Abstract: A pressure probe assembly for attachment to a venturi of a gas-fired appliance, where the venturi includes a body having an inlet end, an outlet end, and a wall defining a mixing chamber extending from the inlet end to the outlet end about an axis. A support member is detachably coupled to the mixing chamber. A first pressure probe is coupled to the support member and has a first pressure tap disposed substantially adjacent the axis. A second pressure probe is coupled to the support member and has a second pressure tap disposed substantially adjacent the mixing chamber wall. Also disclosed is a gas-fired appliance, such as a water heater, including the pressure probe assembly.

Abstract: A pump system. The pump system includes a pump, a motor coupled to the pump, a sensor coupled to a power source, and a controller. The motor operates the pump. The sensor detects an electrical characteristic of the power source. The controller executes a fault check, controls the motor, detects a change in the electrical characteristic, and suspends the execution of the fault check for a predetermined period of time when the detected change in the electrical characteristic is outside of a valid characteristic range.

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: A system for determining a temperature of a medium, such as water, in a volume, such as a water heater tank. The system includes a temperature sensor array and a variable frequency voltage supply. A first temperature sensing unit of the temperature sensor array includes a temperature sensor in parallel with a capacitor. The capacitor is selected such that the impedance is low relative to the resistance of the temperature sensor at frequencies above a threshold and high at frequencies below a threshold. A second temperature sensing unit of the array includes a second temperature sensor. The temperatures sensed by the various temperature sensors in the array are determined by selectively varying the frequency of the voltage supply.

Abstract: A pumping apparatus for a jetted-fluid system includes a pump having an inlet connectable to the drain, and an outlet connectable to the return. The pump is adapted to receive the fluid from the drain and jet fluid through the return. The pumping apparatus includes a motor coupled to the pump to operate the pump, a sensor connectable to the power source and configured to generate a signal having a relation to a parameter of the motor, and a switch coupled to the motor and configured to control at least a characteristic of the motor. The pumping apparatus also includes a microcontroller coupled to the sensor and the switch. The microcontroller is configured to generate a derivative value based on the signal, and to control the motor based on the derivative value.

Abstract: A flame rod analysis system, methods for determining a condition of a flame and a flame rod, and circuits for determining a condition of a flame and a flame rod. The flame rod analysis system comprises energy storage connectable to a flame rod, a pulsed source connected to the energy storage and providing a voltage pulse or a current pulse, and a buffer to allow a processor to measure a buffered voltage at various time points. Flame rod analysis systems can distinguish between various flame conditions (no flame, low flame, etc.) while simultaneously characterizing the condition of the flame rod (shorted to ground, contaminated, etc.). Some flame rod analysis systems can directly measure the resistance of the flame rod.

Abstract: A pump system. The pump system includes a pump, a motor coupled to the pump, a sensor coupled to a power source, and a controller. The motor operates the pump. The sensor detects an electrical characteristic of the power source. The controller executes a fault check, controls the motor, detects a change in the electrical characteristic, and suspends the execution of the fault check for a predetermined period of time when the detected change in the electrical characteristic is outside of a valid characteristic range.

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 apparatus and method of maximizing the efficiency of an induction motor is claimed. Three phase AC power is supplied to energize the motor. A DC voltage and a DC current are measured and used to determine an estimated phase voltage. An actual torque producing current is determined based on the DC voltage, DC current and the estimated phase voltage. An estimating torque producing current value is determined and compared with the actual torque producing current value. An error term representing the difference between the actual and estimated torque producing current values is determined. The estimated phase voltage value is changed based on the error term. The three phase AC power supplied to the motor is adjusted based on the estimated phase voltage.

Abstract: An apparatus and method of determine rotor position for a switched reluctance motor is claimed. A phase voltage and a phase current are measured. An estimated flux voltage value is determined from the measured phase voltage and the phase current. The phase current is again measured when the estimated flux linkage value is approximately equal to a reference flux linkage value. Rotor position is determined based on the reference flux linkage value and the measured phase current value.

Abstract: A method and apparatus for improving the efficiency of an induction motor used in fluid pump and blower applications including a controller that reduces the flux generated by the motor at less than maximum motor loads.

Abstract: A motor controller for brushless motors operates an inverter in a current-controlled mode for low motor speeds and in a voltage-controlled mode for high motor speeds. By switching from the current-controlled mode to the voltage-controlled mode at higher speeds, the motor can be designed at maximum efficiency, and minimum weight, cost and volume.