Switch assembly, electric machine having the switch assembly, and method of controlling the same

An electric machine connectable to a power supply, the electric machine comprising:

• a rotor;
• a main winding;
• and
• an auxiliary circuit in a non-series relationship with the main winding, the auxiliary circuit comprising an auxiliary circuit element and an electronic switch assembly electrically connected in a series relationship such that the electronic switch assembly controls current through the auxiliary circuit element, the electronic switch assembly comprising
• an electronic switch;
• a controller connected to the electronic switch to control the electronic switch;
• a power supply connectable to the power source and connected to the controller, the power supply being configured to receive power from the power source and controllably power the controller, the power supply including a circuit clamp connectable to the power source and connected to the controller, the circuit clamp obstructing power from powering the controller when the voltage of the received power is greater than a threshold, thereby preventing current through the auxiliary circuit component.

A method of controlling an electric machine with power from a power source, the electric machine comprising a rotor, a main winding circuit comprising a main winding, and an auxiliary circuit connected in a parallel relationship with the main winding circuit, the auxiliary circuit comprising an auxiliary circuit element and an electronic switch assembly electrically connected in a series relationship such that the electronic switch assembly controls current through the auxiliary circuit element, the electronic switch assembly including an electronic switch, a controller connected to the electronic switch to control the electronic switch, and a power supply connected to the power source and the controller, the method comprising the acts of:

• connecting the electronic switch assembly to the power source;
• powering the power supply;
• determining at the power supply whether the voltage of the power is greater than a value;
• obstructing the power from powering the controller when the voltage is greater than the value, and
• preventing current through the auxiliary circuit component in response to the obstructing act.

A method of controlling an electric machine with power from a power source, the electric machine comprising a rotor, a main winding, and an auxiliary circuit connected in a non-series relationship with the main winding, the auxiliary circuit comprising an auxiliary circuit element and a switch assembly electrically connected in a series relationship such that the switch assembly controls the current through the auxiliary circuit element, the switch assembly including a switch and a controller connect to the electronic switch to control the electronic switch, the method comprising the acts of:

• connecting the motor to the power source;
• allowing current through the electronic switch;
• monitoring the current;
• and
• preventing current through the electronic switch when the monitored current flares.

An electric machine connectable to a power supply, the electric machine comprising:

• a rotor;
• a main winding circuit comprising a main winding, and
• an auxiliary winding circuit connected in a parallel relationship with the main winding circuit, the auxiliary winding circuit comprising an auxiliary circuit element and a switch assembly connected in a series relationship such that the switch assembly controls the current through the auxiliary circuit element, the switch assembly comprising
• a switch,
• a controller connected to the switch to control the switch, the controller comprising a current sensor that senses a current through the switch, a scalar that generates a threshold based on the sensed current, and decision logic that controls the switch based on the sensed current and the threshold;
• wherein the scalar generates a threshold having a relation to the sensed current such that the decision logic detects when the sensed current flares.

An electric machine connectable to a power supply, the electric machine comprising:

• a rotor;
• a main winding;
• and
• an auxiliary circuit connected in a non-series relationship with the main winding, the auxiliary circuit comprising an auxiliary circuit component and an electronic switch assembly electrically connected in a series relationship such that the electronic switch assembly controls the current through the auxiliary circuit element, the electronic switch assembly comprising
• an electronic switch,
• a generator that provides a first signal,
• a circuit control including a current sensor that senses a current through the electronic switch, the circuit control providing a second signal based on the sensed current,
• decision logic connected to the generator, the circuit control and the electronic switch, the decision logic receiving the first and second signals and generating a control signal that selectively controls the electronic switch based on the first and second signals.