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

9" Pancake Coil Testing Photos:
Initial Tests for a Rotary Spark Gap 1 KW Pancake Coil

Discharges extend over 12" for the test...however the
coil must be oil-insulated to test on full power and with the spark
gap completely opened!

Detailed photo of discharge seen above...

Click here for a movie of the test...

Click here for an approximate actual size photo...

The rotary gap makes a big difference!

As the power increases, arc-overs begin to occur...

Detail of arc-over.

Rotary Spark Gap:
3600 RPM Fan Motor with 80 Teeth 1/8" Thick Stainless Steel Rotary Electrode
Two 1/8" Thoriated Tungsten Stationary Electrodes
9600 Breaks per second!