[Shop-talk] Mystery of the blown transformers

[Rich White]

Jim,

I think your problem is that the replacement transformer is not up to the
job.
As others has said you could calculate the cold resistance, but maybe it would
be better to measure the current before dies.

When picking out a replacement, you have to look at the continuous load
rating.  A door bell would be a very short duration load and I would not
expect the transformer to handle its rated output continuously.Rich White St.
Joseph, IL USA
'63 TR3B TCF587L
That ain't a scrap pile, that is my car!
See it moves!