Abstract: A method for controlling a motorized barrier operator after detecting an obstruction includes the steps of providing a motorized barrier operator that moves a barrier between limit positions and providing at least one control switch that upon actuation moves the barrier in a direction toward one of the limit positions. Actuation of the at least one control switch during movement of the barriers at least causes the barrier to stop. If an obstruction is detected by the motorized barrier operator during movement of the barrier, the operator allows only uni-directional movement of the barrier, regardless of actuation of the at least one control switch, after the detecting step.

Abstract: A method for driving a neutral point-clamped multi-level voltage source inverter supplying a synchronous motor is provided. A DC current is received at a neutral point-clamped multi-level voltage source inverter. The inverter has first, second, and third output nodes. The inverter also has a plurality of switches. A desired speed of a synchronous motor connected to the inverter by the first second and third nodes is received by the inverter. The synchronous motor has a rotor and the speed of the motor is defined by the rotational rate of the rotor. A position of the rotor is sensed, current flowing to the motor out of at least two of the first, second, and third output nodes is sensed, and predetermined switches are automatically activated by the inverter responsive to the sensed rotor position, the sensed current, and the desired speed.

Abstract: In an automatic transmission position control by a motor, it is determined whether the present instant belongs to a starting period, that is, the present instant is immediately after resetting of a control unit or application of power to it. If it is the starting period, an actual shift position that is detected from an output of an output shaft sensor for detecting a rotation position of a motor is set as an instructed shift position. With this measure, even if the control unit is reset for a certain reason while the vehicle is running, the instructed shift position is not changed in association with the resetting. This prevents trouble that the shift position is switched contrary to the intention of the driver, whereby the reliability of a position switching control can be increased.

Abstract: A braking device for an electric motor of a power tool has a short circuit switch for short circuiting an armature winding of the electric motor during a braking process, the short circuit switch for controlling its switch condition having a control input, a control unit connected with the control input of the short circuit switch for performing a phase control of the short circuit switching during the braking process in order to avoid brush fire; also an electrical device with such a braking device and a braking method are proposed as well.

Abstract: In an automotive power window system, a controller detects positions of a window glass that moves through driving operation of a motor during the closing operation of a window. The controller reduces a rotation speed of the motor when the window glass reaches a speed altering position. It calculates the amount of reduction in the rotation speed produced by the rotation speed reducing operation. Then, it corrects a rotation speed obtained during the closing operation by compensating for the amount of reduction. It determines whether an obstruction for the closing operation is present based on the corrected rotation speed. If the obstruction is detected, it controls the motor for releasing the obstruction.

Abstract: A control apparatus for a brushless DC motor that rotatably drives the brushless DC motor including a rotor having a permanent magnet, and a stator having stator windings of a plurality of phases that generate a rotating magnetic field for rotating the rotor, by a current passage switching device constituted by a plurality of switching elements and performing successive commutation of current to the stator windings. The control apparatus includes: an angular error calculation device for calculating a sine value and a cosine value of an angular difference between an estimated rotation angle with respect to the rotation angle of the rotor and an actual rotation angle, based on a line voltage that is a difference between phase voltages of the plurality of phases on an input side of the stator winding and phase currents of the plurality of phases; and an observer for calculating the rotation angle of the rotor based on the sine value and the cosine value of the angular difference.

Abstract: Three rotation sensors circumferentially arranged at 90 degree intervals in a disk code wheel attached to a motor's output shaft respectively output a signal corresponding the rotational speed of the wheel. An error component of one period (one-periodic component) or an error component of two period (two-periodic component) is generated per rotation when the code wheel is eccentric to the output shaft or is elliptically deformed, respectively. Control means averages the signals of the first and second sensors to obtain a first correction signal and subtracts the signal of the third sensor from the signal of the first sensor to obtain a second correction signal while removing the two-periodic component. The control means subtracts or adds the first correction signal relative to the second correction signal upon coinciding these signals in phase and amplitude to calculate a rotation measurement signal from which the periodic components are removed.

Abstract: Method and apparatus for accelerating a motor from an intermediate velocity to a final operational velocity. The motor is accelerated from rest to the intermediate velocity through application of fixed duration drive pulses to the spindle motor. Once the motor reaches the intermediate velocity, commutation circuitry and back electromotive force (bemf) detection circuitry use detected bemf from the motor to electronically commutate the motor to accelerate to the final operational speed. A phase lock oscillator (PLO) attempts to acquire frequency lock for the motor. A control circuit measures the current in the motor to evaluate the effectiveness of the phase lock. If the measured current is found to be above a threshold value, the motor is restarted.

Abstract: A motor starter for use with a motor (20) having a main winding (M) and a start winding (S). The starter has a PTC thermistor (30) connected in series with the start winding (S). A triac (40) is connected between PTC thermistor (30) and a power source line. A control circuit (50) is connected to the power source line for providing a voltage for a gate terminal (G) of triac (40) and an overload relay (60) is connected between the power source (10) and the motor (20). The control circuit (50) preferably includes a current detecting circuit (52) for detecting the inrush current and a voltage generating circuit (54) for generating the voltage in response to the detected inrush current. At the startup of motor (20) the control circuit (50) allows triac (40) to turn on by providing the gate terminal (G) with the voltage based on the inrush current. According to this invention, the power consumption of the start winding S after the startup of the motor (20) can be almost zero thus providing low power consumption.

Abstract: A keyboard apparatus is provided with a key unit that has a plurality of keys supported for pivotal motion. Also provided is a detection section for detecting a key speed when any of the keys are pivoted. The key unit and detection section are supported by a housing having a bottom member formed of a resin. A reinforcing member having a sufficient rigidity is provided to reinforce the bottom member of the housing such as to reduce warping of the bottom member so as to reduce movement of the detection section as a result of warping of the bottom member.

Abstract: Frets can be provided for stringed instruments without requiring a process for scraping both ends of a fret main body after the frets are installed into a fingerboard of a stringed instrument. Both ends of the fret main body are formed in a shape along a cross-sectional shape of the fingerboard at both sides of the fingerboard when the frets are driven into fret grooves of a fingerboard. Each of the frets is provided with a fret main body for dividing a surface of the fingerboard and a leg portion standing unitedly on an underside of the fret main body.

Abstract: A method and an apparatus for precisely controlling the rotation speed of a spindle motor in an optical system according to a given condition are provided. The method involves counting in response to a clock signal widths of first and second logic states of an input signal, which varies with rotation speed of the spindle motor, when an operation control command is issued, comparing a predetermined reference value with a count value for one check cycle, and outputting the comparison result; and controlling the constant linear velocity of the spindle motor in response to the comparison result.

Abstract: An automobile servomotor controller includes a master control unit having a master control circuit for transmitting a designation signal and a slave unit having a motor and a control circuit which controls driving of a motor by outputting an operation signal to a driving device depending upon said designation signal. The slave unit is constructed by a same feedback control unit having a non-feedback control unit for inhibiting the operation of the motor until a target is changed by an input of a new designation signal with a target reached state and a feedback control unit for driving the motor to reach a target state by detecting a present position value with a position detecting device, and a control inhibiting signal for inhibiting the feedback control is individually provided to the designation signal transmitted from the master control circuit to the non-feedback control unit.

Abstract: A system for controlling the speed of a brushless repulsion motor having a series of switches mounted on a rotating armature for shorting circumferentially spaced armature coils comprising first stationary signaling means and a plurality of rotating detectors for activating said switches; second stationary signaling means for speed control; a plurality of markers on the rotating armature; a speed detector for detecting the speed of the rotating markers and generating a speed feedback signal; means for generating a speed command signal; an error calculator for comparing the speed feedback and speed command signals and generating an error signal; and a controller for controlling the signaling means based on the error signal.

Abstract: This device (1) enables the user to personalize the call signal (ringing) which it is called on to deliver. This personalization consists of transforming a melody (FIG. 1) which the user hums into his microphone in order to transform it into a polyphonic melody (FIG. 8). Application: Ringing for mobile telephones.

Abstract: It is an object of the invention to provide a technique to effectively prevent a power tool from being adversely affected when a battery is removed from the power tool. According to the present invention, a power tool is provided that includes a tool bit, a motor that drives the tool bit, a body that houses the motor, a battery detachably coupled to the body so as to supply driving current to operate the motor, a control device that controls the operation of the motor and a power circuit that leads the driving current from the battery to the motor. Within the power tool, the control device stops the motor prior to an interruption of the power circuit when the battery is disengaged from the body in order to prevent a large driving current from being passed through the power circuit. As a result, arc can be effectively prevented from being generated between the battery and the body of the power tool.

Abstract: A motor drive apparatus which drives a motor by controlling conduction/non-conduction of a drive transistor for causing a current to flow through a drive coil of the motor based on a pulse signal indicating a relative position between the rotor and stator of the motor, generated by a position detector, and on a rotation speed setting voltage for setting the rotation speed of the motor. The apparatus comprises a control circuit that generates a pulse-delayed signal by delaying the pulse signal by delay time according to the voltage level of the rotation speed setting voltage.

Abstract: A unipolar drive includes a booster, an energy storage module, and a unipolar inverter. The booster increase a voltage received from a power supply to produce an energy output. The energy storage module store at least some of the energy output by the booster. The unipolar inverter energizes windings of a motor using energy from the booster and returns energy from the windings to the booster when the windings are not being energized.

Abstract: A carrier signal generation section is provided for each of U, V, and W phases, and each of the carrier signal generation sections has an up-down counter for counting clock signals output from a clock generator. An initial value is set for each of the up-down counters. When the up-down counters are simultaneously started by method of a count start signal output from a CPU, the respective up-down counters start counting operations from the respective initial values, perform cumulative subtraction until the count value reaches an upper limit, and perform cumulative addition until the count value reaches a lower limit. As a result, triangular wave carrier signals Cu, Cv and Cw of respective phases having a predetermined phase difference can be readily generated with high accuracy.

Abstract: An interrupt signal is generated at each of rising timings of PWM signals which are produced on the basis of phase-shifted triangular wave carrier signals for phases, and voltage command values for the phases. At timings of the interrupt signals, A/D conversion of motor currents of the phases detected by a shunt is started. Interrupt signals are also produced at timings of valleys of the triangular wave carrier signals. Additionally, peak interrupt signals and valley interrupt signals are respectively produced at timings of peaks and valleys of triangular wave carrier signals for phases. Based on each of the peak interrupt signals, normality/abnormality of a switching element of an upper side of the phase corresponding to the interrupt signal is checked, and, based on each of the valley interrupt signals, normality/abnormality of a switching element of a lower side of the phase corresponding to the interrupt signal is checked.