GB1239603A - - Google Patents

Abstract

1,239,603. Selective signalling. NATIONAL RESEARCH DEVELOPMENT CORP. 24 Oct., 1969 [24 July, 1968], No. 35347/68. Heading G4H. [Also in Division H3] In a system for processing a pulse train, for example for measuring the average speed of a vehicle over a predetermined distance, the pulse train is notionally divided into groups of n 1 .n 2 ; pulses by counters 21, 23, Fig. 2, and during each group of n 1 .n 2 pulses a gate 14 is opened for a preset period by a monostable 22 once every n 1 pulses, so that in every group of n 1 .n 2 pulses n 3 sub-groups of pulses pass through gate 14, each sub-group containing a number of pulses depending upon the repetition frequency of the pulses. Pulses from gate 14 pass through one of two gates 15, 16, which are opened alternately every group of n 1 .n 2 pulses by a bi-stable 24, to pass to a corresponding counter 17, 19, the contents of each being printed 25 whilst the other is counting. As applied to measuring the average speed of a vehicle over a predetermined distance, each pulse represents an equal increment of travel of the vehicle, and the sub-groups of pulses, which approximate to measures of instantaneous speeds of the vehicle, are uniformly distributed with respect to distance. The system is also said to be of use in measuring the sideway force co-efficient for a vehicle.