| 摘要 |
<p>1,029,385. Automatic exchange systems. STANDARD TELEPHONES & CABLES Ltd. Aug. 4, 1964 [July 24, 1963], No. 30563/64. Heading H4K. Remanently latching relays in matrices of a multi-stage relay selector are energized over one set of co-ordinate wires in accordance with a mark extended from the preceding stage and a mark extended from a route determining marker (not described in detail), and are released by a reverse energization, the release of a cross-point relay in one stage connecting up the release circuit for the subsequent stage. Matrices A and B are illustrated and a marker such as MB determines which of the relays KB and which of the outgoing links CLB to CLA is to be used. A relay TB is operated during setting up to sever the forward links from earth and to disconnect a set of co-ordinate release wires in the matrix from negative potential. On energization of a cross-point relay one of its contact sets connects the relay to the co-ordinate wire of the release system and another of its contact sets further severs the forward link from earth. Since the relay is latched by remanent magnetism the marker MB can retire and release relay TB. Release of the relay is by reverse energization over the made contact of the relay and a contact of relay TB. When the relay in one stage falls back it connects the link to earth so that the relay in the next stage is reversely energized to effect release, and so on. While a marker is occupied in setting up a call over a matrix, relay TB or TA is energized and no release is possible for any cross-point in the matrix until the marker retires.</p> |
