Patent GB-1320572-A (GB)
Title: Electrical programme control apparatus
IPC: G05B19/10
Filed: 1970-07-28
Abstract: 1320572 Program switches S KRATOMI 28 July 1970 [29 July 1969] 36410/70 Heading G3T [Also in Division H3] A program switch, Fig.1, comprises a primary stepping switch 1 having contacts S 1 ..S 6  which close cyclically in succession at intervals of 10 mins. and a secondary stepping switch 2 having contacts S' 1  ---S' 4  which close cyclically in succession at intervals of 1 hour, the switch 2 advancing one step each time the switch 1 completes a cycle. A power supply is connected to terminals X, X'. Primary timing selectors 3 and secondary timing selectors 4 are connected, respectively, to the switches 1, 2. The two input terminals of signal transferers 5 are connected, respectively, to the common terminals of the corresponding pair of selectors 3, 4, the two output terminals being connected, respectively, to a common bus E and the common terminal of a corresponding channel selector 6. The signal transferers 5 are constructed so that their inputs and outputs are electrically isolated from each other and function such that when a current flows between their input terminals their output terminals establish a current path between the common bus E and one of the control channels C 1  --C 5  in dependence upon the position of channel selectors 6. The transferers 5 may comprise induction couplers, electromagnetic relays, photo-electric couplers or electromagnetic couplers consisting of an electromagnet and a magnetism - sensitive semi-conductor switch having a resistance which varies with magnetic field intensity. The program switch may be adapted for controlling a broadcast receiver 22 or recorder 24 and also for controlling the broadcast channels pre-set by manually operated switches 17 as shown in Figs.2, 3. The connecting points between Figs.2, 3 are denoted by references A 1 --A 3 , B 1 --B 3 . Primary switch 7 has twelve contacts S 1 --S 12  closing at 5 min. intervals and secondary switch 8 has twelve contacts closing at intervals of one hour. The primary and secondary timing selectors have references 9, 10. A.M. -P.M. selectors 12 in co-operation with automatic A.M. - P.M. changeover contacts 11 and the selectors 10 make the operating cycle have a period of 24 hours. The signal transferers have references 13. Selection of OFF, MONITORING, RECORDING is made by selectors 16. A rotary switch 18 for controlling the twelve broadcast channels is driven by a motor 41 controlled by a connecting relay R1 and disconnecting relay R2 operating contacts r 1-1  and r 2 , respectively. The relay R1 also serves to connect the receiver 21 through contact r 1-2 , the receiver being disconnected by a relay R3 through contact r 3  -1 . R 4  is a holding relay for the receiver and controls contact r 4 . Relay R3 also disconnects the recorder 24 through contact r 3-2 . Relays 6, 7 serve, respectively, to connect the recorder and hold it. The lines W, W', Y, Y', Z, Z' are connected to a voltage supply. Auto - Manual - Off selectors 20 are linked together and PB denotes a push-button for manually energizing the motor 41. The programming board, Fig. 4, comprises sets of knobs and dials each having twelve positions corresponding to the broad - cast channels. 25 denotes a dial of a primary timing selector 9; 26 denotes a dial of a secondary timing selector 10; 27 denotes a knob of an A.M. - P.M. selector 12; 28 denotes a dial of a broadcast channel selector 17; 29 denotes a knob of a selector 16; 30 denotes pilot lamps to indicate "monitoring" and 31 denotes pilot lamps to indicate "recording".