MOTOR CONTROLLER AND RELATED METHOD
First Claim
1. A motor controller which modifies an input current to an alternating current (AC) motor, where said motor has at least one winding, the motor controlling comprising:
- a power input rectifier;
a low voltage power supply to supply power to a control circuit;
a variable output voltage circuit for providing a variable DC voltage to the drive output voltage circuit to provide power to the at least one winding; and
a control circuit arranged to control the variable output voltage circuit and to provide timed waveforms to the drive output voltage circuit.
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Abstract
The present invention relates to a motor controller and related method. The invention is particularly well suited for use with an alternating current (AC) induction motor. Previously motor controllers did not take into account the combined effect a control circuit and controlled motor, had upon a mains supply and more particularly their separate and combined effect upon the power factor of an alternating current. The invention solves this problem by providing a motor controller which modifies an input current to an alternating current (AC) motor. The motor controller comprises: a power input rectifier; a low voltage power supply; a variable output voltage circuit for adjusting a drive output voltage circuit; and a control circuit arranged to control the variable output voltage circuit and to provide timed waveforms to the drive output voltage circuit.
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Citations
34 Claims
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1. A motor controller which modifies an input current to an alternating current (AC) motor, where said motor has at least one winding, the motor controlling comprising:
- a power input rectifier;
a low voltage power supply to supply power to a control circuit;
a variable output voltage circuit for providing a variable DC voltage to the drive output voltage circuit to provide power to the at least one winding; and
a control circuit arranged to control the variable output voltage circuit and to provide timed waveforms to the drive output voltage circuit. - View Dependent Claims (2, 3, 4, 5, 6, 11, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 28)
- a power input rectifier;
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7. A motor controller which modifies an input current to an alternating current (AC) motor, said motor has at least one winding, the motor controller comprising:
- a power input rectifier, a low voltage power supply to supply voltage to a control circuit;
a variable output voltage circuit for adjusting maximum (or minimum) value of the drive output voltage supplied to the at least one winding;
a drive output voltage circuit to drive the motor and a control circuit arranged to control the variable output voltage circuit, and means to control the drive output voltage circuit so as to provide time varying waveforms to the output circuit. - View Dependent Claims (10)
- a power input rectifier, a low voltage power supply to supply voltage to a control circuit;
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8. A motor controller which modifies an input current to an alternating current (AC) motor, said motor has at least one winding, the motor in use adapted to be connected, in series, with said first input current and to derive a modified drive current waveform therefrom, the controller comprising:
- a low voltage power supply;
a rectification circuit;
a variable voltage and power factor correction circuit;
a multiphase output circuit;
a control circuit arranged to control the variable voltage and power factor correction circuit and the multiphase output circuit being arranged so as to provide a modified drive output voltage which is variable. - View Dependent Claims (9, 12, 13, 14)
- a low voltage power supply;
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27. A method of controlling a motor comprising the steps of:
- varying an input voltage and/or current;
selecting an instantaneous voltage according to the requirements of the motor and applying said instantaneous voltage to a desired winding of the motor.
- varying an input voltage and/or current;
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29. A motor controller which modifies an input current to an alternating current (AC) motor, where said motor has at least one winding, the motor controller comprising:
- a power input rectifier; and
output voltage circuit for providing a drive output; and
a control circuit arranged to control the drive output voltage to provide timed waveforms to the drive output voltage circuit;
the control circuit including a means for modifying an input operable to adjust the time waveforms so that a near unity power factor is presented to a mains supply. - View Dependent Claims (30, 31)
- a power input rectifier; and
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32. A method of controlling a motor comprising the steps of:
- modifying an input current to an alternating current (AC) motor, the motor having first and second windings, the steps comprising;
deriving a low voltage power supply;
rectifying said supply;
providing a reduced DC voltage while presenting an acceptable power factor to the supply, providing control and timing signals and providing a multiphase output stage so as to provide the modified drive voltage and current whose value is zero for a predetermined time duration (T).
- modifying an input current to an alternating current (AC) motor, the motor having first and second windings, the steps comprising;
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33. A motor controller substantially as herein described and with reference to the drawings.
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34. A method of controlling a motor substantially as herein described.
Specification