GB1027607A - Arrangements for controlling angular displacement - Google Patents

Abstract

1,027,607. Control of A.C. motors. ASSOCIATED ELECTRICAL INDUSTRIES Ltd. Nov. 12, 1964 [Nov. 18, 1963], No. 45438/63. Heading H2J. [Also in Division G1] .. The displacement of a motor FM is measured by integrating the output of a tachogenerator TG coupled to the motor. As shown for controlling the feed motor of a planing machine, cutting is initiated by push-button switch " ON," which energizes the supply contactor FD through switching devices FPR, which cut-off after a preset number of feeds, AR1 which is opened at the end of a forward stroke and recloses at the end of the return stroke, and FCS which energizes an amplifier FCA feeding contactor FD during the cutting stroke. When the displacement as measured is equal to that preset on a potentiometer PS, a signal from circuit VD is applied to AR1 to switch off the contactor FD and disconnect motor FM from the supply. Simultaneously, a brake switch device BM energizes braking contactor B through amplifier BA to connect the motor stator via a delta connection of capacitors CD to a D.C. braking supply. Contactor B is restored to normal after a period determined by timing device BMT. A further timing device FRT produces a signal similar to that from circuit VD if the latter fails to do so in a given time.