GB1358393A - Multi-channel pulse combining system - Google Patents

Abstract

1358393 Summing pulses DECCA Ltd 26 May 1972 [28 May 1971] 17956/71 Heading G4D A system for combining pulse trains from several input channels 6a, 6b, 6c into a single output 9, e.g. feeding a counter 10, without loss of coincident pulses, comprises a plurality of clocked bi-stable switching circuits 8a, 8b, 8c which respectively receive the inputs from 6a, 6b, 6c and which are such as to be set when a clocking pulse coincides with an input pulse and to be reset by a clocking pulse in the absence of an input pulse; a generator 1-5 for feeding clock pulses in succession to the bi-stables 8a, 8b, 8c; and means 7a, 7b, 7c for extending each input pulse to be at least as long as the period between consecutive clock pulses applied to the respective bi-stable. The bi-stables 8a, 8b, 8c may be D-type flip-flops. The clock generator comprises an oscillator 1, a BCD counter 2 and a decoder 3 connected to apply pulses successively to open gates 5a, 5b, 5c to release oscillator pulses in succession to the bi-stables. The arrangement is such that the bi-stables, when receiving coincident pulses, are set in succession by the receipt of clocking pulses. The setting of the bi-stables is registered by the counter 10. As above described each extended input pulse will overlap two clock pulses, a third is required to reset it and a new output cannot be generated until the fourth consecutive clock pulse applied to that bi-stable. To increase the maximum counting speed a circuit including a gate 11 is added to each bi-stable 8 and is effective to reset the bi-stable by the next oscillator pulse following the end of the extended input pulse. The inputs 6a, 6b, 6c may be from detectors responding to objects moving along a plurality of parallel paths.