Abstract: A water heating system includes a compressor unit fluidly coupled to a first heat exchanger and a controller operatively coupled to the compressor unit. The controller is configured to operate the compressor unit in a heating mode to circulate refrigerant between the compressor unit and the first heat exchanger in a first direction, determine a loss of superheat in the first heat exchanger while the compressor unit is operating in the heating mode, and initiate a defrosting sequence in response to determining the loss of superheat in the first heat exchanger.

Abstract: An electronic controller for controlling a heat pump water heater is configured to receive a first signal from a first sensor and receive a second signal from a second sensor. The first signal is indicative of a first variable the second signal is indicative of a second variable. The electronic controller is configured to determine a target flow rate based on the first variable and the second variable and control a water flow rate of the heat pump water heater based on the target flow rate.

Abstract: A water heating system includes a burner and a gas valve fluidly connected to the burner to deliver a flow of combustible gas thereto. The gas valve has an adjustable throttle for the flow of combustible gas, along with a motor to adjust a position of the throttle. A controller is configured to determine a throttle position corresponding to a target air-fuel ratio of the burner during a calibration sequence, and to control the motor in order to operate the burner at that target air-fuel ratio throttle position during a start sequence. The controller is configured to monitor a characteristic of the burner during the start sequence, and to initiate the calibration sequence if the monitored characteristic exceeds an error threshold.

Abstract: A method of manufacturing a core for an electrical machine. The method includes providing a planar sheet of magnetic material and creating first and second generally U-shaped laminations from the planar sheet. The first and second generally U-shaped laminations result from a pattern formed in the planar sheet. The pattern includes the first generally U-shaped lamination having a first leg and a second leg, and the second generally U-shaped lamination rotated one hundred-eighty degrees with respect to the first generally U-shaped lamination. The second generally U-shaped lamination includes a third leg and a fourth leg. The third leg is disposed between the first and second legs. The method further includes creating the core by stacking the first and second generally U-shaped laminations.

Abstract: A method of and apparatus for controlling an electric machine.

Abstract: An electrical machine having a stator and a rotor. The stator includes a core and a plurality of windings disposed on the core in a multiple-phase arrangement. The rotor is disposed adjacent to the stator to interact with the stator. A method of operating the motor includes applying a pulsed voltage differential to first and second terminals of the windings resulting in movement of the rotor; monitoring the back electromotive force (BEMF) of the windings to sense rotor movement; after the applying and monitoring steps, monitoring the BEMF of the windings to determine whether the rotor is rotating in a desired direction, and electrically commutating the motor when the rotor is rotating in the desired direction and zero or more other conditions exist.

Abstract: A method of controlling a motor operating a pumping apparatus of a fluid-pumping application. The pumping apparatus includes a pump having an inlet to receive a fluid and an outlet to exhaust the fluid, and the motor coupled to the pump to operate the pump. The method includes the acts of controlling the motor to operate the pump and monitoring the operation of the pump. The monitoring act includes monitoring a power of the motor, and determining whether the monitored power indicates an undesired flow of fluid through the pump. The method further includes the act of controlling the motor to cease operation of the pump when the determination indicates an undesired flow of fluid through the pump and zero or more other conditions exist.

Abstract: An electric machine having a stator assembly that includes a stator core and a coil supported by the stator core and a rotor assembly that includes a shaft and a rotor supported by the shaft that is in magnetic interaction with the stator core. The electric machine may include a single sensor configured to detect magnetic polarities of the rotor as the rotor rotates relative to the sensor and to generate a signal representing the detected magnetic polarities of the rotor. The signal and an inverted version of the signal are utilized to control current through the coil. The current may be controlled indirectly by controlling the application of voltage to the coil. The sensor may be encapsulated on a circuit board to positively position the sensor relative to the circuit board. The circuit board may be mounted to a bearing housing of the electric machine. The sensor may be received in a pocket of a bearing housing of the electric machine so the sensor is positively positioned relative to the rotor.

Abstract: An electrical machine including a rotor and a stator. The stator includes a core and a coil disposed on the core. In one construction, the core is generally U-shaped and comprises magnetic material. The electrical machine also includes a bridge comprising magnetic material. The bridge connects the first and second legs of the generally U-shaped core. Also disclosed are methods of manufacturing the core.

Abstract: An electrical machine including a rotor and a stator. The stator includes a core and a coil disposed on the core. In one construction, the core is generally U-shaped and comprises magnetic material. The electrical machine also includes a bridge comprising magnetic material. The bridge connects the first and second legs of the generally U-shaped core. Also disclosed are methods of manufacturing the core.

Abstract: A method of and apparatus for controlling an electric machine. The method can include using a controller to detect whether power is present at a first node of the controller, detect whether power is present at a second node of the controller, generate at least one signal based at least in part on the detection, and energize the electric machine using a detected power when the at least one signal indicates power is present at at least one of the first node, the second node, and a combination of the first node and the second node.

Abstract: An electric machine having a stator assembly that includes a stator core and a coil supported by the stator core and a rotor assembly that includes a shaft and a rotor supported by the shaft that is in magnetic interaction with the stator core. The electric machine may include a single sensor configured to detect magnetic polarities of the rotor as the rotor rotates relative to the sensor and to generate a signal representing the detected magnetic polarities of the rotor. The signal and an inverted version of the signal are utilized to control current through the coil. The current may be controlled indirectly by controlling the application of voltage to the coil. The sensor may be encapsulated on a circuit board to positively position the sensor relative to the circuit board. The circuit board may be mounted to a bearing housing of the electric machine. The sensor may be received in a pocket of a bearing housing of the electric machine so the sensor is positively positioned relative to the rotor.

Abstract: A motor control system that switches between voltage control and angle control. The motor control system includes a comparator, an angle control, and a voltage control.

Abstract: An electrical machine including a rotor and a stator. The stator includes a core and a coil disposed on the core. In one construction, the core is generally U-shaped and comprises magnetic material. The electrical machine also includes a bridge comprising magnetic material. The bridge connects the first and second legs of the generally U-shaped core. Also disclosed are methods of manufacturing the core.

Abstract: A controller for an electric machine. The controller includes a first voltage input that directly provides a first voltage to the electric machine, a second voltage input configured to receive a second voltage, and an inverter coupled to the second voltage input. The inverter is configured to be activated by the second voltage, to frequency-regulate the second voltage to generate a frequency-regulated voltage, and to provide the frequency-regulated voltage to the electric machine.