GB783922A - Improvements in or relating to high voltage regulating systems for electrostatic precipitators - Google Patents

Abstract

783,922. Measuring X-rays. RESEARCH CORPORATION. July 15, 1955 [Aug. 24, 1954], No. 20556/55. Class 40 (3). [Also in Group XXXV] In a system for maintaining the sparking rate in an electrostatic precipitator constant (see Group XXXV), the intensity of X-radiation generated in one or more electrodesupplying rectifier valves, such as 8, as a result of voltage pulses due to electrode sparking, is compared with that from a standard radioactive source 32, the comparison being made in Geiger counter detectors 28, 30. The pulsed outputs of the counters, of frequency proportional to the radiation intensity, are applied over pulse-integrating condensers 40, 38 respectively to the grids of valves 44, 42 respectively, whereby the relative currents in opposed relay windings 52, 54 in the valve anode circuits depend on the sense and magnitude of the sparking rate deviation from the optimum value set by source 32. A sufficient deviation causes relay contact 56 to make with one or other of contact X, Y, whereby the supply to the precipitator electrodes is correctively adjusted. A resistor 46 and/or the source itself may be adjusted to set the said optimum value. In a modification, Fig. 2 (not shown), the counter outputs are directly applied to the valve grids, each of which is capacitatively coupled to the anode of the opposite valve. The circuit functions as a freerunning multivibrator with negligible valve anode current if the sparking rate deviation is small, while a large deviation causes one or other of the valves to continuously conduct in one of the bistable conditions of the circuit.