Re: Tesla Coil Blunders

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

Original poster: "Ed Phillips by way of Terry Fritz <twftesla-at-uswest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
> 
> Original poster: "by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<Parpp807-at-aol-dot-com>
> 
> In a message dated 3/28/01 6:14:21 PM Central Standard Time, tesla-at-pupman-dot-com
> writes:
> 
> <<  At the risk of sounding pedantic I don't think you can have "DC
>  inductance". I think
>  inductance is usually measured at something like one Khz. 

	That is a convenient frequency for bridge excitation and is often used
for reference.  There are methods for measuring the "DC" inductance, but
they are more suited to a standards lab than to the usual workbench.

> It is on my
>  bridge anyway. Please feel
>  free to flame away if I have got this wrong.

	Well, the inductance of a solenoid does change slightly with frequency,
due to the modified current distribution in the wire due to the skin
effect.  The effect is small and almost certainly of no importance in TC
secondary calculations, where an accuracy of a few percent really
doesn't matter, as the tuning of the coils must be adjusted eventually.

Ed