GB423725A - Circuit arrangement for effecting switching operations by means of current impulses of short duration - Google Patents

Abstract

423,725. Light current relays. BRONEE, T., 1, Kopischstrasse, Berlin. Sept. 19, 1934, No. 26961. Convention date, Sept. 26, 1933. [Class 38 (v)] [See also Group XXXVIII] Relays adapted to be operated by weak current impulses of short duration, particularly for the actuation of signals, counting mechanisms and the like by moving vehicles, have contacts which are caused to adhere together artificially by burning in such a manner that they remain in contact beyond the duration of the current impulse, the contacts being afterwards separated by the impacts of a hammer or vibrating mechanism. As shown in the Figure, the current impulses, which may be caused to emanate from a coil 1 on the passage of moving vehicles, are received by a relay A the coil 3 of which momentarily brings contacts 4 together on the first impulse. Immediately the contacts 4 engage a condenser 5, which has been charged by a battery 6, discharges across them and so fuses them temporarily together. The closing of the contacts 4 sets into operation a train of relays B .. D, of which the relay D completes at contacts 19 a controlled circuit fed from a transformer 21 across which signal lights 22, counting mechanisms 23 or further relays 24 may be connected. The controlled circuit also energizes an electromagnet 25 operating a vibrating hammer 26 which by striking either the casing of the relay A or the contacts 4 themselves, forces them apart in readiness for a subsequent operation. A thermal switch F is included in the circuit of coil 24 to interrupt its circuit and so reinforce periodically the blows of the hammer 26. If the contacts do not separate the whole system is ultimately cut off on operation of a slow-acting thermal relay E and switching-off relay G. The relay C is given a slow action by a series inductance 14 which with the relay coil 13 is bridged by resistance 15.