Patent GB-876378-A (GB)
Title: Improvements in or relating to time regulated automatic control systems
Inventor: PARTINGTON GEORGE EARNSHAW
IPC: G04C23/08
Filed: 1958-10-13
Abstract: 876,378. Time control of electric circuits. MARCONI'S WIRELESS TELEGRAPH CO. Ltd. June 15, 1959 [Oct. 13, 1958], No. 32589/58. Class 118. A time-regulated automatic control system applicable to television switching systems includes a record on which is recorded in coded form both control function information and the time information at which the predetermined desired control functions are to be performed. A tape reader TR is provided for reading off the recorded time and control function, the tape normally being stationary with respect to the tape-reader and an independent time control device SC is adapted to translate times occurring at regular predetermined intervals each into a different setting of a time-controlled mechanism. A relay RL is connected to a coincidence detector CD, responsive to correspondence between a time already being read off by the tape reader from the record and a time setting of the time-controlled mechanism for initiating performance of the recorded control functions to be performed at that time by means of the selector magnet SM connected to the wiper of selector G1. The relay also operates the magnet TM for causing relative movement between the record and reader to bring the latter in position to read off the next recorded time at which the recorded control functions are to be performed. The independent time control consists of six banks of uniselector switches A, B, C, D. E, F, Fig. 1, each bank having a number of switches, the banks corresponding to tens of hours, units of hours, tens of minutes, units of minutes, tens of seconds and units of seconds. A potential source is connected to terminal H and thence to the bank of switches in accordance with an International code on the tape. To the uniselector switches is connected a bank G of column selectors having the fixed ends of the individual switch wipers connected to the corresponding input terminals of the coincidence detector. The tape in the tape reader is coded in such a way that the first column to enter the tape reader is that corresponding to tens of hours and so on to units of seconds, this then being followed by the first character of the control information to be passed at the time indicated. When the clock reaches the time represented by the tape characters, corresponding potentials will be applied to the column selectors and thence to the coincidence detector, thus causing the relay RL to be released and hence the tape in the tape reader to move on one column and the column selector 61 to move to position 2. After the column selector has been in position 6, representing coincidence in seconds, it proceeds to connect at position 10, missing out positions 7, 8, 9, to the decoder DC, so that the decoder then hunts until its output is in coincidence with that of the tape reader. When this occurs the column selector G1 moves to position 11 and the tape moves to the second character of the control information. The decoder DC is so adapted that when coincidence occurs on the second code character an output signal is applied to the desired circuit to carry out the desired control operation. When all the control information has been decoded the selector G1 is caused to return to position 1. Where the start of a sequence of operations cannot be accurately determined beforehand the use of a special code may be timed to cause the selector G1 to move to position 7 before the sequence of operations is required, terminals 7, 8, 9 being connected to a manually initiated cue clock CC similar to the time control device SC but covering only the ten minutes during which the control operation is to take place. In an alternative arrangement the tape moves automatically after the elapse of a predetermined time after the occurrence of coincidence between a time read off from the tape and a setting of the time-controlled mechanism. Although as described a single decoder has been used to operate sequentially, separate decoders, one for each of the number of control function code entries for each time entry may be used. In addition a multi-column tape reader may be used thus allowing for the simultaneous decoding of a number of column entries. In another arrangement the part of the coded record carrying control function information is arranged to enter the tape reader prior to the corresponding coded time information and the control function information is stored so that the occurrence of time coincidence between the coded time information and the standard clock is utilized to initiate performance of the control function to which the stored information corresponds. Specification 865,242 is referred to.