Induction coil
Videos
An induction coil or "spark coil" is a type of transformer used to produce high-voltage pulses from a low-voltage direct current supply. To create the flux changes necessary to induce voltage in the s
Antique induction coil used in schools from around 1900, Bremerhaven, Germany
Early coil by Charles G. Page, 1838, had one of the first automatic interrupters. The cup was filled with mercury. The magnetic field attracted the iron piece on the arm (left), lifting the wire out of the cup, breaking the primary circuit.
The first induction coil, built by Nicholas Callan, 1836.
Modern automobile ignition coil, the largest remaining use for induction coils
Oudin coil
Videos
An Oudin coil, also called an Oudin oscillator or Oudin resonator, is a resonant transformer circuit that generates very high voltage, high frequency alternating current electricity at low current lev
Treatment of knee by effluvium method using Oudin coil, 1907. The pointed electrode with insulated handle (B), attached to top of the coil, is directed at knee. The patient holds a "ground" electrode (A) attached to the coil bottom. Note operator's other hand (D) adjusting coil.
Oudin electrotherapy outfit. Includes the Oudin coil (right rear), induction coil which powers it (center rear), power panel with mercury interrupter (left rear), and condensing bed (foreground)
A vacuum electrode.
A vacuum electrode in operation showing violet glow