Re: TC Electrostatics (fwd)

To: tesla-at-pupman-dot-com
Subject: Re: TC Electrostatics (fwd)
From: Richard Hull <hullr-at-whitlock-dot-com>
Date: Thu, 02 Jan 1997 17:22:41 -0800
Subscriber: hullr-at-whitlock-dot-com Thu Jan 2 22:56:37 1997
Tesla List wrote:
> 
> > Subject: Re: TC Electrostatics (fwd)
> 
> Subscriber: bert.hickman-at-aquila-dot-com Mon Dec 23 13:54:40 1996
> Date: Mon, 23 Dec 1996 10:33:28 -0800
> From: Bert Hickman <bert.hickman-at-aquila-dot-com>
> To: tesla-at-pupman-dot-com
> Subject: Re: TC Electrostatics (fwd)
> 
> Tesla List wrote:
> >
> > Subscriber: rwall-at-ix-dot-netcom-dot-com Sun Dec 22 20:25:57 1996
> > Date: Sun, 22 Dec 1996 14:08:41 -0800
> > From: Richard Wayne Wall <rwall-at-ix-dot-netcom-dot-com>
> > To: tesla-at-pupman-dot-com
> > Subject: Re: TC Electrostatics (fwd)
> >
> > 12/22/96
> >
> 
> 
> Richard, Alfred, and all,
> 
> Interesting insights, Alfred. Conservation of energy holds for Tesla
> Coils (and most other things on Chip's list!). :^)
> 
> Richard, trying to change Cs "on the fly", although conceptually
> correct, would be virtually impossible due to the combination of high
> voltages and rapid switching required. Fortunately we don't need to do
> this - there are easier ways! Merely increasing primary capacitance, gap
> breakdown voltage, reducing secondary capacitance, or improving transfer
> efficiency will all increase output voltage, as long as the overall
> system is retuned appropriately. These interrelationships are shown
> below.
> 
> The initial energy available "per bang" in the primary circuit is:
> 
>       Ein = 1/2 (CpVg^2)
> 
> The maximum energy we'll can get out of the secondary will be:
> 
>       Eout = 1/2(CsVs^2) = Ein - Losses (all types)
> 
> Losses include spark gap, resistance and skin effect, secondary ground
> path resistance, premature corona/streamer generation, and radiated
> energy. We'll ignore how efficiency might be measured - we just want to
> see its effect on output voltage. If we let X represent the "transfer
> efficiency" associated with moving energy from the primary to the
> secondary, then:
> 
>       Eout = X*Ein.
> 
> Now, solving for output voltage Vs:
> 
>       Vs = Vg*SQRT(X*Cp/Cs)
> 
> Note that, as Alfred suggests, exactly HOW we transfer this energy does
> not really matter! A Tesla coil simply does it electromagnetically.
> 
> Implications:
> Increasing Cp, Vg, and X, or decreasing Cs will increase Vs. However, Vs
> increases linearly with increasing Vg, but only as the square-root of
> the ratio of Cp/Cs. Large systems tend to significantly increase both Vg
> and Cp, while only moderately increasing Cs (to protect the secondary
> and prevent breakout at higher voltages). Not obvious from the simple
> equations above is that while increasing Cs may reduce output voltage,
> it may increase overall coil performance and sparklength for a variety
> of other reasons! Trying to maximize output voltage is not the whole
> story.
> 
> While there's no such thing as a free lunch, you can get most of what
> you pay for... if you're careful!  :^)
> 
> Safe coilin' to you, and Season's Greetings!
> 
> -- Bert --

Bert,

I think the key issue here was dv/dt and its analog, in this case d 
charge/dt.  The varying capacity of the system's air load in operation 
was the source of ES energy, as posited by Alfred, and the 
electromagnetic part of the Tesla coil is just the tranlational device to 
achieve this end.  I would always conserve the energy and charge.  The 
primary cap increase would obviously increase the capabilities of the 
system from spark to charge output.  The key would seem to be to get the 
capacitve loading of the air to wiggle with greater amplitude.  Lots ta' 
chew on here.


Richard Hull, TCBOR