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Re: capacitance of homemade caps

Original poster: "Malcolm Watts" <m.j.watts@xxxxxxxxxxxx>

On 7 Apr 2005, at 8:50, Tesla list wrote:

> Original poster: "Steven Steele" <sbsteele@xxxxxxxxxxxxx>
> I've tried using  function generator and an o-scope. the function
> generator doesn't have enough voltage to charge the caps. Don't worry,
> I won't plug it into the wall. ;) I think I'll just wrap the wire
> aroudn the pipe. :) Thanks.

What exactly do you mean by "charge the caps"? If you are expecting
them to be charged up to some DC voltage forget it. A function
generator puts out LV AC. At this point it might be helpful if you
post a picture of the circuit you are trying to implement and some
photos of the equipment you are trying to build. A picture speaks
louder than partial descriptions. Again I think some basic electrical
theory would be rather helpful to you.


> Steven Steele
> ----- Original Message ----- From: "Tesla list" <tesla@xxxxxxxxxx> To:
> <tesla@xxxxxxxxxx> Sent: Thursday, April 07, 2005 12:04 AM Subject:
> Re: capacitance of homemade caps
> >Original poster: Terry Fritz <teslalist@xxxxxxxxxxxxxxxxxxxxxxx>
> >
> >Hi Steve,
> >
> >One "can" measure capacitance and inductance with just a scope. But
> >it is not at all simple. You pulse it and watch to see how fast it
> >discharges across a resistor. I don't think it is worth trying
> >unless you have someone there that knows the technique well... Best
> >to look around for someone that has a meter that just "tells" you
> >such things... Needs a signal generator and some good knowledge of
> >impedances... It is just too messy for a first time scope user...
> >
> >You have mentioned 833Hz which seems way way too low... Maybe like
> >83300Hz... MMCs are real easy since it is just printed on the side
> >of the cap ;-))) Might double check the time and voltage scales on
> >the scope...
> >
> >Don't ground your coil to the AC wall plug!! That ground is great
> >for 60Hz stuff, but terrible at say 83kHz!!! you might fry
> >everything on the circuit. Ground the coil to a little ground rod
> >which is like 1000X better!! cold water pipe or copper drain pipes
> >are great too. Higher frequencies just don't like to travel in the
> >normal household grounding that was never made for such high
> >frequencies.
> >
> >There are some folks that "flush" some bare wire down the toilet to
> >get to the sewer pipes which are very well grounded... Sort of
> >"extreme", but "electrically" sound ;-)) Might not be good at the
> >top floor of a tall building ;-))
> >
> >Cheers,
> >
> > Terry
> >
> >
> >
> >At 06:13 PM 4/6/2005, you wrote:
> >>Thanks. I am indeed already getting some MMCs, I just think it
> >>would be cool to have it running off the strorag boxes. :) Seen on
> >>this website: www.angelfire.com/weird2/customsteele/pics/ Also, I've
> >>got an o-scope with abuilt in signal generator at my school, but I
> >>cant get it to do anything with the box caps. I maintain, perhaps
> >>stupidly, that my caps have a minimum voltage requirement and the
> >>function generator simply can't reach that. I could be wrong, but I
> >>don't think so. :)
> >> Steven Steele
> >
> >