Interrupter
Frequently, the interrupter is used in conjunction with an inductor (coil of wire) to produce increased voltages either by a back emf effect or through transformer action.
The largest industrial use of the interrupter was in the induction coil, the first transformer, which was used to produce high voltage pulses in scientific experiments and to power arc lamps, spark gap radio transmitters, and the first X-ray tubes, around the turn of the 20th century.
The physician Golding Bird designed his own interrupter circuit for delivering shocks to patients from a voltaic cell through an induction coil.
A modified version of the interrupter was produced by Henry Letheby which could output only the make, or only the break currents by a mechanism consisting of two spoked wheels.
[1][3] Other early interrupters worked by clockwork mechanisms or (non-magnetic) reed switches operated by motion of the patient's limbs.
Description : The prongs at the end of the pivoted arm dip into mercury filled recesses. This completes a circuit which energises a coil around the iron pivot arm and functions as an electromagnet . The magnetic polarity is so arranged that a permanent magnet underneath the arm then repels the pivot arm and causes the circuit to break, but the prongs at the other end of the pivot arm then close an identical circuit at that end and the procedure repeats endlessly. The output of the interrupter is fed to an induction coil which greatly increases the voltage applied to the patient by transformer action. [ 1 ]