Re: Coupling - ACMI trend

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

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

Hi Bart,

        Great to know the new secondary diameter helped!!  I ordered "10 inch"
Sonotube but I guess they have all kinds of 1/4 inch increments so they can
ship them one inside the other.  I think it was a year before I happened to
notice it was really 10.25 inches.

I used the "Best method" with AC line current in the primary and a meter
reading the voltage on the secondary.  I guess I missed this sort open resonant
frequency method but that takes equipment most people don't have.  Also, Fo can
be affected by many things so I would worry a bit about it being super
accurate.  However, it does look like a really neat thing to experiment with!

The measurements I took should be very accurate because I really tried hard
;-))  However, it is surprising that I was only 0.001 off!  Of course, I assume
the program is right and "I" am in error ;-)))

I have not played much with this ACMI thing yet but I had better get to it!!

Cheers,

        Terry


At 04:08 AM 12/22/2000 -0600, you wrote: 
>
> Hi Terry, Paul, All, (this is amazing to me) 
>
> Terry, in an attempt to more accurately model your primary and secondary
> values, I took your new secondary diameter and misc. other details refining
> data inputs to achieve as near a model as your coil should be via dimensions
> and measurement. (I tried the first time, but did better with this bits of
> info). Values required for acmi is then thrown into Excel to do a quick
> convert to meters and input into a file, Terry.in. I ran each height (also
> entered in meters) for each measurement. 
>
> Oh my, how things changed: 
>
> (inch)  terry    acmi 
> Height    K        K     delta    err% 
>   0    0.207    0.206    0.001    0.49 
>   1    0.175    0.176    0.001    0.57 
>   2    0.148    0.148    0.000    0.00 
>   3    0.124    0.125    0.001    0.81 
>   4    0.105    0.106    0.001    0.95 
>   5    0.089    0.090    0.001    1.12 
>   6    0.076    0.077    0.001    1.32 
>   7    0.065    0.066    0.001    1.55 
>   8    0.056    0.057    0.001    1.79 
>   9    0.049    0.050    0.001    2.04 
>  10    0.042    0.043    0.001    2.38 
>  11    0.037    0.038    0.001    2.70 
>  12    0.032    0.034    0.002    6.25 
>  13    0.029    0.030    0.001    3.45 
>  14    0.026    0.026    0.000    0.00 
>  15    0.023    0.024    0.001    4.35 
>
> How's that for accuracy of a program? Paul, I think you should wait a while
> until more data can be checked and rechecked before making any changes to
> acmi. IMHO, it did an outstanding job here. Every time acmi has better
> inforation for inputs, the program gets real close to measured values (real
> close here - again, Terry's excellent measurement techniques show through). 
>
> Terry, did you use amp/volt readings concentrically and/or did you use
> frequency analysis to measure K? 
>
> Take care, 
> Bart 
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