Ignitron Circuits

Author: E.E. Kimberly

In Fig. 27-37 is shown a full-wave heavy-duty rectifier circuit with two ignitrons and two thyratrons controlling their igniter circuits. If current is allowed to flow backward in the igniter circuit, that is, from the cathode to the igniter, the igniter will be damaged. If a thyratron is not used to control the igniter current, some other type of rectifier, such as the copper-oxide rectifier described on page 342, must be used; The grid-control transformer is sometimes designed to give a sharp-peaked voltage output, so that the instant of firing of the thyratron may be more accurately controlled. The ignitron plate circuit and the ignitron are in parallel. When the ignitron fires, the thyratron is almost relieved of plate voltage and ceases to conduct. If, however, the ignitron fails to fire, the full peak of plate voltage is permitted on the thyratron; and damage will certainly occur unless the circuit is protected by a fuse or a current-limiting resistor.

Fig. 27-37. Two Ignitions for Full-Wave Conduction With Thyratron-Controlled Igniter Circuits