I needed a variable 0 to 50KV high voltage power supply for my high voltage experiments that wouldn't break the bank, so I built my own.
With just a few parts from old microwave ovens, TV sets, and an oil burner, you can build an affordable instrument for whatever you wish to snap,crackle, or pop!
The key component is the voltage multiplier, which I covered in the High Voltage Multiplier instructable. Build it first, then drop it into this project for a variable output.
Step 1: Theory of Operation
The diagram shows the supply in the de-energized condition and the case closed.
Mains voltage is applied to the power supply thru a 120 VAC Panel connector. With the case closed, current passes through a 5 Amp fuse, F1 and through the case safety switch, S1 causing the Ready indicator, I1 to light when the power switch S2 is placed in the ON position to energize the supply.
At this time, the power supply is NOT ON but in a state of readiness to enegize the high voltage stage.
When pushbutton S3 is pressed, relay K1 energizes and remains energized after S3 is released.
Current passes through Variac, VT1 which adjusts the input voltage to the OBT. The OBT steps up the input voltage to a maximum of 6,000 VAC. The output of the OBT is fed to the high voltage multiplier, HVM where it is multiplied to 51,000 VDC output.
To de-energize the supply, place S2 in the OFF position. K1 will de-energize and remove power from the OBT and HVM and all indicators will extinguish.
The case safety switch and the power contactor are not necessary for this supply to work. I thought the ability to power on and off by using a pushbutton was cool. Thats all. The second schematic shows them removed.