i'm looking to buy a vintage power supply much like this one for sale on eBay, for a project i have in mind in the future
https://forum.allaboutcircuits.com/forums/off-topic.10/

it has a com connection on the board, that connection is that a control pin? so the voltage can be controlled ? or somthing else, is it is what is required to control it ?

thanks advance !

 

i'm looking to buy a vintage power supply much like this one for sale on eBay

You neglected to post a link or picture of the power supply you're referring to.

it has a com connection on the board

It's likely the ground connection.

 

You neglected to post a link or picture of the power supply you're referring to.
It's likely the ground connection.

damn it! added the wrong link!
https://www.ebay.co.uk/itm/40512257...uid=ZePW_HtaR3G&widget_ver=artemis&media=COPY

 

That is a dual ± output supply.
They appear to share a com (ground) terminal with plus and minus output terminals.
The S terminals are likely for remote sense of load voltage to eliminate the voltage drop of the output wire resistance from the load current.
There are two pots (below) to adjust their respective output voltage.
Not clear what the AC input voltage or output DC voltage is.

 

That is a dual ± output supply.
They appear to share a com (ground) terminal with plus and minus output terminals.
The S terminals are likely for remote sense of load voltage to eliminate the voltage drop of the output wire resistance from the load current.
There are two pots (below) to adjust their respective output voltage.
Not clear what the AC input voltage or output DC voltage is.

View attachment 338711

ahh i see so COM is GND , , yes its not very clear what voltage this one gives when i google the board part number it seems to range what voltages this style of board would produce from 12v to 5v, i suspected at first the com pin it was a communication pin for somthing external,

 

I must be missing something. Is there is anything in that ad specifying the voltage and current capacity? If not, why would you buy it?

 

Nothing on the board is smart enough to have a communications protocol. COM definitely is the common GND for the bipolar outputs. There are no mounting holes, so the original assembly might have used the TO-3 device mounting to secure the board.

ak

 

I must be missing something. Is there is anything in that ad specifying the voltage and current capacity? If not, why would you buy it?

No i don't think so i did mention that when i google the part number of the board, it seems to have a range of 12v or 5v, this board is in alot of different power supplies from what i can tell its from a brand called "power one".

 

Funny, to me, you called this a "Vintage" PS board. It was built the 41st week of 1994. Look at the bottom of the screen capture and you see 4194.

To me, THIS is a "Vintage" power supply:
https://www.ebay.com/itm/235681458941
No PCB (Printed Circuit Board), all point to point wiring. No chips. Not even Tubes. Just a few transformers and capacitors. Can't tell if there are any diodes. I'd imagine there must be if it's a DC supply. The one you call "vintage" is a DC supply. Nevertheless - - - .