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Old UPS transformers: Any uses? Answered

Does anyone know of a use for those massive transformers found in dead UPS's?

Please don't post replies that include "door stop" or "recycle them" because those are obvious replies when you have no answer to my question. *SMILE*

I have not tried but if the "secondary" for those that is the 110v output to the plugs were hooked to 110, do the original primaries become low voltage ac secondaries? (~12v)

I have accumulated about 6 of these and would like to find an electronic use for them before resorting to recycle. 

I have no doors that need propped open. Thanks.


Well if the UPS transformers output is connected to service you should be able to use the 12 volt side as a spot welder.

inverter for use in the car. Is the DC side 12v

Oh, I have 2 genuis ideas:

1. Use them as a door stop

2. Recycle them!

I have two of them, and I'd like to turn them into 12V power supplies. Since they charge 12V L-A Batteries, I suppose that it shouldn't be a problem.

It's been on my To-Do list for months...

(And if you do that, it would be AWESOME if you posted an Instructable)


What are the relative numbers of turns on them? (Or the in/out voltages?)

They may be suitable for building a welder or generating high voltages for things like a Jacob's Ladder.

You need to first check how they work or at least measure the transformer outputs properly.
I had them in all sorts of configurations, which isn't making things easier.
Some do have a secondary winding offering mains power as a means of seperating and faster switching to the battery.
Others have a direct output for charge and the inverter part and always feed the connected devices through the inverter.
Last but not least you have the cheap china crap that only has a 14V output on the transformer and nothing else.

Without knowing what types you have the only answer I can give would be:
Check the output voltage and how much power they can supply and find a suitable project for it.
If the remaining electronics are still good you can use them to create an inverter for camping use.