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Re: 60 vs. 30 ma


From: 	Micheal Huff[SMTP:msnock-at-theonramp-dot-net]
Sent: 	Monday, June 23, 1997 9:26 PM
To: 	Tesla List
Subject: 	Re: 60 vs. 30 ma

Tesla List wrote:
> 
> From:   Shawn Collins[SMTP:rubidium-at-worldnet.att-dot-net]
> Sent:   Monday, June 23, 1997 1:47 PM
> To:     Tesla List
> Subject:        Re: 60 vs. 30 ma
> 
> At 01:24 PM 6/22/97 +0000, you wrote:
> >
> >From:  Alfred A. Skrocki[SMTP:alfred.skrocki-at-cybernetworking-dot-com]
> >Sent:  Wednesday, June 18, 1997 7:29 PM
> >To:    Tesla List
> >Subject:       Re: 60 vs. 30 ma
> >
> >Wednesday, June 18, 1997 8:10 AM Gary Lau
> ><lau-at-hdecad.ENET.dec-dot-com> wrote;
> >
> >> >Actually you do have to increase the capacitor size if you increase
> >> >the charging current otherwise you will not be using the additional
> >> >current. Realize of course this assumes that you were already using
> >> >the largest practical size capacitor for the charging current. The
> >> >capacitor is really the controlling factor as to how much power we
> >> >can cram into a given Tesla coil.

The above is true.  Capacitors have a form of resistance (called
"reactance", it's not like normal resistance, but the same base unit,
the ohm is used.) when used in AC circuits.  This can be determined by
the simple formula for capacitive reactance:

Xc (reactance) =      1
                  ---------
                2 * pi * f * C
pi = ~3.1415
f is frequency (commonly 60hz)
C is capacitance of capacitor(s)

Since ohm's law does apply to reactive devices you can easily find the
most efficient sized capacitor for the tank circuit.  Just figure out
the transformer's impedance.  Maximum power transfer always results when
the source's impedance equals that of the load.


NeonZ = 12000 / .030  

MaxCapSize =      1
             -----------
         2 * 3.1415 * 60 * NeonZ

MaxCapSize is in Farads

As with resistance, you can have all the current available in the world
available to charge that 6.6nF cap (matched to a 12kV -at- 30mA neon) but
to force 60mA across it you're going to need 24kV -at- 60mA.

Mike
-- 

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