GB691341A - Apparatus for energizing electrical precipitators and the like - Google Patents

Abstract

691,341. Converting; supply systems for electrostatic precipitators. RESEARCH CORPORATION. March 8, 1951, No. 5633/51. Classes 38 (ii) and 38 (iv). [Also in Group XL (c)] A high D.C. voltage for energizing an electrical precipitator is obtained from a low voltage D.C. source by rectifying the output of an oscillatory circuit fed from the source and the capacitor of which is associated with a thyratron which when fired varies the charge in the capacitor. One circuit described comprises an oscillatory circuit Lal, Ca<SP>1</SP> connected in series with a D.C. supply 11a. The capacitor Ca<SP>1</SP> also forms part of an oscillatory circuit of much higher frequency including an inductor La3 and thyratron Ta so that when the thyratron is fired the capacitor discharges through the circuit and due to the inductor La<SP>3</SP> charges in the reverse sense. The D.C. source and the voltage across the capacitor then causes the main circuit to oscillate. A coil La<SP>2</SP> is loosely coupled to the inductor La<SP>1</SP> to form a step-up transformer the output of which feeds a voltage doubler rectifier and finally the precipitator 15a. The repetition frequency of the pulses fed to the grid of the thyratron to cause the thyratron to fire is preferably equal to the natural frequency of the main oscillatory circuit. In an alternative circuit, Fig. 2 (not shown), the capacitor is connected directly across the inductor La<SP>1</SP> and the D.C. supply is in series with the thyratron. The output may alternatively be obtained from a separate transformer in series with the inductor.