Patent GB-753471-A (GB)
Title: Improved arrangement for actuating electric relays in sequence
Inventor: HALLAS LISTER
IPC: H01H63/36
Filed: 1953-04-13
Abstract: 753,471. Counting-apparatus. SOUTHERN UNITED TELEPHONE CABLES, Ltd. April 13, 1954 [April 13, 1953], No. 10020/53. Class 106 (1). In an arrangement for the actuation of a set of electric relays in sequence by a repeated control signal, the relays are in two sets (odd relays and even relays) which are operated alternately by means of odd and even relay lines, a change-over switch being provided to apply the repeated control signal alternately to the two lines. The general arrangement, Fig. 1, comprises a switch p, the makes and breaks of which produce the signals which are passed to a group of relays A, B ... N divided into a set of odd relays A, C ... connected to the odd line wand a set of even relays B, D ... N connected to the even line x. A change-over switch o1 controlled by a relay O connects the lines w and x alternately to the switch p. The relays A, B ... N have a holding line y. The relay O has two separate windings and operating circuits which are arranged so that the relay O is alternately operated and released by the breaking of the switch p. To start the operation the switch W is manually closed so that upon closing of the switch p the relay A is energized and closes its holding circuit at a1, the circuit of one of the windings of relay O at a3 and the preparing switch a2. The said winding of the relay O is shunted by the line s and is therefore not energized until the breaking of the switch p whereupon the switch o1 moves to the lower contact. At the next making of the switch p the relay B is energized to close its holding circuit at b1 and the preparing switch b2 and to open the holding circuit of the relay A at b4. The switch a3 is opened but the first winding of the relay O is held operated over the line U and the switches o1 and p. When the switch p breaks the relay O is released and the switch o1 moved back to the upper contact. The operation proceeds in this way through the relays A, B ... N, the operation of the last relay N preparing a circuit for relay A at n2 so that the cycle of operations restarts. The switch n2 may be omitted and the manually operated switch W may be replaced by a series chain of normally closed contacts opened by any one of the relays A, B ... N. If the encircled contacts in Fig. 1 are omitted each relay A, B ... N will remain energized until the switch n5 is opened by the relay N. In Fig. 2 five relays A ... E each having two windings are arranged in a similar manner to form the units denomination of a counter. The relays control associated lamps 1, 2 ... 0. The lamp 1 is initially lit in readiness for the first closing of the switch p which effects energization of the relay A which closes its holding contact a1 and the preparing contact a2, opens the contact a5 and transfers the contact a6 so that the lamp 2 is lit when the relay O operates at the break of the switch p. The operation continues in this way up to the operation of relays A, B, C, D and the consequential transfer of contacts a7, b7, c7 and d7. Upon the next closing of the switch p, the relay E is operated, lamp 6 is lit and contacts e15, e5 are closed and contact e2 is opened. The contact e5 establishes a shunt connection between the even line x and the odd relay A so that on the next closing of the switch p the relay A is released, contact a5 is closed to establish a shunt connection between the odd line wand the even relay B which is released upon the next closing of the switch p. The operation continues in this way, on the closing of the switch c5 the switch e15 connects the switch p with the change-over switch of the tens denomination of the counter. During release of the relays A ... D the lamps 7 ... 0 are lit in sequence. Printing wheels may be provided. The above-described method of sequential operation of relays may be used to apply in turn each of four wires of a quad to a testing apparatus, Fig. 3 (not shown), or to add impedance in unit steps to a bridge circuit to produce balance, Fig. 4 (not shown).