Putting an Unknown Transformer to good use

Thread Starter


Joined Mar 13, 2011
<Moderator's note: Your question is important enough to have its own thread so it gets more attention. Now you have your own thread.>

I came across this thread when looking to find the VA rating on a transformer I have (it may have come out of an old model railway controller). There is single primary input and dual secondary outputs. At 230VAC input, the secondaries give 12.5VAC under no load The only marks visible are...1192-0087 NTC 9637...it weighs 960g and the windings measure 50 x 50 x 40 mm excluding the 'plates'. I thought it would be easy to search for and find the VA rating for this transformer, I assumed that NTC was the manufactures name or logo but I can up with nothing. Can someone come up with any info on this or point me in the right direction.

Many thanks


Joined May 19, 2014
Don, you already have your answer and it is a good one. I would like to share some additional information that surprised me.

I, like Max, looked at some transformers I have in hand. Here is some data.

Core volume verses VA (outside dimensions)
LP-30-1600 48VA 65,000 cubic mm
F28-700 20VA 50,000 cubic mm
The LP has 30% more core volume but is VA rated 240% higher than the F28.

Dons Transformer has a core volume of about 112,000 cubic mm.