Benchtop PS From Computer

[ricki]

Hope someone may be able to help me.
Dscn2119sm.jpg
About 20years ago, I built this benchtop PS to run-in motors, power my tire lathe, etc, from an old 200W computer power supply. I'm not smart enough to have come up with that myself, so had to have instructions from the 'Net somewhere. I can not find those plans now, but perhaps one of you may know of it :?: I have a small LT1084 regulator design from www.SlotSide.com on file, and perhaps that was somehow part of the job. That Forum seems to be down.

ps - image insert failed, attachment seemed to work.

Mike.

[MrAdept]

Hi Ricki,
That looks very cool!


Mark

[ricki]

[MrAdept]

Hi Mike,

These seem to be going down well here with a few members. This would give you up to 10A at your voltage range.
http://www.amazon.com/Precision-Variabl ... S1XFNSJSP4
I think there is one company making and then every man and his dog is putting his own name on them! If you search ebay there are loads. I have one that is similar but 5A.

Datasheet for the LT1084 is here - http://www.linear.com/docs/3741
The 1084 is the 5A variant. Page 2 shows the pinout and page 16 shows a 1.2V to 15V Adjustible regulator diagram. I would pick 25V caps for C1 and C2, e.g. 10uF 25V and 100uF 25V (don't forget to connect them the correct way if you are using electrolytics.).

Connected to a PC power supply will give you something like 1.2 to 11V or so.

The ATX PC power supplies have 12, 5 and 3.3V on them and also have no mains power switch. You will need to connect a switch between PS_ON# and COM in order to turn the power supply on and off. (or just put a wire and turn on and off by plugging in the AC cable.)
Here for the ATX main connector pin diagram
http://www.smpspowersupply.com/connectors-pinouts.html

Don't forget you will need a heatsink of some kind for the LT1084. This type of regulator tends to get quite hot when you draw a lot of current through it.

Mark

[RichD]

Here is an article: http://www.wikihow.com/Convert-a-Comput ... wer-Supply

[ricki]

Thank You Rich -
Not a familiar one to me, but certainly fills in some missing details.

[ricki]