Re: TC Inductance Formulas...

At 05:37 AM 2/21/96 -0800, you wrote:

>Hi Tim,
>Frankly I am a little baffled as to why you need to know the secondary 
>inductance to 8 significant figures.  The exact value is actually rather 
>meaningless because a Tesla coil does not act like a bulk inductor in 
>parallel with a bulk capacitor.  The L and C are distributed and vary with 
>location up and down the coil.  The coil looks more like a coil at the 
>bottom, gradually changing more into a capacitor as it works its way to the 
>top.  The top few turns don't look like turns as much as they look like metal 
>hanging out there.  So you see, the inductance measurement is approximate at 
>best and should only be used for relative comparisons of one coil with 

Thanks for the explaination Mark, and I realize that the inductance of the 
secondary coil is generally used only for comparison.  But I need to find the 
most exact calculated measurment for one purpose and one purpose only.  That 
purpose is because the research I am involved with relies heavely on the 
tesla coil(s) and when the research comes to an end and it comes time to
compile all the results we are surely going to have to do a write up on the 
tesla coil itself, seeing as it is a vital part of the research.  I do not
want to give a calculation or a formula that results in a calculation that is 
almost 2mH off from the measured value.  I also do not want to use 6 different
formulas to calculate the inductance and then take the average of those to
arrive at a inductance which is only 0.01 off, it is not very scientific.

Also the only reason there are 8 significant figures (or more) in my inductance
calculations is because I use a spreedsheet to do keep all the figures and such
organized, it auotmatically does as many significant figures as it can, and I 
did not feel like going through and changes all the ranges.

Besides there is nothing wrong with wanting the most percise calculation...or 
is there...:) 

Hope it unbaffled you,


| Timothy A. Chandler                ||   M.S.Physics/B.S.Chemistry     |
| NASA-Langley Research Center       ||   George Mason University       |
| Department of Energy               ||   Department of Physics         |
| FRT/Alpha - NASALaRC/DOE JRD/OPM   ||   Department of Chemistry       |
| CHOCT FR Designation #82749156/MG09||   OPC-EFC                       |
|                 Private Email Address:  tchand-at-slip-dot-net               |