GB840539A - Improvements in or relating to electrical pulse-counting devices - Google Patents

Abstract

840,539. Electronic counting - apparatus. ERICSSON TELEPHONES Ltd. Feb. 20, 1959 [March 18, 1958], No. 8710/58. Class 106 (1). An electrical pulse counter is adapted to count, additively and subtractively, pulses in each time-position of a multiplex system. A binary counter is described for pulses having a duration t occurring at intervals T, T being the time of a multiplex cycle. Each counter stage comprises a delay device such as D1, having a delay time of T. Pulses to be added arrive at a terminal I1 and pass via a gate G1 which is open unless a pulse to be subtracted arrives simultaneously on a lead I2, to the control gate G3 of the first counter stage. Assuming the counter initially to register zero, the first pulse to be added in a particular time of the multiplex cycle passes via gates G3, G1 to be stored in a delay device D1, an output appearing periodically at the appropriate differential time at P1. The gate G3 is now inhibited and a gate G4 opened so that the next pulse to be added is stored in the next denominational delay device D2, the pulse in the first device D1 being pecked out by an inhibitory gate G8. Assuming the counter to register eight, i.e. a pulse to be circulating the delay device D3 only, a pulse to be subtracted on the lead I2 is effective, if it is not coincident with an additive pulse, to cause via gates G25, G28 the pulse circulating in the device D3 to be pecked out and via gates G25 and G17, G7 respectively a pulse to be inserted in the two lower orders. The counter thus registers the difference in number of additive and subtractive pulses, but only when the number of additive pulses is the greater, the outputs appearing successively at the terminals P1-P4 representing the counts in the various time positions of the multiplex cycle.