This might help. A while back I struck a surplus gold mine with a cheaply obtained bunch of Advance Hivolt cascade multiplier power supplies. These are used in ion implanters (among other things) to deliver 100-200 kV power in the mA range. The driver is a pulse circuit (20 kHz nominal if I remember correctly) using a PWM controller (clock) driving an array of IGBTs. The output (about 800 volts) goes to a ferrite core transformer which steps the voltage up to 10-0-10 kV (20 kV CT). The transformer then drives a set of full wave multiplier disks. 5 disks = 100 kV, etc.
My problem is that the input is a few kW 3 phase so the driver as is doesn't work for me. My intermediate solution is to drive the cascade with two 12 kV transformers at 60 Hz. I get full voltage output to 120 kV but the current is much lower at the reduced drive freq. Great for charging my low value cap discharge pulse devices.
At some point I will make a medium power driver using the IGBTs and a less beefy PWM.
I did obtain a full set of schematics but they are probably fairly useless w/o the hardware. Also there's lots of safety and regulation features built in that complicate the design.
Some more relevant info can be found on Toshiba's web site under the data sheets for their IGBTs. There are sample circuits, etc.
Steve
Created on Wednesday, February 28, 2001 10:53 PM EDT by Steve Hansen