Hi Guys!
I want to build a capacitor leakage tester/ checker instead of buying something expensive.
I was thinking of using my variac, followed by a voltage doubler to reach about 700V DC.
I'm open for ideas and if any one has a better layout, please share it with me.
What you have in mind is very similar to what I use to reform capacitors, should suit your needs with your voltage doubler instead of the 1:4 step up transformer needed here, jpg attached.
We are 120 mains, so this plugs into variac, a 1 amp wacky circuit breaker with a long red button from an old '60's TV set or something, transformer is 120V --> 480V step up, with center tap.
Bridge rectifier from the 480V, and a pair of 10uF/450V filter caps in series, center point of caps to center tap of transformer, the same voltage range output as what you have in mind.
The implementation is drawn out on the jpg: A precise 1K resistor from positive for monitoring current, 1V = 1 mA. 1mV = 1 uA. Those test sockets take meter probes snugly, just plug in the meter leads and leave it there to monitor current.
After that, is a 47K / 10 watt green ceramic, shown peeking out at the bottom of the photo, it is ballast for reforming caps so you can leave them reform overnight, unattended. Last, test jacks to monitor the cap voltage with a second meter, if you want. The buss wires sticking out is where you actually connect the cap with alligator test leads.
Just a simple "I need something in 20 minutes" project, that I still use.
Gene