UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Multi lead power transformer, how to identify windings.

Silicon · 3rd Jul 2012, 12:54 am

I would not connect mains voltage to a winding unless I was sure it was designed to withstand 360v (the peak voltage of the mains waveform).

I would use another transformer with a 6v output (or less) and a current limiting resistor and connect it to the winding that seemed to be the mains primary.

If I guess correctly, the other windings will output a safe low voltage which I can measure and work out the ratios of the windings.

If I guess incorrectly, one of the windings could have a very high voltage on it.

I recently tested some output transformers by feeding 2v ac into the secondary windings.

3rd Jul 2012, 12:54 am	#8
Silicon Nonode Join Date: Jun 2007 Location: Coulsdon, London, UK. Posts: 2,161	Re: Multi lead power transformer, how to identify windings. I would not connect mains voltage to a winding unless I was sure it was designed to withstand 360v (the peak voltage of the mains waveform). I would use another transformer with a 6v output (or less) and a current limiting resistor and connect it to the winding that seemed to be the mains primary. If I guess correctly, the other windings will output a safe low voltage which I can measure and work out the ratios of the windings. If I guess incorrectly, one of the windings could have a very high voltage on it. I recently tested some output transformers by feeding 2v ac into the secondary windings.