Abstract: Embodiments of the invention provide a control system for a garage door. The control system can include a motor, a pulley, a synchronous drive member, a carriage, and an operator. The pulley can be coupled to and driven by the motor. The synchronous drive member can be coupled to the pulley and driven by the pulley. The carriage can be coupled to the synchronous drive member and to a bottom edge of a garage door. The operator can be coupled to the motor and can control the motor. The operator can be mounted vertically adjacent to the garage door when the garage door is in a closed position.

Abstract: A method for controlling a motor (11) driving a pump (10) using a microcomputer (14) includes repeatedly sampling a parameter representative of motor torque over one cycle of operation of the pump (10), determining at least one point of maximum motor torque during said one cycle of operation of the pump (FIG. 4); applying speed commands to the motor (11) from a table of stored speed values in memory (19), said values being selected to provide relatively greater speed commands at points of lower motor torque and relatively lesser speed commands at points of higher pump pressure corresponding to higher motor torque, while maintaining at least a base speed command to prevent stalling; and synchronizing the first value in the table of stored values to the point of maximum motor torque.

Abstract: A brushless d.c. motor is integrated with a conveyor roller (14) by placing a plurality of stator coils (15) on a stationary shaft (18) and securing a rotor (10) with segments (12) of permanent magnetic material to the inside of the conveyor roller (14). In one embodiment the rotor (10) is directly secured to the roller while in a second embodiment, the rotor (10) is disposed inside of a cylindrical metal housing (40) that is press fit inside of the roller. Commutation is provided by an external motor controller (54) which is connected by conductors (37) through a passageway (36) in the shaft (18) to a circuit board (20), where sensors (23) are mounted to sense rotor position for purposes of commutation of the stator coils (15).

Abstract: A method and apparatus for controlling the output function of a permanent magnet brushless DC motor (20), by sensing an input current to the motor (20), by computing an output torque generated by the motor (20) as a function of the input current to the motor (20), by computing an output pressure for a pump (22) in response to the output torque, by reading a set point pressure, and by comparing the set point pressure to the output pressure, and in response thereto controlling on-off operation of the motor (20). The apparatus includes a sensing circuit (28) and a microelectronic processor (30) for performing these functions.

Abstract: A digital signal processor for closed loop velocity or position control receives sine winding output signals and cosine winding output signal from a resolver, digitizes the signals and outputs quadrature encoded signals to an excitation circuit. The excitation circuit is connected to an excitation winding in the resolver to provide signals for driving the resolver.

Abstract: A resolver (20, 21) is provided with redundant excitation windings in which only a single excitation winding (E1) is energized externally. Cross coupling from the externally energized winding (E1) excites the other excitation winding (E2). A control circuit (27, 28) monitors the excitation of the redundant excitation winding (E2) and switches the excitation to the redundant excitation winding (E2) in the event of a failure of the externally winding (E1).

Abstract: A resolver (10) is excited with a high frequency signal from excitation circuit (16). Outputs of the resolver (10) are transmitted through receiver circuit (24) and input to a DSP signal processing circuit (18), which demodulates the sine and cosine outputs to provide samples of the sine and cosine of the rotor position. The sample values are converted to digital values, which are used to calculate a shaft angular position, which is then used for closed loop position and velocity control of a brushless PM motor (14).