Abstract: Methods and apparatus for controlling a motor are provided. The motor may be operated in a fluid system having a variable static pressure acting on the motor. The method including operating the motor at a first substantially constant torque level, varying the static pressure of the system, receiving a torque selection signal from external to the motor, and operating the motor at a second substantially constant torque level, the level corresponding to the torque selection signal.

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: A permanent magnet DC brushless motor control assembly permits a user to select the permanent magnet DC brushless motor operating characteristics by selecting appropriate control circuits to interface with the motor. The assembly includes a permanent magnet DC brushless motor, a commutator electrically coupled to the motor, and at least one control module electrically coupled to the commutator, to control operating characteristics of the permanent magnet DC brushless motor.

Abstract: A permanent magnet DC brushless motor control assembly permits a user to select the permanent magnet DC brushless motor operating characteristics by selecting appropriate control circuits to interface with the motor. The assembly includes a permanent magnet DC brushless motor, a commutator electrically coupled to the motor, and at least one control module electrically coupled to the commutator, to control operating characteristics of the permanent magnet DC brushless motor.

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 having a rotor and stator for use with a power supply. A power switching circuit connected between the windings and the power supply selectively energizes windings of the stator to generate the magnetic field applied to the rotor to cause the rotor to rotate. A microprocessor circuit including a microprocessor controls the power switching circuit. A module having a module circuit controls the operation of the microprocessor circuit. A module connector connected to the microprocessor circuit releaseably receives the module. The module connector is within a housing and receives the module and connects the module circuit to the microprocessor circuit. The microprocessor circuit is responsive to the module circuit for controlling the power switching circuit as a function of the module circuit, whereby the operation of the motor is a function of the module 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: A motor having a stationary assembly including a winding and a rotatable assembly in magnetic coupling relation to the stationary assembly. A bridge circuit for use in driving the motor has upper and lower power switches connected between the winding and the upper and lower rails, respectively, of a power supply link. Each of the lower switches corresponds to one of the upper switches and each of the switches has a conducting state and a nonconducting state. The motor also has a control circuit for generating a motor control signal to control the switches. The lower switches are receiving and responsive to the motor control signal. A drive circuit drives the upper switches in response to the state of the lower switches to selectively connect the rails of the power supply link to the winding. As such, the winding is energized to produce an electromagnetic field for rotating the rotatable assembly relative to the stationary assembly.

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 system for driving a blower of a heating, ventilating, and/or air conditioning (HVAC) system. The blower discharges heated or cooled air to a space for conditioning the air in the space by changing its temperature. A motor drives the blower at a speed or torque defined by a motor control signal thereby to control air flow rate of the HVAC system. The system includes a temperature sensor generating a temperature signal representative of the temperature of the air discharged to the space by the blower. In response to the temperature signal, a control circuit generates the motor control signal to cause the motor to operate at a minimum speed or torque until the temperature of the discharged air as represented by the temperature signal reaches a reference temperature.

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).

Abstract: A motor assembly includes a stationary assembly having a plurality of winding stages adapted to be electrically energized to generate an electromagnetic field and a rotatable assembly including a plurality of permanent magnet elements in magnetic coupling relation with the stationary assembly. The motor assembly also includes first and second substantially flat end members parallel to each other and having inner facing sides between which the stationary assembly and the rotatable assembly are located. Each of the members has an outer side opposite its inner side. Control circuitry is connected to the winding stages and positioned adjacent the outer side of the first member, for applying a voltage to one or more of the winding stages at a time and for commutating the winding stages in a preselected sequence to rotate the rotatable assembly about an axis of rotation. A cap on the outer side of the first member forms a closure with the first member within which the control circuitry is located.

Abstract: Apparatus and method for generating a sensing signal which is a function of a direct current flowing in a particular direction in a conductor. A core inductively coupled to the conductor is subject to negative magnetic saturation after a period of time as a result of a magnetic field generated by the direct current in the conductor. The aforesaid period of time is a function of the magnitude of the magnetic field generated by the direct current flowing in the conductor. An output winding around the core produces an output signal which is a function of the direct current in the conductor when the core is not saturated but which is not a function of the direct current in the conductor after the aforesaid period of time. A reset winding is periodically driven by a pulse to reset the magnetic orientation of the core to positive magnetic saturation before the aforesaid period of time elapses.

Abstract: Electronic control circuit for use with electrical load powering apparatus having a load connection, a high voltage supply connection and a common, and with an electronic switch to switch the high voltage supply connection to the load connection. The electronic switch has an input and is responsive to a voltage difference between the input and the load connection. The load connection is subject to high voltage excursions relative to the common due to the switching. The electronic control circuit includes a transformer having a primary winding and a secondary winding for providing at least one pulse output from the secondary winding, the transformer having an inherent interwinding capacitance between the primary winding and the secondary winding. A circuit connected to the secondary winding couples the pulse output from the secondary winding between the input of the electronic means and the load connection when the pulse output is present.

Abstract: Electrical load powering apparatus has a load connection, a high voltage supply connection and a common, and includes electronic means for switching the high voltage supply connection to the load connection. The electronic switching means has an input and is responsive to a control voltage difference between the input and the load connection. The load connection is subject to high voltage excursions relative to the common due to the switching. An electronic control circuit for use in the electrical load powering apparatus includes a circuit having an active device for providing at least one pulse output relative to common and having at least one inherent capacitance. A circuit connected to the load connection inverts the pulse output of the circuit having the active device to produce the control voltage difference between the electronic switching means input and the load connection.

Abstract: An improved snubber circuit for a bipolar switching transistor connected to drive an inductive transformer load comprises a first resonant circuit connected to the driven winding of the transformer and a second resonant circuit connected to a clamp winding of the transformer. At turn-off, the two resonant circuits provde an alternate current path for inductive currents to thereby limit the voltage applied to the load transistor. The circuit are interconnected to minimize component count in a manner which permits resetting the capacitive components to improve snubbing capability.

Abstract: An improved proportional base drive circuit for rapidly and efficiently switching a high current bipolar transistor includes a transformer having first and second serially connected windings coupled in a load current path between the emitter terminal of the transistor and a load. A base terminal of the transistor is connected to a junction intermediate the two windings by a base bias circuit. The turns ratio between the two windings is selected to force a proportional base current to flow to the transistor. A third winding is provided, along with switching apparatus for exciting the third winding, whereby conduction of the load transistor can be initiated by energizing the third winding. A diverter circuit connected to the third winding allows rapid removal of current from the base of the load transistor for fast turn-off. In an alternative embodiment, a fourth winding is arranged to provide a driving current for more rapid forcing of current from the base drive circuit at turn-off.

Abstract: A half-bridge inverter having first and second power FETs is provided with a high-speed, highly efficient drive circuit for driving the FETs from a single control signal. A single 15 V supply provides energy for charging the gate electrode of the first FET, as well as for a floating source for charging the gate electrode of the second FET. A single bipolar transistor receives the control signal for controlling operation of the first FET, while a current source, a bipolar transistor in series with a resistor, receives the control signal to effect operation of a third bipolar transistor, thereby to control operation of the second FET.