TESLA
Energising
Laboratory
The physics behind the sparks: coils, fields, induction and alternating current — explained plainly and then technically.
Two coupled coils are tuned to the same resonant frequency, so energy pumped from primary to secondary over several cycles produces a voltage rise far greater than the turns ratio alone. The visible discharge is air breaking down at the terminal.
Ohm’s law, the field of a solenoid, Faraday’s law of induction, sinusoidal alternating voltage, the transformer turns ratio, and the synchronous speed of a polyphase motor — six relationships that between them explain the whole electrical system.
Do not attempt to build or operate a high-voltage coil without proper training. The circuits described here can kill.