Re: super cheap capacitance/inductance Tesla coil metering

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>

Hi Robert,

At 07:39 AM 12/5/2005, you wrote:
> Think analog...Cheep test equipment can be made. a capacitor across a
> voltmeter as a load will read frequency if you use a constant amplitude
> input. clamp the input with a zener and a input resistor/diode. since the
> input is pulse DC only frequency can charge.  the capacitor over the
> discharge of the meter . If you like parts a LM555 in the one shot mode can
> produce  the DC pulses to charge the capacitor. More pulses per second
> produces more average charge. or frequency indication. This is not for
> digital only analog meters, but I have used it for over 50 years for rough
> quick measurment.

I can make an LMC555, CD4040, 169k resistor, LED, and a cap or two 
for $2 that could probably hit 3% accuracy ;-))  Of course, I am 
thinking of folks that don't even have a meter at all....  At $2, 
that is cheaper than the 9V battery that runs it...  But at that 
point, maybe a TCT tuner is a better deal:

http://hot-streamer.com/TeslaCoils/Misc/TCT/TCT.htm

I bought a cable and a few resistors from Radio Shack for the 
computer thing that costs "more"!!! ($9.00)

Maybe a very stripped down TCT on a little board tuner thing is the 
way to go...  Most of the problem is getting the parts and wiring 
them up.  A very cheap little "kit" would fix that...

> Harbor freight has a capacitance meter available cheeper
> than you can build one.

Do you have any stock numbers????  They change items all the time and 
I know they have had really cheap meters in the past.  I checked 
today and they all seem rather expensive!!!

Cheers,

        Terry


>    Robert   H--
>
>
> > From: "Tesla list" <tesla@xxxxxxxxxx>
> > Date: Tue, 29 Nov 2005 16:58:26 -0700
> > To: tesla@xxxxxxxxxx
> > Subject: super cheap capacitance/inductance Tesla coil metering
> > Resent-From: tesla@xxxxxxxxxx
> > Resent-Date: Tue, 29 Nov 2005 16:52:45 -0700 (MST)
> >
> > 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...
> >
> > Cheers,
> >
> > Terry
> >
> >