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Re: Help with calculating secondary self resonant freq?



Original poster: "Ed Phillips by way of Terry Fritz <teslalist-at-qwest-dot-net>" <evp-at-pacbell-dot-net>

Tesla list wrote:
 >
 > Original poster: "Antonio Carlos M. de Queiroz by way of Terry Fritz 
<teslalist-at-qwest-dot-net>" <acmq-at-compuland-dot-com.br>
 >
 > Tesla list wrote:
 >  >
 >  > Original poster: "Ed Phillips by way of Terry Fritz
 > <teslalist-at-qwest-dot-net>" <evp-at-pacbell-dot-net>
 >
 >  >  > coil, the coil winding is 11.625 inches high 1662.375 turns of 34 
gauge
 >  >  > enamel wire and the diameter of the coil 2 3/8 wide on standard PVC,
 >
 >  > fr = 426.4 kHz
 >  > cd = 4.54 uufd
 >  > L = 30686 uh
 >
 >  >         Be interesting to see what others get.
 >
 > "translating":
 > 11.625" = 29.53 cm
 > 2 3/8" =  6.0325 cm, radius=3.016 cm
 > #34 wire has diameter=0.16 mm, so a better radius is 3.024 cm
 > Plugging these numbers in the Inca program, with 1662 turns, the
 > several calculation methods implemented give:
 > Wheeler    30.9196154870 mH
 > Lundin     31.0100380336 mH
 > Lorenz     31.0100900787 mH
 > Snow       30.9603149701 mH
 > Kirchhoff  30.9602456812 mH
 > Maxwell    30.9735485605 mH
 > They all agree reasonably at ~31 mH.
 > Combining 31 mH with Medhurst's self-capacitance, 4.55 pF: 423.77 kHz.
 >
 > Antonio Carlos M. de Queiroz

	"Close enough for government work."  Of course, any added capacitance
due to leads, scope probes, etc. will lower the frequency, so this value
is mainly of theoretical interest
.

Ed