Improvements in electrical systems for remote control

Abstract

Abstract 555,664. Selective control. GENERAL ELECTRIC CO., Ltd., and COLLYER, J. E. Aug. 19, 1942, No. 11639. [Class 40 (i)] In a system of selective control over power mains (e.g. for ring- ing time bells) in which the selective signals are of different lengths means are provided for delaying the transmission of the signals to different extents after an initiating operation so that all bells are operated at the same time, say 30 seconds, after such operation. The transmitting operator moves a selecting switch HS and then a push-button SK. On the operation of the latter, ST pulls up (relay N being normally operated) and locks, releasing a normally energized relay T. Motor TE thereupon drives the associated switch TE1 in search of a contact marked byHSl. When this contact is reached, T pulls up and stops the switch. The time occupied by this operation is complementary to that required subsequently by the bell-selecting switch. On moving off normal, switch TE1 prepares a circuit for S which is completed when T re-operates. Circuits are thus made for motor TS of switch TS1 and for sending, by means not shown, a voice frequency signal over the power line L, N. In response to the signal impulse, TR at the sending end connects up motor CS of switch CS1 and R at the receiving end connects up the synchronously running motor OS of switch OS1. When switch CS1 moves, N is released. In a position corresponding to the starting terminal STA of switch CS1, off-normal contacts LS4 and OS4 change over and interrupt the driving circuits. After 3 seconds, however, switch TS1 releases S to terminate the signal impulse and stops. and on the relapse of TR and R the switches CS1, OS1 are driven again until CS1 reaches the terminal marked by switch HS. Relay A thereupon operates over a centring cam set CS6, locks itself, releases ST, sends a signal over the power circuit and makes a circuit for driving TS1. Relays TR, R then stop the switches CS1, OS1 and R in addition energizes the selected bell. When TS has moved a predetermined distance, A is released to terminate the second signal and, on the relapse of TR. R, the bell is cut off, the switches CS, OS are restored to their home positions. The resulting operation of N drives TS1 to its home position.

Inventors

No inventors recorded.

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