Patent GB-376363-A (GB)
Title: Improvements in or relating to electrical signalling systems
IPC: H04Q3/04
Filed: 1931-04-10
Abstract: 376,363. Electric signalling systems; optical sound records. ASSOCIATED TELEPHONE & TELEGRAPH CO., 1033, West Van Buren Street, Chicago, U.S.A. April 10, 1931, No. 10671. Convention date, May 13, 1930. [Classes 40 (i) and 40 (ii).] Electric switching operations are controlled by means of a photo-electric cell operated from a moving film the markings of which are such that the cell is caused to transmit a series of current impulses to operate the desired relay in a control group. The arrangement shown employs a counting relay chain adapted to control relays of a plurality of different groups, the operation of a relay in any group effecting the de-energization of any previously operated relay in the same group but producing no effect on relays of other groups. The invention is described as applied to equipment used in producing sound motion pictures. A group of relays 11 .. 14 is employed in controlling the output volume of the sound amplifier, and relays 21 .. 29 comprise a second group of which relays 21, 24 control the intensity of the light produced by the red, blue, amber, and white lamps shown, and relays 22, 23 and 25 .. 29 may be used to control further the lamps or perform other circuit switching operations. A group of counting relays 39 .. 64, some of which are not shown, is provided for the selection and operation of a relay in either of the other groups, in accordance with the number of impulses transmitted to the counting relay group. Assuming first, that a section of the film to transmit one impulse passes the photoelectric cell. This causes relay 4 to energize, whereby relays 5, 39 are energized. Relay 39 locks up and energizes relay 40. After the first impulse relay 5 restores, though slowly, whereby circuits are complete for the windings of relays 1, 11. Relay 1 energizes the slowto-operate relay 2 and the relay 3. Relay 3 operates immediately to open the locking Circuits of any relays in the group 11 .. 14, but is de-energized when relay 2 operates, the latter locking through the contact of relay 5. Relay 11 acts to bridge the resistance 100 across the loud-speaker leads whereby the volume output is diminished. Relay 2 completes a circuit to energize relay 75 which opens the locking circuit of the pair of counting relays 39, 40. The de-energization of relay 39 removes negative battery from conductor 85 whereby relay 2 is de-energized causing also the release of relay 75. In a similar manner a code of two, three, or four impulses would effect the operation of relay 12, 13, or 14 respectively. Assuming now that a code of five impulses is transmitted to relay 4, the first of these impulses will operate relays 39, 40. Relay 5 being slow acting does not de-energize between the series of impulses so that relays 1, 2, 3 do not operate until the termination of the series. Upon the second energization of relay 4 a circuit is complete for the operation of relay 41, which locks up and causes the energization of relay 42. The third impulse similarly causes the operation of relays 43, 44 (not shown), and so on, so that the five impulses cause relays 39 .. 48 inclusive to be operated. When relay 5 de-energizes a circuit is complete through the winding of relay 6, conductor 84, upper armature of relay 48, conductor 89, and winding of relay 21. Relay 21 operates to modify the intensity of the light from the lamps shown. Relay 6 energizes the slow-to-operate relay 7 and the relay 8 so that the latter operates momentarily to open the locking circuits of previously operated relays in the group 21 .. 29. Relay 7 at its uppermost springs acts to operate release relay 75 whereby the counting relays are released and subsequently relays 7, 75 are released.