GB743566A - Improvements in electric pulser circuits - Google Patents

Abstract

743,566. Pulse generator circuits. RESEARCH CORPORATION. Sept. 3, 1953 [Sept. 3, 1952], No. 24370/53. Class 40 (6). A pulse generator comprises a pulse-forming network including a capacitive element and a unidirectional switching device which periodically connects the capacitive element with a pulse transformer feeding the load circuit. Fig. 1 shows a high voltage pulse generator for modulating a magnetron 17 in which the pulse forming network 12 is charged from a D.C. source 6 via inductor 8 and diode 10 and is periodically discharged through the primary of the pulse transformer 14 when thyratron 16 is fired by a trigger pulse derived from the conventional low power pulser 22. The thyratron grid circuit impedance is kept very low, of the order, e.g. of 50-100 ohms, by feeding the trigger pulse from a non-inductive cathode load resistance 20 in the trigger pulse generator circuit via the 1 : 1 isolating transformer 21 to the grid of the thyratron 16. Damping diodes 18, 19 reduce the effect of reverse polarity pulses and any transients which may occur. Fig. 2 shows the application to an electrical precipator 24 in which high voltage pulses are applied to the central electrode 26 from the pulse transformer 14. A rotary switch 34 driven by a motor 36 switches the pulse to the spark gaps of similar sections of adjacent precipators and the motor 36 is synchronized with an alternator 38 which provides the trigger pulse for thyratron 51 in the low power pulser which fires thyratron 16 in the main pulse generating circuit. In this way the firing of thyratron 16 is synchronized with the switching of the rotaty switch 34. Thyratron 16 is of the high power type having an internal hydrogen reservoir and a heater which may be adjusted in voltage by circuit 48. A hold-off diode 46 is provided. Specification 660,328, [Group XXXV], is referred to.