My Bench Psu!, I need to add a post to my post counter.

I finished the thing this morning.
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Things I learned;
This is a COMPAQ PS2013 ATX PSU
*The green PWR_OK is not connected to black gnd, but to the white cable... labelled "aux 9".
*The PS2013 does not work properly without a load resistor. Some PSU designs do, this doesent.

Sincerely,
Hamlet

OH MY GOSH!!

I've built one myself, and had the PWR_OK going to an LED then to COMM, to give a visual indication..but it never starts up - that would be why

Well, back to the guts to fix it

Oh, and im loving the yellow colour scheme Are those 2mm connectors by any chance?

Those two on the top are 4mm 'banana' jacks.

Hamlet

ah ok, thanks they looked smaller in the pic

What is the item to the rear of the PSU covered in what looks like green plastic and connected by a couple of spade connectors?

wirewound resistor

Is the wire wound resistor the Load Resistor?

heh heh heh ... coooolll

man , that looks like it would fit right in on the old original "flash gordon" series !

Good show. I mean the supply.

It never quite sat well with me just making by-heat with a load resistor though. (it's a personal thing, not a 'poor design' thing) So far I've found that either just a 12V puter fan or a small incandescent automotive bulb (bayonet clearence light bulbs will fit in the old school "6.3V" jewel panel indicators) presented enough for a load.

I know its not efficient, the resistor I mean. But I had it lying in my drawer. It draws roughly 600mA (out of the 20A allowed combined on both 3.3V and 5V). All of the stuff I used on it are salvaged (old USSR = big switch and resistor power) - so it was a sort of for looks project. A fan would have been a better alternative.
"Flash Gordon" indeed.

And you have done very well!

What have you used to engrave the Al plate/dial? To complete the look I think you need a bakelite look power cable connector and cotton/silk covered mains cord. They used to have these on old irons & kettles. Recently I have seen a bakelite connector on a rice cooker but not the cable.

Only if there was a way to give some retro look to the cooling fan

I used a dremel with a 2mm diamond tip. I have some of those cotton wound cables, but they are no go in this case. I like the plug in and out of mains made easy, grounded besides. I have some fans from the 70's or so, but they are huge and noisy and so on. No go as well.

Regards,
Hamlet

That looks pretty cool, nice job.

Very nice looking! Did you paint it, yourself, or did it come like that? What did you salvage the rotary switch from? I have three extra compy PSU's lying around, and this post finally got me motivated to make a bench PSU out of one of em, although it won't look anywhere near so nice.

I think there may be one oversight, though. You appear to have only one output jack. That would make the -5V and -12V selections into redundant, low amperage voltage sources with the leads switched, for most intents and purposes.

If that's the case, I have another suggestion while you're in there amending things... move the resistor to the middle of the case so you can use it for a carrying handle.

""Flash Gordon" indeed."

is that said with a dr. smith infliction ?

I ripped the switch from an old hobby-photo purpose timed relay. I have seen this switch in many USSR devices, seems to be a standard. A neat design because the switches can be theoretically stacked to infinity.


This is the belly of the single switch I used. The switch from the relay. I wonder how many amperes can I draw before the contacts start melting.


This shows the switches stacked. This is from some oddball thermometer.

I painted the box myself.
I don't mind the low-amperage.
The resistor is wound onto a ceramic tube, not a good idea to use it as a handle.

Hamlet

there were a couple of companies in the US that manufactured a line of "roll your own switches and pots" .
you could build up just about any thing you needed ... they were designed for use in the consumer repair industry .
one company used a blue/yellow box ... CRC or IRC comes to mind .
the mallory company (caps/rf stuff/ignition) had a line of ceramic rf deck switches .

I think johnson used to make some ceramic switches too. Definitely made ceramic tube sockets, at least.

yep , they made some stuff .

eimac was another outfit .

I'll bet!! ARRRH! Sizzle me timbers, matey!

Nice work.

Not in full amperes if this is a representative of the type of switch:

http://www.alltronics.com/cgi-bin/category.cgi?item=24B027

I like it the only thing I would do is make a load resistor that I can set my coffee mug on. Love the yellow.

i like this idea. Maybe you could salvage/design a small hotplate that could serve as the load resistor? Not that I'm knockin the one you've got--looks great.

My own ATX power supply is completed, thanks to your inspiration, here. As for the load resistor - I not only found out that mine did not require one, but I discovered why.

I did some multimeter probing using various load resistors on the 5V line and a 12 amp load on the 12V lines, and the load resistor made no difference. The 12V output under 12 amp load was always 11.52-11.56V, no matter what was on the 5V line. When 12V line was left open circuit, the voltage was 13.06V, regardless of what I put on the 5V line.

After all this mucking around, I probed the 5V line to measure actual resistance of all the smaller load resistors I was adding in parallel. And something was off. The measured resistance between power and ground is 8 ohms, even without an extra load resistor! I found an 8 ohm power resistor between 5V and ground, and I found a 10 ohm power resistor between 3.3v and ground in my supply.

So anyone doing this at home, check resistance between +5 and ground before you start adding extra load! It may have a resistive load built in! Mine is a cheapie Rosewill AP-400X from Newegg.

Not in full amperes if this is a representative of the type of switch:

http://www.alltronics.com/cgi-bin/category.cgi?item=24B027

The switch Hamlet is using has contacts that are considerably more robust. It should be good for several amps without any problems, especially if it is not switched under load.