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Re: distributed capacitance measurement?
From: DR.RESONANCE[SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent: Thursday, September 04, 1997 11:32 AM
To: Tesla List
Subject: Re: distributed capacitance measurement?
To: Jim M
It's easy. Measure the inductance of the sec coil. Next measure the
resonant freq of the sec coil without a toroid on it. You now have two
values Lsec and Fres. Now just use the classic freq formula and a little
algebra -- solve for C. Plug in your measured numbers and the resultant
value C is the distributed capacitance of the sec inductor.
DR.RESONANCE-at-next-wave-dot-net
----------
> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-poodle.pupman-dot-com>
> Subject: distributed capacitance measurement?
> Date: Thursday,September 04,1997 8:43 AM
>
>
> From: bmack[SMTP:bmack-at-frontiernet-dot-net]
> Sent: Wednesday, September 03, 1997 10:09 PM
> To: tesla list
> Subject: distributed capacitance measurement?
>
> To All,
>
> How the heck do you MEASURE the distributed capacitance
> of a secondary?
>
> I have a several methods to determine f-res and Q, but don't
> have a clue how you can separate the system into L and C for
> true empirical measurement.
> Unless you are calculating it from the approximate known value
> of L when resonance is determined? Thats what I use,-but that's
> NOT a measurement.
>
> Another indirect method might be to use lisajous figures on a
> scope to determine the 45 degree point in a LR circuit (the R
> being a variable) at a low and high freqency ( below Fr). the
> reactance difference would represent it's distributed capacitance,
> at the higher freq used. For best results, get close to Fr.
> As you know, all electronic component values are frequency
> dependent-even resistors! The problem gets worse as one progesses
> upward into hf -the uper limit for Tesla coils.
>
> The last paragraph is pure speculation on my part. Has anyone tried this?
>
> Thanks in advance
> Jim M
>
>
>