Re: Magnifier coils
Sent: Thursday, July 17, 1997 4:14 AM
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
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
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,