Re: Coupling - ACMI trend

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

Original poster: "Terry Fritz" <twftesla-at-uswest-dot-net>

Hi Bart and Paul,

I would like to point out two things.

First there is an error I just saw in the paper.  The secondary is 10.25 inches
in diameter and not 10 inches in diameter.  That will make a difference in this
case.

Second, I don't thing the "err%" column is valid.  With the measurements
loosing so much precision as they get smaller.  A tiny measurement error could
make a big difference in the err% number.  I would think a simple delta would
be better:

>
> inch   acmi    Terry     delta 
>  0    0.199    0.207     -0.006 
>  1    0.171    0.175     -0.004 
>  2    0.147    0.148     -0.001 
>  3    0.126    0.124     0.002 
>  4    0.108    0.105     0.003 
>  5    0.093    0.089     0.004 
>  6    0.080    0.076     0.004 
>  7    0.070    0.065     0.005
>  8    0.061    0.056     0.005 
>  9    0.053    0.049     0.004 
> 10    0.047    0.042     0.005 
> 11    0.041    0.037     0.004 
> 12    0.036    0.032     0.004
> 13    0.032    0.029     0.003 
> 14    0.029    0.026     0.003 
> 15    0.026    0.023     0.003 


 From this, the error looks constant and measuring coupling to the thousandths
is sort of wishful thinking ;-))  Perhaps the diameter correction will bring
these numbers in closer.

Also to clarify the primary dimensions:

The primary starts at 12.0 inches diameter.  I has a 3/8 inch (0.375) pitch and
has 19.6 turns total of which 15.125 are used so the outside diameter is 23.34
inches.  Of course, spirals really don't have a "diameter".  So the beginning
has a radius of 6.0 inches and the 15.125th turn point has a radius of 11.67. 
I take all those from the center of the spiral to the center of the 1/4 inch
tubing.

Cheers,

        Terry


At 12:43 AM 12/22/2000 -0600, you wrote: 
>
> Hi Paul, Terry, All - 
>
> Tonight I ran Terry's coupling numbers (obtained from website) against acmi. 
>
> Terry's coupling measurements were from 0" to +15" (sec. above pri.): 
>
> (Terry's numbers are rounded to 3 out) 
> inch   acmi    Terry     err% 
>  0    0.199    0.207     3.97 
>  1    0.171    0.175     2.51 
>  2    0.147    0.148     0.34 
>  3    0.126    0.124     1.45 
>  4    0.108    0.105     3.25 
>  5    0.093    0.089     4.73 
>  6    0.080    0.076     5.26 
>  7    0.070    0.065     8.19 
>  8    0.061    0.056     9.52 
>  9    0.053    0.049     8.38 
> 10    0.047    0.042    11.64 
> 11    0.041    0.037    11.11 
> 12    0.036    0.032    11.11 
> 13    0.032    0.029    11.89 
> 14    0.029    0.026    13.28 
> 15    0.026    0.023    15.04 
>
> Minimum err% appears at +2" but increase either direction from this point.
> Too bad we don't have measurements below 0". Obviously, 15" is extreme, but
> from 0" to +2" above primary, the err% is low which is the typical range
> coilers will run and again shows the program can be very useful. Also, this
> is a nice flat primary (big 10" coil) and has less err% than I saw in my
> range. 
>
> Terry's coil specs are at: 
> 
> <http://hot-streamer-dot-com/TeslaCoils/MyPapers/sgap/sgap.html>http://hot-str
> eamer-dot-com/TeslaCoils/MyPapers/sgap/sgap.html 
>
> Paul, you may want to run some of these numbers yourself - I'm still getting
> use to meters (grin). Terry's pri - sec spacing appears to be about 1". My
> spacing is nearer to 2", so I can see why his coupling at 0 for example is
> 0.207 higher than on my coil at 0.165. I may run acmi to check a what if? I
> like this program! 
>
> Take care, 
> Bart 
>   
>