RE: Gary's inductance measurement Was: Inexpensive LCR-Multimeter

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Lau, Gary by way of Terry Fritz <teslalist-at-qwest-dot-net>" <Gary.Lau-at-hp-dot-com>

Hi Bart:

The study I did was focused on the AC resistance of primary conductors, so 
I never tried a secondary coil.  The results are at 
http://www.laushaus-dot-com/tesla/primary_resistance.htm.

To be complete, I should add that I did observe a small degree of 
inductance frequency-dependence on primary coils that had a significant 
portion of unused turns, but this was only evident at frequencies above 400 
KHz.

Gary Lau
MA, USA

  -----Original Message-----
From: 	Tesla list [mailto:tesla-at-pupman-dot-com]
Sent:	Thursday, January 09, 2003 9:42 AM
To:	tesla-at-pupman-dot-com
Subject:	Gary's inductance measurement    Was: Inexpensive  LCR-Multimeter

Original poster: "Barton B. Anderson by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <tesla123-at-pacbell-dot-net>

Hi Gary,

While browsing through today's postings, I see you measured primary
inductance characteristics and noted negligible change with frequency. I
expect you have made this measurement with the secondary also. If so, can
you confirm inductance change with frequency in the secondary and
approximately how much? If you've already posted that data, please forgive.

Take care,
Bart

Tesla list wrote:

 >Original poster: "Lau, Gary by way of Terry Fritz <teslalist-at-qwest-dot-net>"
 ><Gary.Lau-at-hp-dot-com>
 >
 >Why is it necessary to measure inductance at different frequencies?
 >My characterizations of different primary coils with a _very_ expensive
 >HP4194 impedance/gain-phase analyzer showed negligible variation of
 >inductance with frequency.