Lightning Bulb

A transformer capable of high voltage. An used ignition coil of a small car (Maruti 800 ) is used.

This is to control the shape of the AC current. To convert smooth sinusoidal waves into square pulsating current on low power setting.

Polypropylene capacitor to limit current in the circuit for safety purposes. 225J400V - stands for 2.2 x 10-5 F. Can be any value as long as it is 10-5 F.

Since glass has better permittivity than air. The sparks move relatively conveniently on the surface of the glass and put up a beautiful display. The terminals of the light bulb is connected to the neutral and the high voltage wire is placed on top of the bulb with a small gap. 

To hold the bulb in place

Thick insulated wires to prevent unnecessary arcs.