/diy/ - Do It Yourself

>>2504484
Why isn't my IGBT chopper, chopping?
Switching circuit is typical 555 timer, putting out a square wave with 50% duty cycle at the 12 volts Vcc from a battery, circuit frequency is about 8 kHz, output current about 250 mA
The IGBT model is IHW40N120R5, breakdown voltage of 1200V, max collector current 40A, gate emitter threshold voltage is 5.1-6.4 V at 1.0 mA collector current. Happy to provide more info
I'm not sure what I'm doing wrong here, to my knowledge the common emitter configuration allows for voltage-amplified switching, however when I connect my oscilloscope leads as shown I just see a low voltage DC signal, even at 1000V (I assume some sort of leakage current?)
Why am I not seeing the load switching on my oscilloscope?
>What I'm trying to do
This is a test for a beefed up system, I happened to have some 1200v IGBTs laying around and wanted to make sure I knew what I was doing before ordering more. My ultimate goal is to switch a voltage of about 3000-5000V across a load with an equivalent resistance of about 500,000 Ohms (about 5-6 mA expected current) at a frequency of 5-10 kHz. I say expected because the load is actually an electron beam which I need to switch at kHz frequencies for research reasons
I'd probably want to work my way up in current but max would be a few hundred milliamps.
I am thinking about switching to using high-voltage MOSFETS but IGBTs at those voltages would be cheaper and more readily available.