Schematics of DC Spark Powered Tesla Coil System
(Place mouse pointer over part of schematic to click on picture hyperlinks)

Planned DC Power Supply Circuit

Note the filter choke in the circuit above is for the power factor correction purpose only.  Smooth, low ripple DC output is not required for the Tesla coil operation, however with the available components I already have on hand, it is one of the way to keep single phase 240V AC power factor to about 0.9 and the current waveform will look more like sine instead of spikes.  Overall weight is about 400 pounds


Planned DC Resonant Tank Capacitor Charger Circuit

Homemade 1.6 H reactor with 1/4" air gap in its core and about 1,600 turns of #18 wire layered with LDPE insulating sheet.  The core came from a burned out GE 2400V:240/120V, 3kVA pole mount transformer.   There was two rolled iron core, but only one was needed.  I adjusted the desired inductance of about 1.6 H by cutting air gap into the core.  It was about 10.6 H before cutting air gap. 

Overall weight is about 400 pounds with DC power supply above, split into two 19" rack roll-around cabinets.


Planned Tesla Coil

Three German made 0.02 uF, 200kV Mica capacitors are connected in parallel for total of 0.06 uF.  They have over 200 pounds of thermal mass that could hopefully help with longer run time without overheating problem.   Extra high voltage rating will also give tank capacitor more margin for harsh Tesla Coil operation and hopefully will not fail for a lifetime. 

The secondary coil winding on 11" diameter PVC duct pipe with bottom sealed and then place it inside another 12" diameter PVC duct with bottom also sealed.   The transformer oil of less than 2 gal. will be filled in between two PVC pipes where winding will be insulated from corona and then removable top seal is bolted in place, which is part of 11" diameter PVC pipe.  The air is not trapped inside the 11" PVC pipe, but has hole on top seal lid for that purpose and oil will not leak out even if it's up side down.  Cork gasket is the best way to seal oil inside with no leaking problem.

The RPG (Rotary Spark Gap) is made out of 1/2" by 12" diameter cloth grade phenolic fitted with 0.375" trgent  electrode rods in six places.   The disc is mounted directly on 24V, 6,250 RPM 1/3 HP DC motor (World War II era motor).  The BPS rate is variable from 100 to 600 per second.