Transformer repair / fix

Repair a small AC transformer  by removing the heat / overload fuse inside the transformer.


Here is a trick to possibly revive / repair a transformer that is not working anymore. Most transformers nowadays come with a built in heat and overload protection fuse. Some fuse's are resettable while others are not  (these ones just fuse out).

If you overload your small transformer 1 or 2 things could happen. 1) If you are lucky the transformer has a built in fuse that will 'blow' , thereby protecting the transformer. 2) The transformer  will over heat and will be un repairable .

Please note that by doing this you are creating a potential fire hazard as the transformer could overheat - do so at your own risk.

I have done this mod many times and have not encountered any problems.

So to remove the 'fuse' we first have to open the transformer. Do this by cutting away at the insulating coverage VERY carefully so as not to damage the wiring inside.

Transformer repair / fix

 Once removed we can see the wiring.

Transformer repair / fix

 Next locate the 'fuse and remove it. In this example the 'fuse' was on the other side of the transformer.

Transformer repair / fix

Here is the 'fuse' removed and the transformer wires connected to the AC input.

Transformer repair / fix

Next I added a bridge rectifier as this was a AC - AC transformer. Bridge rectification transforms the AC voltage to DC voltage.

Transformer repair / fix

 Testing and making sure all is working

Transformer repair / fix

 Put together with some air holes to allow the heat to escape and the transformer to operate slightly cooler.

Transformer repair / fix

Now I can power my modded desk lamp with a 10 Watt 12 volt LED installed.

Transformer repair / fix