I am looking for a high side switch (20mA, 400V) circuit for half wave rectified mains, which I would be able to control with 5V GPUO.
I am building a Nixie clock with 74141 drivers and a microcontroller. The Nixie tubes are powered from half wave rectified 230V 50Hz mains. I would like to turn off the Nixie tubes completely for 400ms (i. e. blink them.) It seems to me that 74141 drivers don't offer any way to turn off Nixies completely (all digits at once,) so I thought about adding a high side transistor switch, controlled by 5V GPIO.
What's the best switch for this application? PNP or PMOS or maybe something different? Thyristor? (Requirements are: 20mA max, 400V.)
I can think of two solutions. I think with PMOS there is a problem with keeping Vgs within limits all the way through half of sinewave, because of voltage variation.