Have you ever felt the need for a 0-350V lab power supply? If so then this might be the right thing for you:
http://hpm-elektronik.de/ng350-0400-netzteil.htmThe description is in German but the circuit is self explanatory.
As I play around with tubes sometimes I have felt that need several times, but never had the time or the parts to build one. Now over the easter weekend I found a box of nixie tubes while clearing out some old crap. I wanted to test them if they still worked but there was that old problem again: Where to get 150V DC at short notice?
So back in the box the nixies went again.
On easter sunday morning I visited a local fleamarket and picked up an old isolation transformer in a nice case for a couple of Euros. I didn't need it as such as I allready have one but I figured the transformer and the case might be the ideal base for a HV lab power supply.
I also found the link above and decided to use that circuit instead of making up my own. I had to change it a little to suit my needs and the parts I had better but it is mostly unchanged.
The old isolation transformer turned out to be quite ideal for a PSU of 350V at 250mA. The case is a bit small but I managed to shoehorn everything into it.
It's adjustable from 0-350V, short circuit proof and provides CV and CC mode.
The chassis is made of FR4 PCB pieces soldered together. I like using PCB material for cases, it's cheap and very easy to work with but still very strong. The chassis holds the electronic and slides into the case that I've got from the isolation transformer.
I've tried something else for the frontpanel this time. It's simple A4 printer paper stuck to the frontpanel and then covered with a sheet of laminating foil. The laminating foil can simply be ironed onto the paper. It protects the paper and gives it quite a nice finish. This works rather well.
I decided to use analog meters for this PSU, it would have been hard to fit digital panelmeters into this case and I had two identical 100µA meters to hand anyway. The scales are custom made to my needs, just a bit of Photoshop magic.
Now, where did I put those nixie tubes?