Abstract: An example electric motor including a conductive winding, a switching device, a rotor, and a controller is disclosed. The switching device is configured to selectively energize, by an AC source, a first portion of the conductive winding in a first state and a second portion of the conductive winding in a second state. The conductive winding generates a magnetic field having a first strength in the first state and a second strength in the second state. The rotor magnetically interacts with the magnetic field such that a torque is applied to the rotor. The amount of torque applied is related to the strength of the magnetic field. The controller is configured to: (i) determine a metric indicative of a load condition of the electric motor; and (ii) based on the determined metric, cause the switching device to switch between the first state and the second state one or more times.

Abstract: An electric motor including a first conductive winding, a second conductive winding, a rotor, and a controller is disclosed. When energized by an AC source, the first conductive winding generates a first magnetic field. The second conductive winding, which is configured to be selectively energized by the AC source via one or more switches, is arranged so as to generate a second magnetic field superimposed with the first magnetic field when so energized. The rotor magnetically interacts with the first magnetic field, or the superimposed first magnetic field and second magnetic field, such that a torque is applied on the rotor. The controller is configured to: (i) obtain a measurement of a voltage of the AC source; (ii) make a determination, based on the measurement, whether to energize the second conductive winding; and (iii) energize the second conductive winding in accordance with the determination.

Abstract: An electric motor including a first conductive winding, a second conductive winding, a rotor, and a controller is disclosed. When energized by an AC source, the first conductive winding generates a first magnetic field. The second conductive winding, which is configured to be selectively energized by the AC source via one or more switches, is arranged so as to generate a second magnetic field superimposed with the first magnetic field when so energized. The rotor magnetically interacts with the first magnetic field, or the superimposed first magnetic field and second magnetic field, such that a torque is applied on the rotor. The controller is configured to: (i) obtain a measurement of a voltage of the AC source; (ii) make a determination, based on the measurement, whether to energize the second conductive winding; and (iii) energize the second conductive winding in accordance with the determination.

Abstract: A system and method for regulating the root mean square (RMS) voltage delivered to a load by an alternating current (AC) electrical circuit having a line voltage. To avoid radio frequency interference (RFI), the load is disconnected from the AC electrical circuit when energy stored in the load is at or near zero and is reconnected when the line voltage is at or near zero. Inductive loads are disconnected when the line current is at or near zero while capacitive loads are disconnected when the line voltage is at or near zero. The duration of the disconnection does not exceed one half-cycle of the fundamental frequency. Disconnections alternate between removing positive voltage half-cycles and negative voltage half-cycles to avoid a direct current (DC) bias. A system incorporating digital logic elements is provided for implementing the method and for detecting whether the load is inductive or capacitive.

Abstract: A system and method for regulating the root mean square (RMS) voltage delivered to a load by an alternating current (AC) electrical circuit having a line voltage. To avoid radio frequency interference (RFI), the load is disconnected from the AC electrical circuit when energy stored in the load is at or near zero and is reconnected when the line voltage is at or near zero. Inductive loads are disconnected when the line current is at or near zero while capacitive loads are disconnected when the line voltage is at or near zero. The duration of the disconnection does not exceed one half-cycle of the fundamental frequency. Disconnections alternate between removing positive voltage half-cycles and negative voltage half-cycles to avoid a direct current (DC) bias. A system incorporating digital logic elements is provided for implementing the method and for detecting whether the load is inductive or capacitive.