GB961501A - Improvements relating to supply circuits for thermionic electron discharge tubes - Google Patents

Abstract

961,501. Supply circuits for discharge tubes. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. April 2, 1963 [Jan. 18, 1962], No. 1923/62. Heading H2H. [Also in Division H3] The heater supply to a thyratron is regulated inversely to its anode current so that the sum of the anode and heater supplies is limited. The primary of a transformer T3 which supplies the heater is series - connected across the mains supply with a booster transformer T2 whose secondary is also fed from the mains supply through a regulator comprising a variable choke T4, the position of its tapping being controlled by a servomotor M1 having field coils F1, F2 controlled respectively by switches P1/1, P2/1. The output from the choke T4 is also supplied, through transformer T1 and rectifier bridge RCT, to one coil L2 of a differential moving coil relay MCR whose other coil L1 is fed from a resistor R connected in the earth return lead of the HT supply for the thyratron. Normally, the armature M of the relay MCR lies midway between the fixed contacts S1, S2, but when the ratio of anode current to heater supply departs from a predetermined range the armature M engages one or other of the contacts S1 S2 to close the corresponding switch P1 or P2/1 (through energization of the coil P1 or P2), thus causing motor M1 to alter the setting of the heater regulator T4 until balance is restored.