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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