Power Supply parts?

[Runninfarmer]

I recently bought a power supply off ebay, and with no surprise, isn't working right. Is there any sites that sell replacement parts for power supplies like transformers, etc. Im thinkin it might need a new transformer, but not sure though. Thanks for any help

[Spyman]

The transformer is usually the most robust part in a power supply.

(If it's toasted, a lot of other parts is too...)

 

Why do you think the transformer is broken ?

 

There is a lot of places that sell transformers or other electronic parts. But transformers come in the range from the small size of a sugar cube to the large size of buildings. Without details of the power supply unit it's hard to help.

[YT2095]

yeah, throw us a bone at least!

[Runninfarmer]

I did some tests on it and I think the transformer is all right, but maybe somebody knows what could be wrong with it. It's a Sorensen QRD 60-1.5 and the power light comes on, but no power comes out of the terminals. I don't see any visible burn marks on any components on it. The circuit looks pretty complicated though.

[DrDNA]

Ah ha.

We're professionals. We don't mess around.

Have you tried spitting in it and giving it a good wack?

 

There are manuals for it on ebay. $10 and $30

 

http://cgi.ebay.com/SORENSEN-QRD-POWER-SUPPLIES_W0QQitemZ160162505799QQihZ006QQcategoryZ25409QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

 

http://cgi.ebay.com/Sorensen-QRD-Series-OP-SVC-Manual_W0QQitemZ7619069376QQihZ001QQcategoryZ25409QQrdZ1QQssPageNameZWD1VQQcmdZViewItem

[NeonBlack]

I agree with trying to "give it a good wack"

The effectiveness of percussive reparation is astounding.

Stick a screwdriver or something in it and wiggle it around a little.

[DrDNA]

I agree with trying to "give it a good wack"

The effectiveness of percussive reparation is astounding.

Stick a screwdriver or something in it and wiggle it around a little.

 

If violence and the screwdriver don't do it, perhaps the gentle approach is worth a shot.

....complements, flowers, romantic dinner, good wine, a few candles, soft music, clean sheets, lingeri.....

[Spyman]

It's a Sorensen QRD 60-1.5.

Google search turns up:

Sorensen QRD 60-1.5 Power Supply 0-60V / 0-1.5A

OK, so it's an adjustable Voltage 0-60 V DC and adjustable Current 0-1.5 Amps power supply.

 

 

I did some tests on it and the power light comes on, but no power comes out of the terminals.

Well, then I think it's safe to rule out the transformer and main fuses.

 

What about the Voltage meter, does it correspond when turning the knob for Voltage ?

(The meter switch needs to be in "V" position.)

 

Also in some power supply the Current knob when turned to zero can cut off the output Voltage.

 

And, yes, what does the Ampere meter show, when the switch is in "A" position ?

 

 

I don't see any visible burn marks on any components on it. The circuit looks pretty complicated though.

I interpret that as you have already opened the housing.

 

How are your electronic skills and do you have a test Voltmeter or similar instruments ?

 

 

maybe somebody knows what could be wrong with it.

Some suggestions:

 

The PS looks cind of old style, at least in the picture I have found with Google, and the output current is quite small, so it's possible that the output goes through the meter and/or the meter switch, which then could interupt the power if they are broken.

 

It's also possible that there is an output fuse, if so, it's likely placed on the circuit board close to where the wires to the output terminal is connected, or somewhere along those wires between the board and terminals.

 

Potentiometers, (behind the knobs), can oxidate if not used for a long time, usually it's enough to turn them all the way up and down a few times to establish contact. Have also happended to me, more than a few times, that reckless pre-owners have used extensive force while turning the knobs beyond the end, which causes the potentiometer housing to turn and eventually rips off the three wires connected to it.

 

 

And take care if/when the mains is connected, electric chock can be lethal !

[Runninfarmer]

My electronic skills are decent but not great, but two Physics professors and I tested moving the knobs and nothing happens. I guess I remember we found that a constant few tenths of a volt came out of the terminals, but didn't change when we messed with the knobs. There's a fuse in the back that I just replaced. The analog meter on the power supply doesn't work for the voltage or amperage. Thanks for the info.

[Spyman]

...a constant few tenths of a volt came out of the terminals...

I can add with that info that it also could be some internal short before the current meter.

(A few tenths of volts is enough to drive 1.5 Amperes through a short.)