GB1489363A - Electric signal pulse sampler - Google Patents

Abstract

1489363 Data transmission; signalling by DC PLESSEY CO Ltd 23 June 1975 [22 Oct 1974] 45633/74 Heading H4P A pulse signal sampling circuit for a succession of pulses in a determined slot of a repetitive cycle where each pulse may have distorted leading and trailing edges with a central undistorted part, has sampling instants varied in time relative to the theoretical centre of the undistorted portion of the signal pulses; relevant portions of these pass through a gate which is opened at the sampling instants. Variation of the sampling instants about the centre may be in cyclic manner, and the time interval between successive instants may be greatest at the centre and decreasing towards extremities. Separate arrangements are described in the Specification to produce such cyclic variation. In Fig. 3 (not shown) a modulation frequency is applied to a terminal (M) connected to the junction of opposed varactor diodes (15, 16) connected across a capacitor loaded transformer primary winding (11), the secondary (12) being connected to the enabling terminal of a gate (G, not shown). In Fig. 4 (not shown) a variable delay (21) co-operates with a monostable device (22) the delay being regulated by a modulation potential applied to terminal (M). In a third arrangement (Fig. 5, not shown) a phase locked loop has its operating frequency varied by the modulating potential (M) applied to the input or output of a filter (32). In the embodiments described eight sampling pulses comprise one cycle of time modulation. The modulator cycle time should not cause interference with the repetition frequency of signal pulses.