1) you guys are just arguing symantics. You both know what really happens.
".... "Inductance" vs. the total reactance measuring as inductive...." call
it what you like.

1a)
You are also both using (some might say mis-using) the term "linear" to mean
"varies linearly with..." rather than the more common meaning that
superposition applies. RLC sircuits are linear. Any given parameter may
not vary linearly as the frequency is varied. Also, this use of 'linear'
depends upon the type of scale being used--log or linear.

2) John,
You better re-think your last statement about the series equivalent of a
practical coil. It implies that there is some way to measure a low Z at the
resonance of the coil under discussion. You say:
"The series
equivalent [impedance ? Steve] goes down as the frequency increases,
and goes to zero at
resonance. "
While a series resonant LC exhibits this behavior, the series equivalent
of a practical coil does not do this. The series equivalent must do the
same thing as the parallel equivalent -- namely go to a high impedance at
resonance. That's why it is called *equivalent*--the total, or terminal
impedance is equal for the two representations (at a single frequency).

Pretty sure I got that right....
Steve
k]9]d]c]i


A practical coil usually goes to parallel resonance - at which the series
equivalent does not go to zero
"John Woodgate" wrote in message
...
I read in sci.electronics.design that Bill Turner
wrote (in ) about 'Winding
coils', on Sun, 7 Dec 2003:

Both statements are true and easily provable. A simple air core coil
which measures one microhenry at a low frequency may have an inductance
of several millihenries (or even henries) when near its self resonant
frequency.

This is what happens to the *parallel equivalent* inductance. The series
equivalent goes down as the frequency increases, and goes to zero at
resonance.
--
Regards, John Woodgate, OOO - Own Opinions Only.
http://www.jmwa.demon.co.uk
Interested in professional sound reinforcement and distribution? Then go
to
http://www.isce.org.uk
PLEASE do NOT copy news posts to me by E-MAIL!