GB408961A - Improvements in circuits for the operation of electrical relays - Google Patents

Abstract

408,961. Valve circuits. GENERAL ELECTRIC CO., Ltd., Magnet House, Kingsway, London, and ESPLEY, D. C., c/o General Electric Co., Wembley, Middlesex. Oct. 17, 1932, No. 28957. [Classes 40 (iii) and 40 (v).] A relay for use in A.C. or D.C. telegraphy or for like purposes is fed by a gas-filled valve and shunted by a condenser in order that the anode current may be started and stopped at approximately' equal values of grid-potential. The gas-filled valve V has a characteristic such that when the grid-potential is becoming positive and reaches the striking potential, anode-current begins to flow and reaches saturation ahnost at once. When the gridpotential is becoming negative, however, anodecurrent would continue to flow, in the absence of the condenser C, until a cut-off potential much lower than the striking potential is reached, so that the operation of the relay, which forms part of the resistance R, would be prolonged and distortion of signals would result. According to the invention the condenser C is made large enough to raise the cutoff value of the grid voltage to a value nearly equal to the striking potential, and also to prevent the valve from cutting off during the negative half-waves of an alternating signal. A low resistance r is included for the protection of the valve against an unduly large rush of current when the valve strikes. Specification 373,383 is referred to.