OT: replacement bench PSU

[rjs]

My trusty homemade bench variable PSU has expired. It was a 1.5 - 30 V

0- 1 A (DC) unit that had given many years of service and I'm inclined to replace rather than repair.

What experience does anyone have of buying such items? A Google has revealed many SERIOUSLY expensive (but desirable!) lab units that far exceed the depths of all my pockets and some that are less frightening:.

Powercom offers a fairly hefty 0-30V 0-3A model here:

well as a couple of lower voltage units.

Henrys has the P005 series here:

they seem a little crude when compared with Powercom's units. And expensive if you look at the P005B

There is, of course, eBay but . . . .

Any thoughts, etc gratefully received

Richard

[Ian Stirling]

?

[The Natural Philosopher]

Ebay is your friend. These do not come cheap, but there they are cheapER.

[Owain]

Which bits of it have expired? It might be worth saving the (expensive) case, transformer, meters, etc and replacing the control PCB with some nice new electronics.

Owain

[rjs]

I should have said that it is now an opportunity to increase the current o/p of the unit. Sorry

Richard

[rjs]

You are absolutely right Owain. But, as it is a home brew unit that I have put up with for many years - especially the puny 1 A max current - and now have the ability to spend a bit of money on something more useful I though I would!

Actually the case is an ali box and the meters are cheap moving coil jobs. The, albeit torroidal, transformer is not fantastic, etc!

Richard

[The Natural Philosopher]

Shurely you mean a rasin to increase the currant capacity? hic.

[rjs]

Shertainly, Mish Monneypenny!

[meow2222]

There is one other option. If you want a simple high current 24v or 36v psu, 2 or 3 computer psus in series with the earth disconnected from one and a dummy 12v lightbulb load on each 5v line, plus the power on wire connected to ground will do that. Instead of hard wiring them together, bring the various Vs out to a set of 4mm sockets and you can have:

1.7v 3.3v 5v 7v 12v 13.7 15.3v 17v 19v 24v 27.7v 29v 31v 36v

some at 20 or 30A, some at 2 or 3A. Add a couple of diodes as droppers and you get even more V options. Add a linear reg board and you can get any v you want.

NT

[rjs]

Thanks

Yes, I did come across a 'how I made a bench psu from an ATX poswer supply' type pages, but I do want variable current limiting

Richard

[meow2222]

I assumed you'd add your own tronics to the end to give whatever features you want.

NT

[The Natural Philosopher]

net you lots of PSU's. About £50 for a new one..and less for second hand

If the URL is folded just search on .. (lab PSU, Bench PSU, bench power supply, lab power supply)

[rjs]

Yep. Been watching a couple whilst running this thread. Interesting that they both seem to be CPC stock items!!

Richard

[rjs]

The Hyelec 3003 is claimed to be up to 30V and 10A and only 4 months old howver I can find no mention of a 3003 on the Hyelec site with that rating and the seller cannot find a model number on the unit. Hmmm!