The Turn Of The Century Electrotherapy Museum
(C) Jeff Behary 2007

Low Voltage "Electronic" "Solid State" Tesla Coil :)
(Okay, not really)

The coil is wired as follows, a completely normal Tesla Coil circuit aside from the output of the power transformer:
120V input to "high voltage transformer".  In reality, the output is only 240V.  Its an auto-transformer from a mercury vapour lamp.
The 240V is current limited with a choke coil - a small Violet Ray electromagnet ("self-induction") coil.  Across the 240V transformer is a 1 mfd capacitor.
Two outputs for a Tesla Coil or Induction Coil are in the front on the left, and are wired in series with a spark gap to the capacitor.

Side view of gap.  The Tungsten Contacts are seen between the vertical plates.

Top view.  Approx. actual size.

Side view.  Spark Gap, General Electric 600 VDC 330 VAC 1 MFD Cap, Oil-Filled.

Appearance of Bovie Spark Gap...Adjustable by a fine tooth gear mechanism, can be adjusted from
less than .001" upward.  For this tank circuit, around .001" is used.  Even with only 240V sustaining a spark
gap is not problem.  (It does get more difficult at 110V, which is why 240V are used here)

Gap slightly opened...

Hot discharge!

Complete Test, shown here with a small Ford ignition coil.