Abstract: A brushless dc motor assembly including control electronics for allowing variable speed, user-controlled motor operation. The control electronics are connected to a control board which is mounted directly to the motor bearing bracket. Hall effect devices for providing rotor rotational position information to the electronics are connected directly to the control board and extend therefrom to a position adjacent the rotor. The electronics control current through the stator winding through a MOSFET H-bridge circuit in dependence of feedback signals from the hall effect devices, a user-controlled enable signal, a motor winding current limit signal, and an under voltage signal.

Abstract: A circuit for minimizing the current spikes in through the stator coils in a brushless dc motor is disclosed. The circuit includes a voltage amplifier for receiving an input signal voltage and a feedback voltage, a compensation circuit for compensating the output of the voltage amplifier, a second voltage amplifier for amplifying the compensated output, a switch for selectively connecting compensated output to the stator coils, and a conductive path for discharging the compensation circuit when the switch is not conducting. The conductive path can be a transistor or a transistor in series with a voltage reference device. The invention reduces the commutation noise and the dynamic power requirement in a brushless direct current motor.

Abstract: In order to control the operating voltage of a fan in electrical equipment, the temperature of an output diode (D) of an output circuit of the power supply of the electrical equipment is monitored. The operating voltage of the fan is controlled as a function of the component temperature of this physical element such that up to a limit temperature, which is in the region of the maximum permissible component temperature of a physical element which absolutely becomes the hottest, the operating voltage of the fan is regulated at a constant, minimum level. The operating voltage is then regulated to rise continuously and rapidly up to a maximum operating voltage at which, although the component temperature of the physical element which absolutely becomes the hottest is still above the limit temperature, it is below the maximum permissible component temperature of this physical element, however.

Abstract: A lens controlling apparatus includes a lens-driving stepping motor, a driving current forming circuit for forming a driving current waveform to be supplied to the stepping motor, an inputting circuit for inputting a stop instruction to stop the lens-driving stepping motor, a stopping circuit for performing the operation of stopping the stepping motor in accordance with the stop instruction, a phase detecting circuit for detecting the phase of the driving current waveform to be supplied to the stepping motor, and an inhibiting circuit for inhibiting the stop instruction from being executed except when the phase of the driving current waveform detected by the phase detecting circuit is a predetermined phase.

Abstract: A stage apparatus for moving a table, on which a work is carried, of a semiconductor producing equipment or the like on a base by way of a driving shaft and positioning the table at a predetermined position. The stage apparatus comprises a guide mechanism for guiding and supporting the table on the base; a linear motor provided between the base and the table along a direction in which the table is fed; and controlling means for controlling, for a predetermined period before the table is stopped, stopping operations of the driving shaft and the linear motor in a mutually associated relationship in accordance with predetermined controlling conditions.

Abstract: A motor-driven power steering apparatus comprises: a torque sensor for detecting a steering torque; an assist indicator for outputting an indication signal which indicates the direction and magnitude of an output torque of a motor power-assisting a steering mechanism; a dither signal generator for outputting a high-frequency dither signal; and a control circuit for controlling a current supplied to the motor according to the indication signal provided by the assist indicator and the dither signal provided by the dither signal generator.

Abstract: Method and apparatus for automatically controlling the opening and closing of a door by: (a) ultrasonically monitoring a predetermined approach area located in front of the door for the entry of an object into the approach area and the movement of the object towards the closed door; (b) ultrasonically monitoring a predetermined opening-door protect area laterally outwardly of the outer end of the closed door, and a predetermined closing-door protect area inwardly of the inner end of the door for the presence of an object in the opening-door and closing-door protect areas; and (c) controlling a drive in response to the above monitoring operations.

Abstract: To estimate the rotation speed of the motor for assisting a steering torque regardless of the running state of a vehicle with accuracy, an application voltage estimation value obtained by subtracting a correction voltage obtained based on a detection current value detected by current detection means from the inter-terminal voltage measurement value of the motor is output and the rotation speed of the motor is estimated based on this application voltage estimation value and the detection current value.

Abstract: In a current-limiting setting mode, with, the motor locked and with the accelerator 4 operated fully, the detection current value of the motor provided by a current sensor CT is displayed. The operator, while observing the display, operates up/down push buttons 13 and 14 until the detection current value reaches a predetermined current-limiting value, and a duty of application of current is stored. This feature makes it unnecessary to additionarily provide a current meter, and makes it possible for only one person to perform the adjusting operation.

Abstract: The starting device for a turbine engine unit of a helicopter includes an electric motor starter, supplied from an electrical power source, which can be outside the helicopter and temporarily connected to the starting device through a connection socket, or onboard on the helicopter. The starter is supplied with alternating current and includes an alternating current electric motor, preferably an auto-controlled synchronous motor, and the onboard electrical power source is preferably an alternator driven, during independent starting, from an auxiliary power unit with a turbo-machine and itself started by direct current batteries.

Abstract: A motor controller controls a motor operated by an AC line voltage. The controller includes an SCR connectable between an AC line and a motor terminal for controlling application of AC line voltage to the motor. A voltage sensor is operatively associated with the SCR to sense voltage across the SCR. A control circuit is connected to the sensor and the SCR for varying relative duration of on time and off time during each cycle of line voltage to control motor voltage at a reference level. The control circuit determines if a motor stall condition occurs responsive to the sensed SCR voltage and, in response to determining that a motor stall condition occurs, reducing motor voltage by decreasing duration of on time to protect the solid state switch means SCR.

Abstract: A control circuit for regulating the rotational speed of a DC brushless motor includes an electrical conduction switch having an input, an output and a control terminal for passing a motor supply signal to a DC brushless motor. A voltage averaging circuit generates an averaged signal indicative of the average voltage level being supplied to the motor. The averaging circuit informs an error amplifier to modulate the motor supply signal to compensate for changes in the voltage level of the motor supply signal in order to maintain the rotational speed of the motor at a generally constant rpm. The control circuit takes advantage of the motor windings and rotor mass as a filter circuit to smooth changes in current drawn by the motor, and to further maintain the rotational speed of the motor.

Abstract: A current controller for a switched reluctance machine is disclosed. The current controller controls the switching frequency of the power devices that control the energization of the phase windings of the machine and the peak magnitude of the phase current in response to a single pulse width modulated signal. Also disclosed is a method and circuit for implementing slope compensation in a current controller for a switched reluctance machine where the magnitude of the slope compensation is proportional to the voltage of the power supply from which the phase windings are energized.

Abstract: In controller for diesel electric locomotive, after output from an alternating current generator driven by a diesel engine is rectified into direct current power, the direct current power is inverted into alternating current power by an inverter to thereby carry out a power run control of an induction motor, and energy generated by the induction motor is consumed at a brake resistor by moving a brake chopper when the brake is applied. When a revolving speed of said induction motor exceeds a predetermined value at the time of power run, an slip control unit detects slip of wheels and outputs an output reduction signal for the induction motor in correspondence to a level of slip. An output torque of the induction motor is reduced with the output reduction signal. Further, a reduced amount of the output torque of the induction motor is consumed at a brake resistor through a conduction ratio control of the brake chopper.

Abstract: A method for controlling the starting, stopping and operation of an AC motor is provided. Each winding of the AC motor is interconnected to an AC source by a thyristor switch and a bypass contactor for providing voltage and current to the AC motor. The method includes a steps of sequently firing a pair of tyristor switches to bring the AC motor to full operating speed. Once at operating speed, the bypass contactors are closed. Upon detection of a voltage drop across a thyristor switch, the thyristor switch is fired immediately to transfer motor current from the bypass contactor to the thyristor switch in order to maintain voltage and current to the AC motor.

Abstract: A system for speed-sensorless control of an induction machine includes a flux regulator & torque current calculator for operating the machine in a heavily saturated state to produce a saturation induced saliency; a saliency tracker for tracking an angle of the saturation-induced saliency; a signal injector for injecting an AC signal aligned with a saliency axis; voltage and current determiners for determining stator voltages and currents; and a rotor flux calculator for using the saturation-induced saliency angle, the determined stator voltages, and the determined stator currents to determine a magnitude and a location of a rotor flux vector. The flux regulator & torque current calculator is adapted to use the rotor flux vector to control the induction machine.

Abstract: A hydraulic pump-motor having an end shield which deadens the sound generated by the pump-motor do thereby result in a quieter unit. The present invention provides a conventional hydraulic pump-motor having an electric motor coupled to a pumping mechanism wherein the motor includes an improved sound attenuating end shield design. Through the use of acoustically deadening materials such as cast iron and polypropylene plastic, the end plates of the present invention deaden the sounds stemming from the vibration of the pump-motor. In addition, the present invention provides an end shield design which allows the stator to be secured to the motor housing and the air gap between the rotor and the stator to be precisely measured prior to the installation of the end shield. The present invention therefore results in not only a quieter pump-motor but also a pump-motor with higher machining tolerances, improved efficiency, and lower production and maintenance costs.

Abstract: In an electric motor, a Hall sensor (3) is arranged in the vicinity of the outer circumference of the rotor (2) and of at least one of the permanent magnets (4-7) provided for operationally exciting the electric motor. At least one of the permanent magnets (4-7) is provided for generating the magnetic field inducing the Hall sensor (3). The rotor (2) has rotor teeth (2.1) and/or rotor slots (2.2) on the air-gap side and, in operation, produces magnetic field pulsations in proportion to the rotor speed.

Abstract: A marine seismic source for generating acoustic source energy. A housing has a continuous exterior perimeter which is moveable to displace water. Movement of the housing can be accomplished by providing alternating convex and concave exterior surfaces connected with inflection points. The composite shape provides movement inwardly or outwardly, and can be moved with different types of actuators. Piezoelectric elements can be activated to move the housing surfaces and to change the internal housing volume. The resulting pressure pulse provides acoustic source energy useful for the evaluation of subterranean geologic formations and for other purposes.

Abstract: In a stick (1) for a string instrument bow, comprising fiber-reinforced synthetic material and adapted for receiving a frog and for attaching hair thereto, the product of the mass of the stick (1) alone, in g, times the deflection (D) of the stick alone, which constitutes a measure of the stiffness, in mm, when the stick (1) is supported in its handle region at the stick end (at 3) on the outer side opposite the hair side and at a distance of 130 mm therefrom (at 4) on the hair side or inner side, and when a force (F) acts on the head end (5) corresponding to a mass of 300 g, is, for a violin and viola bow 1000 mm.g at the most, preferably 800 mm.g, for a violoncello bow 700 mm.g at the most, preferably 550 mm.g at the most, and for a double-bass bow 600 mm.g at the most, preferably 450 mm.g at the most, so as to obtain a light-weight, stiff bow for a modified playing technique.