专利名称：Apparatus for controlling an electric motor发明人：Lombardi, Steven A.,Marasch, Richard D.申请号：EP91107054.8申请日：19910501公开号：EP0455237A2公开日：19911106
专利附图：
摘要：A motor controller includes a set of thyristors which couple the motor to asource of alternating electricity. A detector senses when the voltage of the source makesa zero crossing. A mechanism is provided to vary the frequency of a clock signal (GATECLOCK) at a rate determined by a user selectable input which represents the rate at
which the motor speed is to change during starting or stopping. The clock signal (GATECLOCK) is applied to a counter (71) which produces an active trigger signal (FIRE) when agiven number of clock signal cycles have been counted following a zero crossing of thesource voltage. The active trigger signal causes a trigger pulse circuit (72) to apply a brieftrigger pulse to gate electrodes (21, 22, 23) of the thyristors. The varying frequency ofthe clock signal (GATE CLOCK) alters the relative times at which the thyristors aretriggered to vary the amount of voltage applied to the motor. Different frequencyvariation functions can be stored in a memory for the starting and stopping modes.
申请人：ALLEN-BRADLEY COMPANY, INC.
地址：1201 South Second Street Milwaukee Wisconsin 53202 US
国籍：US
代理机构：Lippert, Hans, Dipl.-Ing.
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