"Reg Edwards" wrote in message
...
If it is an air-cored inductor, calculate the number of turns from its
measured dimensions.

This won't work with a ferrite core because its material permeability
is not
known. Although if the core is a simple rod the effective permeability
is
roughly 25 regardless of material permeability.

With a high permeability core, 100 or more, effective permeability
becomes a
function only of the very long 'air gap'. So inductance stops
increasing
with increasing core material permeabilty.

Thanks for the interesting info. I would expect the core to be more of
a bobbin. But when it's covered, it's not always certain.

But why would you want to know the number of turns if the coil is
already
wound!

If I don't know the number of turns to begin with, do you expect me to
UNwind the coil to find the number of turns?

As I said, the coil is usually covered or potted in epoxy.

----
Reg.