Electronically controlled switch for an electric motor

A method of controlling an electric motor system, the electric motor system including an electric motor having a run winding and a start winding and a motor control subsystem, the motor control subsystem including a control unit, first and second electronically controlled switches, and a sensor, the method comprising the steps of:

• (1) sending by the control unit a first control signal to close the first electronically controlled switch and thereby energize the run winding of the electric motor;
• (2) sending by the control unit a second control signal to close the second electronically controlled switch and thereby energize the start winding of the electric motor;
• (3) receiving at the control unit an input signal from the sensor regarding a voltage or a current to the electric motor;
• (4) determining by the control unit based on the input signals whether the electric motor has started;
• and
• (5) if the electric motor has started, sending by the control unit a third control signal to open the second electronically controlled switch and thereby de-energize the start winding of the electric motor.

A motor control subsystem for an electric motor system including an electric motor having a run winding and a start winding and further including a user interface configured to receive a user input from a user, the motor control subsystem being configured to control operation of the electric motor and an operationally associated additional component which are both part of a machine, the motor control subsystem comprising:

• a control unit in electrical communication with the user interface and configured to receive the user input from the user interface;
• a first electronically controlled switch electrically connected in series between the control unit and the run winding of the electric motor and configured to control a flow of electric current to the run winding in response to a first control signal from the control unit;
• a second electronically controlled switch electrically connected in series between the control unit and the start winding of the electric motor and configured to control the flow of electric current to the start winding in response to a second control signal from the control unit;
• and
• a sensor in electrical communication with the control unit and configured to sense a voltage or a current to the electric motor and to provide an input signal to the control unit regarding the sensed voltage or current,
• wherein the control unit
• sends a first control signal to close the first electronically controlled switch and thereby energize the run winding of the electric motor,
• sends a second control signal to close the second electronically controlled switch and thereby energize the start winding of the electric motor,
• determines based on the input signal whether the electric motor has started, and
• if the electric motor has started, sends a third control signal to open the second electronically controlled switch and thereby de-energize the start winding of the electric motor, and activates the operationally associated additional component.