I want to increase the output of a function generator (0.5 V Ac) to something in the order of >2000 V.
I have an open circuit, so there is no concern about the current.
You guys have any idea how can I do it? Or where can I find a high voltage amplifier?
I have some 2000V transistors (100mA) but they are real hard to find. Most of those transistors are out of produciton.
Tubes (valve) could do the job....also hard to find.
You could make a 200V amp and auto-transformer up to 2000 volts. I have done that. The transformer will be a problem.
My approach would be to use an off-the-shelf amplifier to amplify the signal up to an intermediate voltage (say 20-50V ?) and then use a step-up transformer to go from there to 2000V. A LOPT from an old TV or monitor might do the trick.
Edit: Ronsimpson's post crossed with mine. I see we're thinking along the same lines!
High voltage transformers are potted. (filled with an insulator) They are potted under a vacuum so no air pockets can happen. Some insulators are soft and can be removed with a knife and some are hard.
A TV flyback might have only one diode. Many CRT monitors have transformers that have 5 to 7 secondarys with a diode between each winding.
You probably could get a standard HV power transformer, such as from a microwave, to operate up to 1500Hz. It might be somewhat lossy but that shouldn't be a big problem if no significant output current is required.
Good idea Alec_T about amplifying to an intermediate voltage and then use a transformer to get to the final voltage. I Google and found a couple of sites for function generator amplifier and high voltage transformer.
I have seen some older TVs with the diodes on the PCB and some flybacks with the diodes in a tube coming out of the potting that have a screw top so you can replace them.
maybe have a look around and see what you can find.
Andy
A TV flyback is designed for 15khz. You will probably fine it wants to resonate at 3, 5 or 7x that frequency.
If there are diodes around the flyback on the PCB they are for the sub-1k voltages. 27Kv is never on the PCB.