Abstract: A serial interface circuit electrically connected to a controller to control an electric motor. The interface circuit includes a controller circuit and a motor circuit. The controller circuit includes a transmitter and a receiver circuit, and the motor circuit includes a transmitter circuit and a receiver circuit. The interface interrogates the motor to acquire status and diagnostic information by receiving commands from the controller, adjusts a voltage level to a desired level, outputs the voltage signal to command and control the motor, and receives a voltage response from the motor.

Abstract: Methods and control systems for improving performance in an air filtration system are disclosed. The method includes monitoring performance of a blower motor in the air filtration system and adjusting blower motor torque based upon a measured airflow or a measured static air pressure within the air filtration system.

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 which has a first motor winding that provides a motor back EMF during operation of the motor, and which is operable by a supply current to develop, at a predetermined nominal rotational speed, a predetermined nominal torque corresponding to a predetermined operating current and a predetermined nominal back EMF, is calibrated by applying a supply current to the motor such that the motor operates at a known rotational speed, disconnecting the supply current from the motor such that the motor decelerates from the known rotational speed, and obtaining an EMF indication of motor back EMF. The EMF indication is compared with the predetermined nominal back EMF, and a supply current adjustment that provides for compensation of the supply current based on the EMF indication and the predetermined nominal back EMF is developed, such that the motor produces the predetermined nominal amount of torque when operated at the predetermined nominal rotational speed.

Abstract: A motor with a switching power converter is connected to a power source for supplying power to the motor. The converter has a motor terminal selectively connected to a voltage bus. A stator core has a stator body supporting a plurality of poles. A rotor is in magnetic coupling relationship with the stator core. A stator winding has a first termination and a second termination and is wound on one of the poles such that the first termination is closer to the one pole than the second termination. The first termination is electrically connected to a neutral terminal. The second termination is electrically connected to the motor terminal of the switching power converter. Parasitic capacitance associated with the second termination and EMI caused by such parasitic capacitance is minimized as compared to the parasitic capacitance occurring if the second termination is connected to the neutral terminal and the first termination is connected to the motor terminal. A method of assembling is also described.

Abstract: A motor system and method providing improved power factor and harmonic control of power supplied to a motor. The system and method employs a power conversion circuit connected to an AC voltage source for supplying power to a power supply link of the motor. The power conversion circuit includes a rectifier circuit and a power factor correction circuit. The rectifier circuit rectifies the AC voltage and has first and second outputs corresponding to upper and lower rails of the power supply link, respectively. The power factor correction circuit is connected directly between the first output of the rectifier circuit and a node of the corresponding upper rail of the power supply link for improving the power factor of the power supplied to the motor.

Abstract: A single phase permanent magnet motor includes a rotor, a stator, and a quadrature axis winding positioned out-of-phase from a main winding of the stator for generating an output signal representative of rotor angular position. An integrator can be coupled to the quadrature axis winding for phase retarding the output signal, and a comparator can be coupled to the integrator for detecting zero crossings of the phase retarded output signal to provide a commutation signal. The quadrature axis winding can be positioned about ninety electrical degrees out-of-phase from the main winding of the stator, and the integrator can be adapted to phase retard the output signal by a number of degrees which decreases as a speed of the motor increases. At low speeds the phase retard is preferably at about ninety degrees so that the phase retarded signal becomes in-phase with the main stator winding back EMF voltage.

Abstract: A power supply for supplying power from a direct current (DC) source to a load. A load control circuit connected to the load and connected to the DC source regulates a voltage applied to the load. An inductive circuit connected to the load control circuit supplies power to the load. A switching circuit is connected between the DC source and the inductive circuit and responds to the inductive circuit. The inductive circuit supplies power to the switching circuit and controls the switching circuit to selectively connect the DC source to the inductive circuit.

Abstract: A single phase permanent magnet motor includes a rotor, a stator, and a quadrature axis winding positioned out-of-phase from a main winding of the stator for generating an output signal representative of rotor angular position. An integrator can be coupled to the quadrature axis winding for phase retarding the output signal, and a comparator can be coupled to the integrator for detecting zero crossings of the phase retarded output signal to provide a commutation signal. The quadrature axis winding can be positioned about ninety electrical degrees out-of-phase from the main winding of the stator, and the integrator can be adapted to phase retard the output signal by a number of degrees which decreases as a speed of the motor increases. At low speeds the phase retard is preferably at about ninety degrees so that the phase retarded signal becomes in-phase with the main stator winding back EMF voltage.

Abstract: An apparatus for use with a refrigeration system including a compressor for compressing a working fluid evaporated in an evaporator and condensed in a condenser. A control circuit initiates operation of a refrigeration cycle and initiates a defrost cycle in response to a defrost enable signal. The apparatus drives an air moving assembly moving air over the evaporator. A motor including a rotatable assembly is in driving relation to the air moving assembly. An energizing circuit selectively energizes the motor in response to the control circuit. A sensing circuit generates a speed/torque signal representative of a speed or a torque of the motor. A defrost initiating circuit generates the defrost enable signal when the speed/torque signal indicates that the speed is greater than a predetermined speed or the torque is greater than a predetermined torque.

Abstract: A single phase motor system and method for preventing excessive circulating currents in the motor. The motor has a power supply link including power switches responsive to a motor control signal for connecting the motor winding to a power supply in alternating on and off intervals. A current sensing circuit senses current in the power supply link during the on intervals. A current regulation circuit generates a current regulation signal representative of the difference between the sensed current and a peak regulated current level that is a function of desired motor speed and/or torque. An overcurrent circuit generates an overcurrent signal in response to the sensed current exceeding a maximum current level greater than the peak regulated current level. The motor also has a control circuit responsive to the current regulation signal for generating the motor control signal thereby to regulate current in the winding and control the motor speed and/or torque.

Abstract: A system which drives a component of a heating, ventilating, and/or air conditioning (HVAC) system in response to a system control signal such as a temperature signal provided by a thermostat. The system includes a motor having a stationary assembly and a rotatable assembly. The rotatable assembly is in magnetic coupling relation to the stationary assembly and is in driving relation to the component. The motor drives the component in response to a control signal generated by a microprocessor. The microprocessor is responsive to parameters representative of the system and to the system control signal. The parameters are stored in a memory and are defined in response to a parameter select signal. The control signal provided by the microprocessor controls the speed and torque of the motor. The system further includes an instruction memory for storing instructions controlling the operation of the microprocessor.

Abstract: A microcontroller with external memory interacts with a host computer or terminal via a fully isolated RS232 serial interface. An eight-bit D/A converter transforms signals generated digitally in the microcontroller. The low level analog signal at the D/A output is further amplified in a power amplifier which supplies a signal to the motor terminals of the motor to be programmed via solid state relays. The solid state relays form an array of switches which are selectively closed by a low level digit signal generated by the microcontroller and processed by digital circuits. Four signals may be modulated with a signal representing the line frequency and are used specifically in an emulation mode. The interface receives multi-function feedback signals (RPM) from the motor such as speed, memory, content, and diagnostic information. Comparators provide an integrity check of the connections (cable) and the input section of the motor (optocouplers).