High Voltage Variable Bench Power Supplies?

[Tim]

I have dug out the HT PSU with the three 6BW6 in parallel and taken some pics of it and the reverse engineered circuit. Is it OK to post them on this thread or shall I start another?

[woodchips]

I have bought all sorts of high voltage PSUs to test valves, but 1000V at 1A is just too frightening to fix.

Then had some Roband Varex 60/1 (60V at 1A twice) PSUs, got a manual and found that you can both series and parallel these. Connected 2 in series, so maximum of 240V, the dual sections in each can be connected in series, and powered on. I was astonished, the full current limiting was available and working. From memory these PSUs can be stacked up to 500V maximum.

Ended up buying any Roband PSU that came up for sale, have enough now, but the idea that it will allow a misconnection of heater across HT is really nice. The variable voltage is easy, it is the current limiting to tens of milliamps that is unusual.

[Andrew B]

I have an old unit given to me by a chap who used to work at Hinckley point

Strange coincidence, I have the Farnell 300v unit given to me by a chap that worked at the BNFL research facility at Birchwood, Warrington. Labelled up for testing "Ignitrons/Sprytrons"

[GrimJosef]

Originally Posted by woodchips

... but 1000V at 1A is just too frightening to fix ...

A few tens of milliamps can shock you to death, as can a few tens of joules stored in that capacitor you charged from a 1mA supply. The trick is to keep the resistance of any circuit in which you play a part high (preferably tending towards infinite) . 1000V and 1A can start a decent fire pretty quickly though.

Cheers,

GJ

[daviddeakin]

Originally Posted by Chris55000

I have taken delivery of a "Kquaiqu" 0–300 V unit
These are, of course, a switch–mode

Is that an electrophoresis power supply?

Building a DIY adjustable bench supply up to 300V 100mA is easy peasy. Above that and you start having to use your brain.

[Diabolical Artificer]

For a 0 - 450v 500mA supply see Pete Millet's DIY supply that uses 5 807's - http://www.pmillett.com/HV_bench_supply.htm

Re pass devices in HV supplies I've read that BJT's are better than switching mosfets but now you can get linear mosfets though they aint cheap - https://www.microsemi.com/product-di...fet/732-linear IXYS do some - https://www.digikey.co.uk/en/product...ear-l2-mosfets which looking back through the thread is what Thatvalveguy used in his PSU post #7.

Andy.

[matherp]

I've got one of these. Seems to work OK and output seems stable. I've wired in one of the cheap voltmeter displays so it is easy to set and monitor the output.
Of course like anything high voltage needs to be treated with respect and with the usual precautions