To the forum:

     Currently, I am testing a printed-circuit-board-mount
transformer. There is one primary winding and three
secondary windings. There are two powdered-iron 'E' cores
that are epoxied together around the bobbin to provide the
core for the transformer.

I have a problem where the inductance and the Q of the
primary coil drop way below normal past 1500 Hz with a
signal of 100millivolts AC applied. I suspect that there is
a shorted turn of wire that may be causing this.

Generally, there is maybe 1000+ turns of wire on the
transformer, and the chances of finding a marginal
short-circuit with merely a microscope and the eyes is a
'needle-in-a-haystack' type of chance. Is there some method
that would incorporate an electrical signal that would
enable me to find a short-circuit in the primary winding?

Any and all ideas are welcome. Questions are also welcome.

Regards,

Kelly Schauf

SIGNATURE:
For my webpage containing links to Quality and Electrical
Engineering as well as Failure Analysis (Electronic,
primarily) and ISO9000, go to http://web.gmtcom.com/~k3jsch


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