High-voltage bench power supply

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I finally got around to documenting this HV bench supply that I designed and built a while ago...

Details, schematics, etc. are here:


Newbie question: I'm considering building this, and my B+ transformer on-hand is good for 360V@160ma.

Can I use less pass tubes? I'm assuming that these are paralleled to allow for Pete's 500ma current requirement.

I have a handful of Chinese 6L6GC's. If I can reduce the number of tubes to say 2 or 3, does anything else need tweaking?
I got a commercial one that goes to 1000VDC @ 200MA. Measures volts, current and computes watts. It's got a digital display. Very kool but it kicks out the overload breaker or frys the voltage control pot (5K) randomly. When I get around to it I'll start with replaceing all the caps otherwise it's got too many sand state components for my meager brain. I'll have to get it fixed. I hope it's KVA rated. Like 500VDC at 400MA? That would be nice. It's a piece of medical equipment used in DNA testing or research. I have not been able to find a scheme.
Someone brought up thyratrons in another thread. You should make one with some -- who needs pass tubes except for ripple attenuation? Much better efficiency with switching. And hey, if you still need low ripple, you could add a hum bucker to cheat on the inductors and capacitors needed to kill the hum.

Any of you lucky enough to own one of these bad boys?


Because I do =)

Why is it that no one has used something like an 811A as a pass tube? The rest of the regulator could easily be sand...
Splendid! About the only information you didn't give was its mass. Lots, I imagine.

UH, if you have to ask, you can't lift it!

Any of you lucky enough to own one of these bad boys?

I has a big tube with battery cables hanging out of the bottom. It was about 2 feet tall and I couldn't even light the heater without smoking a transformer, so it and a whole pickup truck full of thyratrons were sold for $200.

I'd love to see someone sell a PCB for one that tops out around 550V. My Heath is only good to 400V.

I have 3 different 400 volt supplies. Those were limiting my fun so I found a Fluke 407D for cheap on Ebay. There are rated for 555 volts at 300 Ma. I routinely bury the meter needle and it hasn't blown up yet. It still has the original tubes and caps in it. After about 4 years, I wanted more juice, so...

but I just got a HP6448B power supply so I guess I'm lucky I wont' be staging another project with it yet

Yeah, thats the ticket. Rated for 600 volts at 1.5 amps, mine goes to 650 volts and 1.7 amps. I have not yet needed more power than this thing puts out. In fact I think my wall outlet is now the limiting factor since I have blown the breaker twice. I have used this guy to squeeze 200 WPC out of Petes red board. Photo shows the HP warming up some 6KD6's. 500 volts at 1.6 AMPS! Thats 800 watts going into the board. A little over 400 watts are comming out!

Just for fun I connected the power supply up to a dead 6AX4......Guess who won that battle.


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I got one of those ISCO Electrophoresis power supplys off epay for cheap.

I bought two electrophoresis supplies from sellers that claimed they worked. I couldn't get anything out of either one. There stashed in the warehouse somewhere, likely to be scrapped the next time I get over there.

Early on I used a variac, a 480 volt industrial transformer, a bridge rectifier, and a big cap to make a 0 to 650 volt 10 amp power supply. it was unregulated, but quite useful. The very large transformers that I used made the whole unit weigh about 100 pounds, so it wound up in the warehouse.
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.