Abstract: An apparatus for and method of controlling the circulating fan of a gas appliance. The circulating fan is powered by an alternating current electric motor. An electronic circuit, powered by the heat of the gas appliance, determines the rotational speed of the electric motor by controlling the effective duty cycle of the alternating current source coupled to the electric motor.

Abstract: A drive circuit for a speed adjustable fan comprises a computing IC, a Hall IC, an input terminal for external signals, and a current control circuit. The drive circuit is arranged inside the fan to control the speed of the fan without the need of an external circuit. The computing IC is connected to a Hall IC and controls two transistors connecting therewith in a state of connecting and in a state of disconnecting sequentially such that two coils of the fan are alternately magnetized so as to rotate the fan. The input terminal for external signals detects the current of the external signal source and the current is regulated by the current control circuit in the process of passing through the coils to adjust the speed of the fan.

Abstract: A power steering system and induction motor load compensation algorithm or processing method for use in a vehicle. The power steering system comprises a power supply, a power steering motor, a steering subsystem, and a power steering controller coupled to the power supply. The controller processes a frequency command input corresponding to the power steering frequency requested by the steering subsystem and data contained in one or more software lookup tables to adjust the output frequency produced by the power supply to control the speed of the power steering, motor. The lookup tables are generated empirically and characterize the output power of the power supply at different system pressures over a range of motor speeds. The software lookup tables provide a power band that implements a power limiting state machine.

Abstract: A diagnostic system for electric motors, such as those used in automotive applications. The system comprises a controller for supplying a desired command current to said electric motor, a sensor for measuring the rotational speed of the motor, a sensor for measuring the actual current supplied to the motor by the controller, a diagnostic control unit adapted to receive the measured rotational speed, measured supplied voltage, and a command current level value as inputs. The diagnostic control unit further comprises circuitry to calculate an estimated actual current drawn by the motor and to signal an error condition if the estimated actual current is not within a calculated valid range.

Abstract: An improved motor commutation pulse detection circuit for comparing a filtered motor current signal to a threshold value, where the circuit is responsive to the actual or expected amplitude of the commutation pulses for adjusting the motor current signal or the threshold value so that the compared threshold value is substantially equal in amplitude to minimum amplitude commutation pulses in the compared motor current signal. In one circuit, the threshold value is varied in accordance with the average current flowing through the motor at the time of the commutation event. In another circuit, the threshold is effectively switched between a high value and a low value depending on the mode of operation of the motor. A motor run detection threshold is activated during motor running periods, while a motor brake detection threshold is activated during motor braking.

Abstract: A wireless battery-operated window covering assembly is disclosed. The window covering has a head rail in which all the components are housed. These include a battery pack, an interface module including an IR receiver and a manual switch, a processor board including control circuitry, motor, drive gear, and a rotatably mounted reel on which lift cords wind and unwind a collapsible shade. The circuitry allows for dual-mode IR receiver operation and a multi-sensor polling scheme, both of which are configured to prolong battery life. Included among these sensors is a lift cord detector which gauges shade status to control the raising and lowering of the shade, and a rotation sensor which, in conjunction with internal registers and counters keeps track of travel limits and shade position.

Abstract: A motor for use with a power supply comprising a stator, a rotor in magnetic coupling relation to the stator, a plurality of insulated gate bipolar transistors (IGBTs), a user interface, a microcontroller and an application specific integrated circuit (ASIC). Each IGBT has a control input port and is connected between the stator and the power supply for selectively applying power to the stator in response to a control signal applied to the control input port. The user interface provides user signals indicative of one or more desired operating parameters of the motor. The microcontroller has control inputs receiving the user signals and has low voltage output ports for providing low voltage output signals for commutating the stator as a function of the user signals. The ASIC has low voltage input ports connected to the low voltage output ports of the microcontroller and has high voltage output ports connected to the control input ports of the IGBTs.

Abstract: A motor overload coil control is disclosed for use in a motor starter/relay contactor. The control includes an 8-bit, 8-pin microcontroller that together with an I/O reduction circuit, is capable of functioning 13 I/O's with only 5 I/O pins on the microcontroller. Three remote signals are prioritized and reduced on one input line to the microcontroller. The control includes three-phase current measurement from three Hall effect current sensors positioned one on each leg. The system includes current integration to provide a single current input to the microcontroller. A full load amperage (FLA) adjustment allows use on a wide range of motors. The microcontroller uses the FLA adjustment and the current signal to find an appropriate I2t value for real-time monitoring of the operating temperature of the motor. A status indicator is provided having an LED output to show the status of the system and indicate the motor temperature, when appropriate.

Abstract: A method of controlling the torque of a rotary machine powered by means of an inverter and servo-controlled by a system having sensors, an observer, and a computer which delivers controls to the switches of the inverter on the basis of values supplied to the observer by the sensors, in the form of sequences of three vectors to bring the torque &Ggr; and the stator flux &PHgr;S of the machine towards reference values for &Ggr;ref and &PHgr;Sref. The measurement sampling period is selected to be equal to the sequence period DTML which corresponds to half the switching period of the inverter.

Abstract: In a controller, for use in an electric motor, which self-contains a current control system, a conducting portion of a feedback element from a current detector up to a summing point, and a conducting portion of a forward element from the summing point for the current control up to a gate terminal of each of switching devices are mounted in a power module to be hermetically encapsulated without being exposed to the external ambient atmosphere. The distributed processing is executed in the two portions, i.e., a current control loop, and a position control unit, a velocity control unit and an interface processing unit other than the current control loop. Therefore, the current control loop including the current feedback portion is constituted by another sub-microprocessor to be mounted together with the associated devices in a power module which is molded with resin such as epoxy resin.