The spark gap tesla coil is nothing more than a spectacular looking transformer. Let's face it; a tesla coil has no great purpose other than to show off. The inventor of the Tesla coil Nikola Tesla, wanted to transmit energy through the air. The efficiency of his invention was anything but lousy. Classic demonstrations of a Tesla coil always produce very long visible discharges through the air of high-frequency alternating electric voltages. With the construction of my Tesla coil I wanted to use the electromagnetic field to illuminate fluorescent tubes. In the video below you can see an illuminating flourecent tube becuase of the strong electromagnetic field of the coil.

As a high voltage input source I used a two stage high voltage generator from a stun gun. The stun gun is operated with 18 V. I removed the second stage of the stun gun electric board and it is not used. In the schematic this part is described as AC MAINS. The primary circuit consists of a so-called spark gap , three capacitors connected in series of 50nF and a primary coil of about 5 1/2 turns. The secondary circuit is about 750 turns. The cylinder of the secondary coil is 15 cm high and has a diameter of 50 mm. The toros consists of a hollow stainless steel ball.

The housing around the spark gap is housed in an old wooden coffee grinder. The metal construct was soldered from brass and the brazing - method. The insulating parts of the housing are made of ceramic from fuses and tiles. The upper tile with the brass frame forms the ground of the secondary circuit of the tesla coil. All conductive parts of the primary circuit are made of copper. Copper screws I have broken out of old circuit breakers. The cylinder of the secondary circuit is a PVC sewer pipe.

A project not finished

After some hurdles in the construction time, because of missing material I am still not finished. When finished, the Tesla coil should be a Tesla lantern. As you may have noticed, the arc emits a very bright and white light. The color temperature of an arc is about 4500-5000 Kelvin. Focused through a lens it should be an unconventional arc flashlight. Four holders for four fluorescent lamps and a handle with an on-off-switch should be attached to the housing. The secondary coil should be larger and have 1200 turns. The coil is to be powered by an 18 volt battery from a cordless screwdriver. Currently the circuit is powered by two 9 volt batteries connected in series.