GB361071A - Improvements relating to the control of selecting switches such as used in automatictelephone systems - Google Patents

Abstract

361,071. Automatic exchange systems. SIEMENS BROS. & CO., Ltd., Caxton House, Tothill Street, and PATTERSON, W. G., 68, Eltham Road, Lee, both in London. Oct. 20, 1930, No. 31401. [Class 40 (iv).] In bi-directional group selectors which are set under the control of relays in a common control circuit, the release magnet is controlled directly over the test wire. In one arrangement, the release magnet is connected to the test wire when the switch moves off-normal and is short-circuited by the holding potential. A single individual relay when operated associates the switch with the control circuit and when released switches through the connection. In a second arrangement for use in a register-controller system, the switch restores on the relapse of the release magnet, which energizes over the test wire when the switch is taken into use. No individual relays are provided, and the connection is switched through at the preceding first selector. Specification 263,514, [Class 40 (iv), Telephones &c.], is referred to. First arrangement, Fig. 1. Relay C energizes over the c wire when the selector is seized and connects relay X in series with itself, thus marking busy the control circuit and the associated selectors. Impulse relay A energizes over the incoming b wire, connecting up sluggish relays V, D, and impulses are repeated to the vertical magnet VM at contact a1. Relay P pulls up at the first impulse and relay D holds at back contact a3 until the end of the train, and then falls back and closes the hunting circuit for the rotary magnet RM. Test relay T upon operation opens the holding circuits of relays C, X to complete the connection and release the control circuit, while a circuit exists over off-normal contacts k for the release magnet ZM, which however is short-circuited over the test wire as long as the conversation continues. Second arrangement, Fig. 2. When the selector is seized, the back-acting release magnet ZM energizes over the c wire and connects relay ST in series with itself, marking busy the control circuit and the associated selectors and connecting up sluggish relay D. The magnet DM advances the associating switch into engagement with the selector, and relay TC energizes. Impulses are received over the b wire by relay A and are repeated to the vertical magnet VM at contact a1. Relay P pulls up at the first impulse and relay D holds at back contact a2 until the end of the train, and then falls back and closes the hunting circuit for the rotary magnet RM. Test relay T upon operation causes the relapse of relay ST to release the control circuit, but the release magnet ZM remains locked throughout the conversation over rotary off-normal contact w1. The talking connection is completed by the operation of relay WC at the preceding selector when all the impulse trains have been sent.