An Oudin coil, also called an Oudin oscillator or Oudin resonator, is a disruptive discharge coil, that is a transformer designed to produce high voltage arcs and discharges, similar to a Tesla coil. It was invented by French physician Paul Marie Oudin and physicist Jacques d'Arsonval around 1899.
The device is a high frequency current generator which uses the principles of electrical resonant circuits. It produces an antinode of high potential. The high-voltage, self-regenerative resonant transformer has the bottom end of the primary and secondary coils connected together and firmly grounded.
Oudin coils generate high voltages at high frequency. Oudin coils produce smaller currents than other disruptive discharge coils (such as the later version of the Tesla coil). The Oudin coil is modified for greater safety.