# Re: Magnifier coils

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From: 	DR.RESONANCE[SMTP:DR.RESONANCE-at-next-wave-dot-net]
Sent: 	Thursday, July 17, 1997 8:27 PM
To: 	Tesla List
Subject: 	Re: Magnifier coils

TO: Bert Wikkerink

A classic Tesla circuit consists of a primary coil with a secondary coil
inside and usually slightly above the primary.  Energy is coupled into the
sec. coil where it resonates and most of the energy produces the desired
high voltage spark if the tuning is matched properly and the coeff. of
coupling is around 0.18 to 0.22.  As the system becomes larger and larger
the inter-turn capacitance of the sec. coil and other factors (like poor or
too slow spark gap quenching) cause a reflection of power back into the
primary circuit where it is not desireable.  Tesla wrestled many years with
these problems and finally concluded the best way to solve the problem is
to get rid of the coupled pri - sec coil system and achieve resonant rise
in a high frequency circuit due to its Q or quality factor.  A high
potential oscillating current applied across an inductor will rise in
potential if the Q factor (related to large inductance, low resistance, and
proper resonant freq) of the inductor is large.  The actual equation is V
(out) = Q x V (in).  Tesla decided to apply the output of a classic
oscillator with pri & sec coils to another distant coil that is not coupled
magnetically to the primary coil.  In short, he fed the output of one
classic system directly into another elevated secondary coil sitting
several feet away.  There is a resonant rise in the third coil and
sometimes quite dramatic if the circuit factors are right.  This third coil
is referred to as the "magnifier" coil while the first pri-sec coil of the
system is called the "driver".  The driver requires very tight coeff. of
coupling (usually 0.5-0.7) and supplies a very powerful base current to the
magnifier coil which then multiplies the output potential to very high
levels.

Rich Hull and his TCBOR group have done a lot of outstanding work in this
area and perhaps they will comment further on this phenomonea.

DR.RESONANCE-at-next-wave-dot-net

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> From: Tesla List <tesla-at-pupman-dot-com>
> To: 'Tesla List' <tesla-at-poodle.pupman-dot-com>
> Subject: Magnifier coils
> Date: Thursday,July 17,1997 12:09 AM
>
>
> From: 	Bert Wikkerink[SMTP:bert-at-mitra-dot-com]
> Sent: 	Wednesday, July 16, 1997 10:18 AM
> To: 	Tesla List
> Subject: 	Magnifier coils
>
> Hi all,
>
> I've heard the term magnifier coil used a number of times and I was
> wondering what exactly they are ?. How are they different from a tesla
> coil ?.
>
> Thanks
>
>

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