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专利名称：Voltage controlled, variable time delay
electronic interval timer for motor control
发明人：James E. Hansen申请号：US06/540738申请日：19831011公开号：US04490659A公开日：19841225
摘要：A pair of interval timer units including a lower right timer (LRT) and a lower lefttimer (LLT) for controlling a pair of D.C. motors (RM, LM) to drive a pair of load devicesaccurately and consistently a predetermined lowering distance. The load devices areraised together until stopped by limit switches (LS1, LS2) but can be lowered individuallyunder the interval timer (IT) control. Each timer unit (LRT) includes a voltage regulator(ZD1, ZR1) to provide a constant voltage to a ramp voltage generator (RG) and a
reference voltage to a voltage inverter (VI). The ramp voltage is applied through a buffer(IC1B) to one input of a comparator (IC1C). The variable supply voltage is also applied tothe voltage inverter (VI) that provides a time reference voltage that varies inversely withrespect to variation in the supply voltage. This time reference voltage is applied to thecomparator (IC1C) upon closure of a \"lower\" switch to close a motor control switch (Q3)to start the motor time interval and when the ramp voltage rises to the level of the timereference voltage, the comparator (IC1C) opens the motor control switch (Q3) to stopthe motor time interval. As a result, since the motor speed changes with change in supplyvoltage, the interval timer varies inversely the motor operating time for constant loaddriving distance.
申请人：EATON CORPORATION
代理人：C. H. Grace,W. A. Autio
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