The Turn Of The Century Electrotherapy Museum

Tesla's Table Top Coils...

A few color renderings from blueprints and articles...

Excerpts from Leland I. Anderson's Nikola Tesla:  Lecture Before The New York Academy Of Sciences - April 6, 1897
Twenty First Century Books

Larger photo

Blueprint of H.G. Fischer "H" Tesla Coil - 3600 turns of wire in the secondaries totals.
This bipolar Tesla Coil uses a 1000V transformer and .6 mfd mica condenser.
It uses only a single 1/4" tungsten spark gap.
Of the hundreds of antique Tesla Coils I have experimented with, this is the most efficient I have ever seen,
and I believe its design is close to what Tesla himself was building in the 1890s.

Top view of coils under the case

Side view of coils - posts are 7" between centres

Crackling sparks:
To show the unusual nature of this coil, the unit was powered by only 20 volts AC.  The output on the power transformer - normally
1000 volts - was less than 200 volts.  A barely visible spark gap was maintained less than .001".  Sparks 4" long, seen above, crackled
between the terminals.

At full power, consuming 15 amps, this unit produces nothing short of a flame!

McIntosh Bipolar Tesla Coil
The coarse tapped winding seen on top of the kicking coil is used for the cautery circuit.

3 - 4" Sparks.  This unit operates at a higher frequency than the Fischer X-Ray.

An efficient 3" spark Tesla coil.

A selection of Tesla Coil cross-sections...

(C) Jeff Behary, 2008