GB1264769A - - Google Patents

Abstract

1,264,769. Road traffic signals. REMOTE CONTROLS CORP. 2 Oct., 1970 [2 Oct., 1969], No. 47053/70. Heading G4Q. A system for controlling traffic in two phases A, B at an intersection in a sequence determined solely by a recycling timer comprises a clock 30 operating on the 60 Hz mains and supplying a one pulse per second signal at its output 32. Output 32 is connected to a dividing circuit 34 supplying signals sequentially at its terminals 0 ... 9 at 1 sec. intervals. Terminal 9 is connected to a dividing circuit 38 which similarly supplies signals sequentially at its terminals at 10 sec. intervals and likewise a dividing circuit 42 supplies signals at 100 sec. intervals. The ten output lines 36 of dividing circuit 34 are connected, respectively, to the ten positions of a switch 50 and, similarly, the lines are connected to switches 52, 54, 56. In the same way, lines 40 of dividing circuit 38 are connected to switches 58, 60, 62, 64 and lines 44 of dividing circuit 42 are connected to switches 66, 68, 70, 72. The four switch groups are connected, respectively, to AND gates 74, 76, 78, 80. A fifth switch group 51, 53, 55 and AND gate 57 provides a pulse on line 59 to reset the dividing circuits 34, 38, 42. The output of AND gate 74 initiates A phase green; similarly, gate 76 initiates A phase yellow, gate 78 B phase green and gate 80 B phase yellow. Thus, by setting the switches 50 ... 72 at appropriate positions the duration of the red, yellow and green periods of the phases A, B are selected as desired. The outputs of the AND gates are supplied to an encoder 90 and to a memory 89, the encoder being utilized when there is a long transmission path to the traffic lights 20 since it enables the number of wires to be reduced; if the path is short the memory 89 is used. The memory outputs 91, 93, 95, 97 are connected directly to a function steering logic 170 whereas the encoder outputs 92, 94, 96, 98 are connected to a decoder 160 having outputs 162, 164, 166, 168 connected to the logic 170. The logic outputs operate the lights 20 through switches 172, 174, 176, 178, 180, 182 each of which includes a relay and triac. The encoder circuit 90 is described with reference to Fig. 4 (not shown) and the decoder 160 and logic 170 with reference to Fig. 6 (not shown).