Re: Magnifier coils

From: 	FutureT-at-aol-dot-com[SMTP:FutureT-at-aol-dot-com]
Sent: 	Thursday, July 17, 1997 4:14 AM
To: 	tesla-at-pupman-dot-com
Subject: 	Re: Magnifier coils

In a message dated 97-07-17 00:55:33 EDT, you write:

<< 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


A magnifier has three coils; primary, secondary, and an extra coil or 
resonator.  The primary and secondary are closely coupled at about
k = .4 and the secondary has fewer turns of thicker wire than an 
ordinary Tesla coil.  A wire or metal rod is connected from the top of
the secondary to the bottom of the extra coil which is placed a number
of feet away from the primary/secondary.  There is no magnetic
coupling between the primary/secondary and the extra coil.  Voltage
rise occurs in the extra coil by the resonant rise effect of a tuned 
resonant coil.

Because of the tight coupling in a magnifier, the spark is required to
quench faster than in a normal Tesla coil, this demands special 
attention to the spark gap system.  Nikola Tesla used the magnifier
design at Colorado Springs and at Wardencliffe.

I've built a small (5kW) magnifier, and some of the list members such 
as Richard Hull, Ed Wingate, and Bert Pool, have built larger magnifiers.

At the power levels I used, I didn't see any efficiency advantage over a
normal Tesla coil.

Another magnifier experimenter is Lou Balint of PA.  Lou has emersed
his pri/sec in oil for insulation, and has also used ferrite to increase the
coupling.  An article of Lou's was published recently in the TCBA 
Newsletter.  Lou is presently building a new magnifier.

Hope this is helpful,

John Freau