Protecting other circuits from Geiger power supply

I'm designing a Geiger counter power supply that boosts 3.3 V to 500 V.

The circuit is a basic voltage booster.

3.3 V power line is directly connected to inductor where high voltage is generated. How can i protect the 3.3 V line = other devices connected to it, from high voltage transients generated in the inductor? Or is this even a issue?

My initial thoughts were using TVS diode before the voltage booster.

• Why start with 3.3 V? Is that really the highest you have available? Aug 7, 2023 at 13:57
• 5v is available too, but 3.3v is already enough to make the circuit work. Aug 7, 2023 at 14:36
• What Finbarr's getting at is, 500:3.3 = 151.515 times as much voltage. So to get 1mA out at 500V, 151.515mA would be drawn from 3.3V (ignoring about 20% loss.) At 5V this current drops to 100mA plus losses - so higher voltages are easier to boost. Aug 7, 2023 at 14:39
• If your Geiger tube is drawing 1 mA, your health is in danger. Aug 7, 2023 at 14:45
• You don't need 1mA with a Geiger tube, they need maybe 100uA when there's a pulse, average current is much less. There are circuits online using 3V (see techlib.com/science/geiger.html). Aug 7, 2023 at 14:49