I'm an embedded s/w guy, but I'm able to do low voltage circuits without too much trouble. So I will try to ask this question on high voltages!
I've got a power supply running at 1 to 15 kV. It runs constant voltage, always on. The power supply provides a charge for ejecting water droplets. See this video to see what I'm talking about.
I need to control the charge (on or off) for the electrode. What approaches might work?
Spec wise: 1-15 kV, kHz-level frequency for switching.
Here's what I got brain storming wise:
- Control from the low voltage side. Don't apply an AC signal to the transformer. (But currently using off the shelf PSU.)
- IGBT. They're on the expensive side the higher max rating. Also seem to be focused on high current applications. And apparently they can be slow (haven't gotten very deep with the specs).
- Cascode. I saw some circuits and papers that seemed to suggest I could use this approach, but there is a lot I don't understand.
- Some kind of virtual ground method? Say 10 kV and 9 kV. (AC coupled control signal?)
This is a beyond my abilities. Some thoughts would be very useful.