Re: 12 volt primary circuit.

• To: tesla-at-pupman-dot-com
• Subject: Re: 12 volt primary circuit.
• From: timp-at-clarityconnect-dot-com (by way of Terry Fritz <twftesla-at-uswest-dot-net>)
• Date: Sun, 19 Dec 1999 17:15:45 -0700
• Approved: twftesla-at-uswest-dot-net
• Delivered-To: fixup-tesla-at-pupman-dot-com-at-fixme

On 18 Dec, Terry Fritz wrote:

> There is a fundamental problem here.  
> 
> A primary circuit has to be inductive.  Usually about 25uH, give or take.  

 So if my primary circuit had a 4.5uF cap with a single turn 1uH coil
 resonating at 75 Khz it would be too capacitive to couple very
 well to the secondary ?

 My origional thoughts were to get the reactance of the primary real
 low and build a secondary with a lot of XL to get the voltage gain
 up there with a battery.

> 
> It also has to operate at a fundamental frequency of say 200kHz, give are
take.
> 
> The "reactance", a resistance equivalent, is R = 2 x pi x F x L == 2 x pi x
> 200000 x 25*10^-6 === 31.4 ohms
> 
> Now to get 100 amps through 31.4 ohms takes 3141.6 volts!!  (V = I x R)
> 
 
> This demonstrates why we need to use high voltages in the primary circuits.
>  We need to have high voltage to force high currents through the primary
> coil's inductance at a given frequency.  So you need to step up the 12
> volts to high voltage for fundamental reasons.  You may be able to get a
> high voltage, 12 to say 20000 volt, inverter circuits to run you coil off
> car or gel-cell batteries but I'll leave those details to others...
> 

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