Control circuits for motors and related methods
AssigneeEmerson Electric Co.
InventorsJohn F. Broker, Roger R. Maus
Life of this patent
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Abstract
Control circuits and related methods are provided. One exemplary control circuit includes a solid state switching device for coupling to a first tap of a motor and a control device coupled to the solid state switching device. The control device is configured to switch the solid state switching device to apply a signal to the first tap in response to a demand for operation of the motor at a second parameter to operate the motor at the second parameter. The control device is also configured to switch the solid state switching device to apply a signal to the first tap in response to a demand for operation of the motor at a first parameter to operate the motor at the first parameter.
Claims19
A control circuit for a motor of a HVAC system, the motor including at least a first tap and a second tap, the motor configured to operate at a first parameter when the first tap is energized and at a second different parameter when the second tap is energized, the control circuit comprising:
- a solid state switching device for coupling to the first tap of the motor;
- and
- a control device coupled to the solid state switching device, the control device configured to switch the solid state switching device to apply a first control signal to the first tap, in response to a demand for operation of the motor at the second parameter, to operate the motor at the second parameter, the control device configured to switch the solid state switching device to apply a second control signal to the first tap, in response to a demand for operation of the motor at the first parameter, to operate the motor at the first parameter;
- wherein the solid state switching device is a bipolar junction transistor having a base, an emitter and a collector, wherein the base is coupled to the control device, and wherein the collector is coupled to a power supply;
- and
- wherein the control circuit further comprises:
- an output for coupling to the first tap of the motor, wherein the collector of the transistor is coupled to the output;
- and
- a diode coupled in series between the collector of the transistor and the output, the diode configured to substantially prevent current flow from the output to the collector.
A method of controlling a motor including at least a first tap and a second tap, the motor configured to operate at a first parameter when the first tap is energized and at a second different parameter when the second tap is energized, the method comprising:
- applying, by a solid state switching device, a first control signal to the first tap to operate the motor according to the first parameter, when a demand indicates operation of the motor at the first parameter;
- and
- applying, by the solid state switching device, a second control signal to the first tap to operate the motor according to the second parameter, when the demand indicates operation of the motor at the second parameter;
- wherein the first control signal is a direct current (DC) control signal, and wherein the second control signal is a DC control signal;
- wherein the motor further includes a third tap and a fourth tap, the motor configured to operate at a third parameter when the third tap is energized and a fourth parameter when the fourth tap is energized, and the solid state switching device is a first solid state switching device;
- and
- wherein the method further comprises:
- applying, by a second solid state switching device, the first control signal to the third tap to operate the motor according to the third parameter, when the demand indicates operation of the motor at the third parameter;
- and
- applying, by the second solid state switching device, the second control signal to the fourth tap to operate the motor according to the fourth parameter, when the demand indicates operation of the motor at the fourth parameter.
A motor control assembly comprising:
- a motor including:
- a motor controller,
- a first input circuit coupled to the motor controller, the first input circuit including a first tap, a second tap, a first opto-isolator, and a first diode, the first opto-isolator coupled to the motor controller, the first tap, and the second tap, the first diode coupled in series between the first tap and the first opto-isolator, the first input circuit configured to apply a first control signal to the motor controller in response to an AC signal at the first tap to operate the motor at a first parameter, and
- wherein the first input circuit is configured to apply a second control signal to the motor controller, in response to an AC signal at the second tap to operate the motor at a second parameter;
- the first control signal defining a first signal pattern, the second control signal defining a second signal pattern;
- and
- a control circuit coupled to the motor and configured to apply a first direct current (DC) control signal to the first tap, the first DC control signal substantially consistent with the first signal pattern, when a demand indicates a request for operation of the motor according to the first parameter, and the first DC control signal substantially consistent with the second signal pattern, when the demand indicates a request for operation of the motor according to the second parameter.
Dependencies are inferred from the claim text.