GB665391A - Improvements in stopping circuits of rotary switches having a marking multiple common to several marking devices - Google Patents

Abstract

665,391. Automatic exchange systems. COMPAGNIE INDUSTRIELLE DES TELEPHONES. April 20, 1949 [April 20, 1948], No. 10407/49. Class 40 (iv). In a register-controller system in which selectors hunt over a common marking multiple, crossed connections arising due to the operation of two test relays in series with two register batteries are prevented by the inclusion in each register of a second two-winding relay which in such an event causes the release of the two test relays. If the two test relays A1, A2 operate when the selectors S1, S2 are positioned as shown in Fig. 3 the auxiliary relays B1, B2 are energized over their upper windings. It is assumed that one relay B operates before the other, say B1 before B2. The following circuit is then completed: positive pole of U2, back contact and upper winding of B2, A2, brush 402 of digit switch D2, wire m2, b11, brush CS1 of selector S1, lower winding of B1, rectifier R1, brush 401 of D1, wire m1, b23, brush CS2, negative pole of U2. The lower winding of B1 has a resistance high enough to prevent B2 being energized in series therewith, and to bring down A2. Relay A1 is also released, being open-circuited at back B1. The stopping relays C1 and C2 are sufficiently slow-to-operate to remain down during the momentary operation of A1, A2 and the two selectors continue hunting. When the normal test circuit of one selector, say S1, is completed, A1 pulls up and removes the short-circuit from the upper winding of B1. B1 then operates but opens its own circuit at its back contact and continues to vibrate, A1 holding during the breaks due to the presence of condenser X1. Relay C1 then pulls up and stops the selector. Reference has been directed by the Comptroller to Specification 651,264.