GB1004675A - Electrical gate circuits - Google Patents

Abstract

1,004,675. Diode gating circuits. WESTERN ELECTRIC CO. Inc. April 5, 1962 [April 14, 1961], No. 13102/62. Heading H3P. A gate circuit comprises a series arm having two separate paths 40, 47 connecting an input terminal 26 to an output terminal 28, each path including a pair of oppositely poled asymmetrically conducting devices 37, 42 and 43, 48; and a plurality of shunt arms connecting each path to ground, at least one of each plurality including an asymmetrically conducting device 74, 77 and another one of each plurality including a bias source 111, 112 for opening or closing the gate; the two paths forming a balanced bridge with respect to the source. In the conducting state of the gate, diodes 37, 42, 43, 48 conduct and the characteristic impedance is determined by the shunt impedances 64, 65, 69, 70. Capacitors 80, 81 and C.R. networks 33, 35 provide compensation for the reactance of the components of the gate. In the non-conducting state of the gate diodes 74, 77 are conducting, and diodes 37, 42, 43, 48 are held non-conducting by the bias developed across C.R. networks 84, 85 and 86, 87. The balance of the bridge network formed by the two paths with respect to the bias source 111, 112 is determined by the values of resistors 38, 41, 45, 46 in the conducting state, and by resistors 39, 43, 44, 49 in the non-conducting state. The arrangement may be modified for balanced input signals by the provision of a similar gating circuit in the other series arm of the circuit, Fig. 1 (not shown). Specifications 973,733 and 1,001,462 are referred to.