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    Dynamoelectric machine control circuit having current limiting means
    1.
    发明授权
    Dynamoelectric machine control circuit having current limiting means 失效
    具有电流限制装置的电动机控制电路

    公开(公告)号：US3683252A

    公开(公告)日：1972-08-08

    申请号：US3683252D

    申请日：1970-05-20

    Applicant: SMITH CORP A O

    Inventor： MAYNARD JOHN T

    IPC: H02P7/292 ,  H02P5/16

    CPC classification number: H02P7/293 ,  Y10S388/902 ,  Y10S388/903 ,  Y10S388/917

    Abstract: A D.C. shunt motor armature is connected to a three-phase A.C. input through a pair of parallel-connected, full-wave, silicon controlled bridge rectifiers to selectively vary the voltage and current supply to the armature. The controlled rectifiers are phase controlled in accordance with a command voltage, an armature voltage and a modifying voltage proportional to the counterelectromotive force for IR compensation and armature current for current limit. The modifying voltage includes an armature current related signal establishing a percentage armature current compensation which is of the order of 50 percent and greatly in excess of the normal IR compensation and directly establishes a continuous current limit to positively prevent excessive armature current by phasing back of the bridge rectifiers.

    Abstract translation: 直流分流电机电枢通过一对并联连接的全波硅控桥式整流器连接到三相交流输入端，以选择性地改变向电枢供电的电压和电流。 受控整流器根据指令电压，电枢电压和与用于IR补偿的反电动势成比例的电流电流和电流限制的电枢电流进行相位控制。 修正电压包括电枢电流相关信号，建立百分之五十的百分比电枢电流补偿，大大超过正常的IR补偿，并直接建立一个连续电流限制，以通过相位回归来正确地防止过大的电枢电流 桥式整流器。

    Condition responsive motor control having unijunction firing circuit for a triggeredswitch
    4.
    发明授权
    Condition responsive motor control having unijunction firing circuit for a triggeredswitch 失效
    条件响应电机控制具有用于触发开关的单点触发电路

    公开(公告)号：US3403314A

    公开(公告)日：1968-09-24

    申请号：US50096665

    申请日：1965-10-22

    Applicant: SMITH CORP A O

    Inventor： MAYNARD JOHN T

    IPC: G05D23/24

    CPC classification number: G05D23/24 ,  G05D23/1906

    Abstract: 1,169,015. Control of A.C. motors. A. O. SMITH CORP. 21 Oct., 1966 [22 Oct., 1965], No. 47345/66. Heading H2J. [Also in Division G3] An A.C. motor is energized via a triggered switch (semi-conductor device 8) which conducts in either direction when triggered at 11, the triggering circuit comprising a unijunction transistor 14 in series with a pulse transformer 13 across a rectifying bridge 26-29, the phase angle of the triggering pulse being dependent on the time constant of a capacitor 36 circuit which includes a condition responsive device, e.g. a thermistor 18. The thermistor detects the temperature of a refrigerator condenser 2 and the system controls the speed of a split phase induction motor 7 driving a cooling fan 6. The unijunction transistor is made insensitive to ambient temperature by a potential divider 32, 33. Resistor 24 and capacitor 25 absorb the back e.m.f. The circuit elements may be mounted as integral with the end frame of the motor.

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