Re: super cheap capacitance/inductance Tesla coil metering

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: "Jon Danniken" <danniken@xxxxxxxxxxx>

> Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi All,
>
> Making an oscillator with a 555 timer to measure capacitance is on my
> mind.  I "think" it could do inductance easily too...
>
> I was thinking of a trivial LM555C timer circuit powered by a 9V
> battery that would plug into the sound card jack of a computer to
> read the frequency.  A little program might be able to do the math
directly...
>
> Thus, one might be able to make a LC meter for like $5 which I think
> many of us would like.
>
> There is probably some free program out there that does the "sound
> card input jack to frequency readout" function????
>
> Everyone has a sound card these days and plenty of resistors protect
> the computer...  So the "high level" hardware is already done...
>
> I suppose such a thing could be made into a Tesla coil primary and
> secondary "tuner too"...  A PC with a sound card plus some cheap and
> easy "Radio Shack" parts is a pretty powerful machine!!! It really
> could be a sound out cable to alligator clips and a resistor
> protected similar input cable if you had nice software...
>
> I know the hardware side, but not the software side...
>
> Hmmmm....
>
> It would be a cool addition to Tesla coil design programs...  I would
> love to be able to send out $10 worth of stuff for someone to hook to
> their coil and it would read back everything we need to know about it
;-)))
>
> Just a thought...

That sounds like a fantastic idea, Terry.  If you can "squeeze" the
frequencies into the ~20kHz bandwidth of an average soundcard, this would be
a tremendously useful device for those of use without regular scopes.

On the software side, the main freeware PC Oscilloscope I have found is the
one at MSU on this page:
http://polly.phys.msu.su/~zeld/oscill.html

Jon