1200V PSU

[ppppenguin]

I'm sorting out an obscure corner of my storage and found a PSU like this one: https://www.netbid.com/en/auctions/detai...se-System/

Odd that I should have mentioned HT supplies for photomultipliers earlier today in another thread as this looks like it could fulfil that role. Though it may not be smoothed and regulated well enough. The link suggests that it might have been used for chromatography "Elektrophorese". Searching on LKB they certainly made stuff for chemistry labs. It may have come out a biology lab when I was living in Oxford.

If I have a spare moment I'll take a look inside and run it up if it looks OK. No particular use for it at the moment but far too good to get rid of.

1200V and 50mA should inflict a nice belt

[Mike Watterson]

Home made dye laser PSU?
Allegedly some brightly coloured liquids in the supermarket have suitable dyes and people make lasers with them?

A really scary flash gun? Big Xenon tube and lots of really big caps.

It's certainly rather niche as it's not enough power for the scarier valve RF PAs. I forget what a twit AKA TWT uses, though I repaired the multiplier on an install using some. Maybe -40kV? You weren't allowed to visit the site on your own.

[ppppenguin]

I've just run it up. Used a lamp limiter just in case but it came up nicely. Meters are more or less spot on. At 500V output into 50K, I unloaded it and the output rose to 550V. So it's clearly not regulated. I haven't checked if it's regulated against mains variations but I suspect not.

Opened it up and it's very simple. Switched tapped transformer. A couple of chunky 4uF Rifa (paper?) caps in series and not much else.

[Mike Watterson]

What sort of power?
Hard to tell from the photo. I know you said 50mA @ 1200V = 60W, but that might be a rectifier / smoothing limitation. Maybe it would do as one of the three supplies needed for a valve tester. I'd think it less than an ideal solution for testing capacitor leakage as the Flash gun circuit could have a bunch of 0.5uF caps and UF diodes to step up the 200V to 600V (depending on model) instead of the single UF diode in them.

[ppppenguin]

50mA max hence 60W as you said. I don't think the transformer is good for any more than that. With only 4uF smoothing and 50mA rating there will be a LOT of hum on the output.

I was right about where it came from. I found a label on the bottom saying Dunn School of Pathology. That's where my ex-wife worked when we were married and living in Oxford. They routinely slung out stuff.