"Watson A.Name - "Watt Sun, the Dark Remover"" wrote
in message
Suppose that I have an inductor that's covered with epoxy or similar
that prevents me from seeing or finding out how many turns of wire are
on the core. The core is open, so that it's uncovered and most of the
magnetic field is outside outside of the inductor. Obviously it's a
bobbin type core.

Wind turns around it, as you've said. Then drive the unknown core
with some voltage at a high enough frequency that it can actually
develop some voltage (so you can measure it); detect and measure
the voltage at the secondary, (I say detect - depending on what
freq. you use. I don't know the freq. response of a typical DVM),
and the ratio is the ratio. :-)

It shouldn't matter if it's a little lossy, because the turns
ratio is the turns ratio, and the DVM is hi-impedance, right?

Cheers!
Rich