GB1495748A - Mark/space generator - Google Patents

Abstract

1495748 Random pulse generators IWS NOMINEE CO Ltd 10 Nov 1975 [8 Aug 1974] 35071/74 Heading G4D [Also in Division G3] A generator for producing a square wave output with randomly varying mark-space periods, comprises a first counter 38 which continuously counts between limits preset by switches 42-48 from a high speed clock 40; a second counter 30 which counts from a low speed clock 32 and means for detecting the end of a count in counter 30 and reloading counter 30 with the instantaneous value in counter 38, the output signal changing state each time counter 30 reaches its end point. The counter 38 may have separate switches 42, 44 and 46, 48 for setting the limits of the count for the mark and space periods respectively. Each time counter 30 reaches zero a switching device 34 changes state, causing the count in 38 to be loaded in a first store 36 while the count previously stored in the other store 36 is loaded into counter 30; device 34 also selects the appropriate switches 42-48. In a modification (Fig. 3, not shown) the stores 36 are eliminated and counter 38 is stopped while its count is read directly into counter 30. The generator is employed to control a spinning machine producing random slub yards; the output signal controls a relay which switches the speed of certain drive rollers in the spinning machine between a high and low value alternately.