HV DCAC neon lamp driver from nixie supply-arduino controller

I've been working on a nixie clock based on https://www.instructables.com/Arduino-4-Tube-Multiplexed-Nixie-Clock/ forever. The neon lamps are powered with DC, which bothers me because I want both 'trodes glowin'! This resonant transformer is excited by a simple pulse from the arduino. This can easily be added to the source code by replacing "delay(p)" with a simple new function that switches the lamp circuit on the order of microseconds, rather than simply doing nothing for 2ms. Originally had difficulty limiting power loss in the primary trying to limit current to safe levels. It took some time to realized that I was actually only concerned about stray DC, particularly in the event of transistor failure. A parallel circuit with less than 1/4W of DC, but low impedance at the resonant frequency was the solution... Or so I thought. It only work about 2ms before the capacitor needs to discharge!

published 4 years ago