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
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
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