Re: More Coupling...

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

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

Hi Paul, 

Tomorrow I'll take measurements for any background levels. The next K
measurements I do will be concentric amp/volt readings. 

I've been working with acmi much fo the day. Looking at comparisons of coils
with two measured inductances, acmi represents very well. I am doubting the LCR
meter reading on my coil I took back in MN. I need to measure again to be sure.
However, I've come to a conclusion that there must be dimensional errors. I
brought the coil in middle of the living room (wifes at work) and went through
it. Found the length at 44" but I have 2 areas that are missing windings (1/4"
gap each). One is from a burned turn a couple years ago and the other is where
I added 12" of winding to what was then a short secondary. I'm refining every
possible measurement, including primary. I used a calc'd Ls in acmi today
working with this. 

Things are better (error has decreased but still trends same direction). 

I threw together the latest data to place on the web. I'll post back when I put
it up. It will be a place to simply display/store/reference my use of acmi
against measured coils. 

I have found this "most important" when working with acmi: 
"Coils measured inductances must be input correctly into acmi via dimensions
for accuracy". Since acmi uses dimensions, any coilers rough or even relatively
precise measurements are not enough. There is human error in building and
oversites. These flow into the program if not modeled first in a TC program.
Entering coil data into a TC modeling program (JavaTC, JHCTES, Ed Sonderman's
spreadsheet, etc..) allows the user to make slight adjustments to duplicate
measured inductances. When this is peformed, these "fine tuned" dimensions can
then be entered into acmi. Acmi then calcs almost identical Ls and Lp values
and also becomes "sweetly" accurate. 

Great job with the gradiant graphs. They open up some interesting topics of
discussion and future tests. 

Take care, 
Bart 

Tesla list wrote: 
>
> Bart, another quick check you can make - measure your secondary 
> voltage with the primary circuit connected through the dryer, etc, 
> but with the dryer switched off, ie no primary current. Let's see if 
> a background 60hz pickup exists which is enough to affect the  k 
> values. Depending on the phase of the stray induced voltage wrt the 
> desired induction from the primary, the background may add or subtract 
> from the reading. Alternatively, reverse the primary connections and 
> repeat the +2" and -2" readings. 
>