Specifications of my coils

4" coil

...................primary coil...................

.................secondary coil................

For the pictures strike1.jpg through strike15.jpg the following additional parts were used.

Topload is a 6" X 24" Styrofoam disk with the edges rounded off and covered with aluminum foil duct tape. The primary capacitor is a MMC type composed of 4 series strings of 14 Panasonic 56nf 1600V polypropylene pulse caps in parallel for a total capacitance of 16nf. Each individual capacitor is paralleled with 2 5.1megohm carbon film resistors in series. The power source is a 5KVA distribution transformer current limited by a welder with movable shunts. The welder shunts are all the way in and the secondary open. The spark gap is a SRSG, 120 BPS, 3600 RPM with two flying electrodes and two stationary electrodes that are made of solid brass 1/2" in diameter and have hemispherical ends. Total gap distance is .040". Rotor is 1/2" thick X 7" diameter G-10 with the electrodes on a 6" circle.

Other toploads used with this coil are:

4" X 21" aluminum dryer duct with aluminum flashing center, covered in aluminum foil duct tape, 4" X 16" aluminum dryer duct with Styrofoam center, covered in aluminum foil duct tape.

Other primary capacitors used with this coil are:

10nF EMMC (same Panasonic caps from Digikey).
The 10nF EMMC in parallel with the 16nF MMC.
24nF (two sections of 48nF 33KV radar pulse capacitor in series).
One section of 48nF radar pulse capacitor.
13.8nf rolled polyethylene / aluminum flashing in oil.
16nf rolled polyethylene / aluminum flashing in oil.

Other power sources used with this coil are:

15KV 30mA Neon sign transformer.
15KV 60mA Neon sign transformer.

Other spark gaps used with this coil are:

Single static blown air gap with two 3/4" diameter X 2 1/2" long brass round stock on threaded rods (3/8" 16 tpi, brass) for adjustment. Blown by 5 HP 2 stage air compressor. The best results were obtained with a gap setting of 7/16". This is a very noisy gap and the air compressor running all the time does not help with that. Hearing protection is a must.
SRSG 120 BPS, 1200 RPM, 6 flying and 2 stationary electrodes. The electrodes are 1/8" pure tungsten rods through 3/8" brass rods with the tungsten silver soldered on one end to prevent the press fit tungsten rods from coming out. The brass rods are press fit into six 3/8" holes in a 7" diameter X 1/2" thick G-10 rotor. Only friction is used to hold the rods in place. The stationary electrodes are 3/4" diameter brass round stock with hemispherical ends. The ends have a 1/8" tungsten rod installed in them that sticks out about 5/16" past the brass. The stationary electrodes are mounted at an angle to the flying electrodes and the spark gap is supposed to be between the rounded ends of their tungsten rods and the sides of the tungsten rods in the flying electrodes. Phase adjustment on this gap is by means of curved slots with the machine screws that hold the disk to the hub going through them. This gap was built into an air conditioner condensing unit housing and utilized the 1/4 HP permanent split capacitor condenser fan motor from the air conditioner. The motor mount was used as is, and the fan shroud is the explosion shield. This means that the spark gap rotor runs in the horizontal plain.

Medicine coil

......................primary coil......................

..................secondary coil................

..................top load..............

1" X 7 1/4" Styrofoam disk with rounded edges and covered with aluminum foil tape.

..................power source.............

6.5KV 7.5mA current limited transformer from a small copier power supply rectified by its original high voltage rectifier. One side of the secondary is grounded.

................tank capacitor.........

MMC consisting of four 56nF 1600V Panasonic polypropylene pulse capacitors in series with each capacitor paralleled by two 5.1megohm carbon film resistors in series. One end of the tank capacitor is grounded. The other end connects to the high voltage rectifier and one side of the spark gap. The other side of the spark gap is connected to the primary coil. The other side of the primary coil returns to ground.

..................spark gap..............

The spark gap consists of two 1 1/4" diameter solid cast copper balls drilled and tapped for 3/8" 16 tpi mounting bolts used for gap adjustment. The gap is cooled by a small fan from a microwave oven. The gap runs best at a setting of about 1/8".

The big coil

.................secondary coil................

...........no other parts exist for this coil yet..........

..............it has never been fired............