GB1252528A - - Google Patents

Abstract

1,252,528. Statistical apparatus; selective signalling. SVENSKA DATAREGISTER A.B. 23 April, 1969 [9 May, 1968], No. 20812/69. Headings G4H and G4M. Information represented by the spacing of adjacent pulses in a train is detected by a system comprising a first storage unit and one or more second storage units corresponding in number to the number of possible intervals between pulses, a value corresponding to the spacing of a pulse pair being transferred from the first unit to the second units which are then allowed to charge their stored value linearly over the following interval between pulses so that for an interval other than the shortest possible interval, one of the second units reaches a reference level. In one embodiment. Fig. 1, pulses B, C, D are derived sequentially from each input pulse so that for each pulse, bi-stable 32 is reset if it is not receiving an input from comparator 28, the voltage on first capacitor 16 is transferred to second capacitors 22 via switches 20, and capacitor 16 is discharged via switch 14. In the interval before arrival of the next pulse, capacitor 16 charges linearly from constant current source 18 and capacitors 22 discharge linearly through the associated constant current transistor 26. If a capacitor 22 fully discharges before the next pulse arrives, the associated bi-stable 32 is set to identify the occurrence of the corresponding interval between pulses, and the current drawn by the transistor 26 in the next pulse interval is modified so that, although a higher voltage is transferred from capacitor 16, the time to discharge to the reference level is the same as for the voltage corresponding to the shortest possible interval. A functionally similar arrangement using counters advanced by clock pulses instead of capacitors is also described, Fig. 4 (not shown).