 2022, 06:11PM

I had some bipolar power transistors lying around doing nothing so I decided to make a flyback driver that doesn't use MOSFETs for a change. (Maybe MOSFET are a little difficult to find.) It uses Sziklai pair which is a bit slow so there are some turn-on losses. Darlington isn't much better and neither is anything else apparently so it was taking a while and Sziklai pair was good enough for me.

To fix the heating I made a variable duty cycle with the 555 and a diode. The pot varies both frequency and duty cycle and it works well enough. It has a variable arc. It was good to see a flyback again after a few years. The snubber idea came from a switch mode power supply and then I see some other people using it. It seems the diode is finding me again.