Need help about the following transformer....

Thread Starter


Joined Oct 1, 2013
Hello everyone i am new to all about circuits, this is my first post too....
I have attached an image of the transformer from an old ups(intex 600va).
i am trying to use this one for my bench power supply which i am going to make.
I need those configs of the transformer.thank you in advance,.......



Joined Oct 10, 2010
First you have to identify the input and the output. I assume that the input is at where red and blue wires are because they are bigger.

If this is correct, you have four wires at the output side. Most probable you have a transformer with middle connection at that output. For example, +12V / 0 / -12V.

Upon your needs, you may have two outputs +12V and -12V our you may have only one output with 24V or only one of 12V depending on the combination you do with your output wiring.

Usually you'll have each output within two consecutive wires. In this case,
*output 1 = black and green;
*output 2 = blue and yellow;

Now this is just a first assumption. You should look at the outputs with a two-channel oscilloscope before doing any connection.

If you give us the oscilloscope figures, we could go further in the implementation.


Joined Jul 13, 2008
Gotta say that transformer looks awfully small to be out of a UPS unit, but then it probably isn't the main T-1

Easiest way to roughly evaluate your unit, is to hitch a low known-voltage AC from another transformer or a wall-wart, preferably 10 volts [ makes math easier ] into your primary, which appears to be the Red / Blue per your picture... The low voltage, reduces the " Oops Factor " if the hookup regimen below is wrong. You won't hurt the unit

Then measure the output voltage produced by all combinations of the other four leads > I would think it is a one coil, with black as common, providing 3 levels of voltage...

Make your test hookups, with your primary feed through a momentary switch, it will allow brief connections to your meter on the secondary side, and should not kill either the trans, or your meter...

A couple things escape me here... UPS unit transformers usually have a heavy coil for a battery back-feed to an inverter arrangement... You didn't specify what your working input voltage is over yonder, tho' I imagine you're running ~240 volts @ 50 Hz...
Last edited: