GB501395A - Improvements in control systems for selectively connecting rectifiers to load circuits - Google Patents

Abstract

501,395. Electricity supply. WESTINGHOUSE BRAKE & SIGNAL CO., Ltd., and STEVENS,S.A. Aug. 30, 1937, No. 24945/38. Divided out of 492,744. [Class 38 (iv)] Selecting sources in service.-In an arrangement in which a number of load circuits P4-P7 are supplied from a number of rectifier sources R6, R7 of such capacity that each can only supply one of any of the load circuits, means are provided whereby a rectifier can be connected to any load provided it is not already supplying another load circuit. In the example shown, each of the load circuits is arranged for connection to either of the rectifier sources R6, R7 through one of two contactor switches 41, 45 ; 42, 46; 43, 47 ; 44, 48. The coils of the switches are 'energized from busbars C1, C2 connected to a transformer T and a pair of contacts such as 32, 28, control the energization of various sections of the busbars. Closure of a control switch 53, provided for each load circuit, into one of its two operative positions causes energization of the corresponding contact coil such as 22 or 49 under the control of a further controller 36. Closure of the contactor switch such as 41 causes opening of contacts 32, 28 and closure of a switch 56 which thereafter permits a control switch 54 coupled to the switch 36 to act on transformers supplying the rectifier such' as R6 so as to vary the current as required for " striking " or " burning in " and " running " of cinema projector arcs forming the loads. Opening of contacts 32, 28 opens the supply circuits of all other contactor coils controlling connection to the same rectifier and also of signal lamps such as 55 which, when energized indicate that the corresponding rectifier is not loaded. Movement of the control switches 53 of other loads to connect them to the loaded rectifier produces no effect and one only of these can be connected to the other rectifier, thereby opening contacts in the coil supply circuits of the lower set of contactors to prevent connection of further load circuits.