Re: Maggie help needed

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Original poster: "michael.tucknott by way of Terry Fritz <twftesla-at-uswest-dot-net>" <michael.tucknott-at-virgin-dot-net>

Hi Antonio
OK OK I think I`m getting the hang of this stuff (NOT).
 Since all three coils are fixed values what happens if I move
the secondary into or out of the primary. I built the driver unit
so the two coils could be moved. If I move the secondary further
out of the primary then the coupling should go down, right ?????
If I`v mist the point I may be able to wind a few more turns on
to the secondary.
I do have another coil that we could use as a resonator, it has a lot
less turns, about 550 on a form 4 1/4" by 13"

> Ok. So, trying the coils in the acmi program, I get:
> L1=79.3 uH
> L2=0.775 mH
> L3=10.7 mH
> k12=0.497
>
> The coupling coefficient is too high for the values of L2 and L3.
> The coupling coefficient should be sqrt(L2/(L2+L3))=0.26,
> or L2 should be higher, 3.5 mH.
> With this L2 you need rather high capacitances at the top of L2.
> Assuming that you can change k12 by rising L2 above L1, or modifying
> L1, the closest modes that I found were (I assumed C3=20 pF. Only the
> ratio C2/C3 is important):
> 7,8,11:   L2=0.772 mH, C2=192 pF, k12=0.259
> 10,11,20: L2=0.784 mH, C2=100 pF, k12=0.261
> 11,12,13: L2=0.740 mH, C2=93.7 pF, k12=0.254
>
> For L1=80 uH, and assuming C3 as really 20 pF, The primary
> capacitance should be only 2.9 nF, to satisfy the relation
> L1*C1=(L2+L3)*C3
>
> A table with values up to mode 15,18,29 is at:
> http://www.coe.ufrj.br/~acmq/magt.txt
>
> Regards,
>
> Antonio Carlos M. de Queiroz