GB370551A - Circuit arrangement for switching on and off subscribers' stations in telegraph installations - Google Patents

Abstract

370,551. Type-printing telegraphy. SIEMENS & HALSKE AKT.-GES., Siemensstadt, Berlin. Feb. 6, 1931, No. 3857. Convention date, Feb. 7, 1930. [Class 40 (iii).] The transmitter and receiver at each of two stations connected through an exchange are rendered operative, in response to an interruption of the normally flowing current, by means which include a pair of oppositely-directed rectifiers at each station. In the idle position, the motor-control relays U, U<1> at the subscribers' stations TS, TS<1> are energized by current from the exchange batteries SB, SB<1> through the rectifiers VS, VS<1>. Windings I of differential relays ER, ER<1> overpower windings II, and armatures er, er<1> take up the positions shown, artificial lines Nt, Nv, Nt<1>, Nv<1> being provided. When TS breaks circuit by means of his calling key ET, magnet U releases and cuts in the motor A. Winding I of relay ER being disconnected, winding II moves armature er to the left, reversing the current in sending- on relays SR, SR<1>. Armatures sr, sr<1>, throw over, energizing slow-release relays R, R<1> and cutting out at r, r<1>, the batteries SB, SB<1>. The reversed current from batteries TB, TB<1> is able to flow through the alternative rectifiers Vt, Vt<1>, so that windings I are energized and armatures er, er<1> are held to the left, the slowrelease relays V, V<1> finally cutting out at v, v<1> the motor-control relays U, U<1>. Signals are now sent by transmitter-contact S, by interruption of the normally flowing current, and are passed on by armatures er, sr<1>, the slow-release relays V, V<1>, R, R<1> holding on throughout. Release is effected with a prolonged interruption by means of key AT.