Denso Corporation

Nippon Soken, Inc.

Other

Toyota Jidosha Kabushiki Kaisha

Nippondenso Co., Ltd.

Tsutomu Nakamura

Kenji Takeda

Osamu Shimomura

Takashi Kawashima

Takao Ban

Yoshiyuki Kono

Akitoshi Mizutani

Koichiro Matsumoto

Takashi Hamaoka

Yasuhiro Fukagawa

Masahiko Osada

Takashi Senda

Tatsuya Kitanaka

Toshihisa Ishihara

Ken Tanaka

Shinji Usami

Shinji Hatanaka

Kouichi Osawa

Tetsuo Hariu

Noboru Nagase

Masao Tokunaga

Masaru Kamiya

Michio Furuhashi

Kimio Uchida

Yoshiharu Takeuchi

Taiyo Kawai

Toshio Ito

Nobuo Habu

Hideo Naruse

Takamichi Kamiya

Yuuichi Kato

Tatsuya Kakehi

Junichi Saiki

Hiroshi Takeyama

Hironari Nakagawa

Masaru Touge

Masayuki Kaneko

Yoshikazu Yokochi

Keiichi Yasuda

Kenji Tak Da

A power supply unit superimposes alternating-current voltage on direct-current voltage and applies it to a motor. As a result, when the motor is rotated, a current containing an alternating-current component flows. Further, the motor includes a capacitor connected in parallel with one phase coil. Owing to this capacitor, the impedance of the motor circuit between brushes is varied according to the rotation of the motor. Variation in impedance appears as variation in the amplitude of the alternating-current component in motor current. A signal processing unit extracts an alternating-current component from the motor current detected by the current detection unit and generates a rotation pulse corresponding to variation in the amplitude. A rotation angle detection unit detects the rotation angle of the motor based on this rotation pulse.

Rotation detector and direct-current motor

In a piezoelectric actuator control device for controlling operation of one or more piezoelectric actuators, when receiving a drive signal of a low level, a discharging switch is repeatedly turned on and off in order to discharge electric charge accumulated in the piezoelectric actuator. That is, the discharging switch is kept ON until a discharging current from a piezoelectric actuator reaches a peak threshold value Ip. When the discharging current reaches the peak threshold value Ip, the discharging switch is turned OFF and kept OFF until a discharging current from a piezoelectric actuator reaches a peak threshold value Ip. The device has a threshold value setting circuit for increasing the peak threshold value according to a discharging period of time.

Piezoelectric actuator drive device

A turbine wheel of a turbocharger has a turbine blade. The turbine blade has a fin shape of which width in the rotation direction of the turbocharger is narrow, and is projected from the base portion of the turbine wheel. An inclined part of the turbine blade is inclined with respect to the rotation direction of the turbocharger. A coil is disposed so that the inclined part passes nearby as the turbine wheel rotates in a posture that an end in the center axis direction is directed toward the turbocharger. A detector detects a change in inductance, which occurs when the inclined part of the coil passes nearby.

Motion detecting apparatus

An eddy current type sensor for detecting a conductor includes a LC circuit and an oscillator. The LC circuit has a coil and a capacitor connected in parallel with the coil. The oscillator supplies an alternating current of a predetermined oscillation frequency to the LC circuit. A signal voltage outputted from the LC circuit has a first voltage when the distance between the coil and the conductor is minimum and a second voltage when the distance between the coil and the conductor is maximum. A voltage difference between the first and second voltages has a first difference at a first temperature and has a second difference at a second temperature. The first and second differences become equal to each other at a first frequency and a second frequency. The oscillation frequency is set close to the first frequency or the second frequency.

Eddy current type sensor for detecting conductor

A rotation angle detecting device that detects a rotation angle of a rotating object includes a permanent magnet that generates magnetic fields in response to rotation of the rotating object, a magnetic sensor, a first yoke and a second yoke. The magnetic sensor includes a pair of close integrated magnetic sensing elements, such as hall elements, disposed at a position around the permanent magnet so that one of the sensing elements senses magnetic field at a phase different from the other. The first yoke and the second yoke forms two magnetic paths crossing each other at the magnetic sensor.

Rotation angle using orthogonal magnetic sensing elements in close proximity to each other

In a driving device for a piezoelectric actuator, when a driving signal is input, a charging switch is repetitively turned on/off to charge and expand the piezoelectric actuator under the state that a discharging switch is turned off. Thereafter, when the input of the driving signal is stopped, the discharging switch is repetitively turned on/off under the state that the charging switch is turned off, thereby discharging and contracting the piezoelectric actuator. Particularly, during the charging period, the charging switch is turned on at a fixed period, and the charging switch is turned off when an integration value of current flowing in a charging circuit at the ON-time of the charging switch reaches a target charge amount.

Driving device for piezoelectric actuator

In a data processor for processing pieces of input data successively sampled, a memory unit and a plurality of data transferring units for transferring data are provided. Each of the plurality of data transferring units has an upper limit number of data items successively transferable when activated. An activating unit is provided. The activating unit is configured to successively activate, within a predetermined time frame, the data transferring units without all of the data transferring units being deactivated within the predetermined time frame to thereby successively transfer the pieces of input data to the memory unit so as to store the pieces of input data therein.

Data processor for processing pieces of data being successively sampled at intervals

External magnetic members are provided outside the outer periphery of a rotor. When the rotor is positioned around its turning angle of 70 degrees, part of the magnetic fluxes generated by magnets pass through the external magnetic members. This makes it possible to reduce the magnetic fluxes passing through Hall ICs around the turning angle of 70 degrees, thereby linearizing the change characteristic of the magnetic flux density. Thus, it is possible to generally linearize the change characteristic of the density of the magnetic fluxes through the Hall ICs, with the detectable angle range kept wide.

Turning angle detector

A rotation angle detector for detecting change in the magnetic flux has a magnetic sensor being disposed at a position in a space between an outer surface of a shaft and a periphery of the magnetic flux generation means. A supplementary magnet is also used in a space that is enclosed in a circular trace of the magnetic sensor around the shaft for even distribution of the magnetic flux generated by the magnetic flux generation means.

Rotation angle detector

An improved rotation angle detecting device that detects a rotation angle of a first member relative to a second member is proposed. The rotation angle detecting device includes a magnet unit fixed to the first member and a pair of magnetic sensors fixed to the second member to provide output signals whose phase is different from each other at 90 degrees in angle. The magnet unit includes a pair of disk plates that has the same magnetic poles at the same circumferential positions and is disposed at a prescribed axial distance and a shaft that is made of magnetic material to support the disk plates at the center thereof. The magnetic unit provides a uniform magnetic field in a space around the shaft between the pair of disk plates, and a pair of magnetic sensors is disposed in the space.

Rotation angle detecting device

An engine starter includes a starter motor which has an armature, a series-wound field coil and a parallel-wound field coil and a short-circuiting unit for short-circuiting the series-wound field coil under a predetermined engine starting condition. The series-wound field coil has a suitable current limiting resistance. The short-circuiting unit short-circuits the series-wound field coil after a crankshaft of an engine passes a first top dead center of an engine.

Engine starter having starter motor

A rotation angle sensing device for detecting a relative rotation angle between a rotor and a stator includes main magnets, fixed in the rotor, and hole ICs, fixed in the stator. The hole ICs detect magnetic flux of the main magnets , and the relative rotation angle therebetween is detected. A supportive magnet is disposed between the hole ICs so as to offset the magnetic flux of the main magnets. Accordingly, a rotation angle in which the magnetic flux density detected in the hole ICs becomes 0 [mT] can be changed by the supportive magnet. Therefore, a 0&#xb0; position of the rotation angle can be set to the rotation angle in which the magnetic flux density is detected as 0 [mT], and moreover the detectable range of the rotation angle can be enlarged to be more than 90&#xb0;.

Rotation angle sensing device having enlarged detectable angle range

A displacement sensor precisely detects displacement of a moving body in a rectilinear movement direction even if the moving body rotates. The sensor includes a detector and a magnet. The cross sectional area of the permanent magnet in a plane perpendicular to an axis, which extends in the rectilinear movement direction, varies in the direction of movement. The permanent magnet is magnetized in the rectilinear movement direction. The detector is located so that magnetic flux passes through a detection face of the detector substantially perpendicularly.

Displacement sensor

An angular position detecting apparatus using a magnetic detecting element, which can voluntary widely set an output change characteristic of the magnetic detecting element with respect to angular positions. An angular position detecting apparatus includes a cylindrical yoke, and a magnet fixed to a predetermined position in the cylindrical yoke. A magnetic detecting element, which is fixed to a rotor, is provided in a magnetic field generated between the magnet and the cylindrical yoke, so that a position of the magnetic detecting element is shifted from a rotation axis P of the rotor by a predetermined distance r. A ferromagnetic thin film magnetic resistance element applies a magnetic field which has intensity so that outputs from the elements are saturated. As a result, the magnetic detecting element generates outputs depending only on a magnetic flux detection angle &thgr;s independent of an influence of changes of magnetic field intensity due to temperature changes. In this case, when at least one of a rotation radius r of the magnetic detecting element and a radius R of the cylindrical yoke is voluntary determined, an output change characteristic of the magnetic detecting element can be voluntary set.

Angular position detecting apparatus for linearly detecting angular position in a wider range

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Kariya, Japan

Tsutomu Nakamura