Abstract: A rotation angle detecting device includes magnetic field forming members such as a permanent magnet and a yoke, a plurality of magnetic sensors disposed in the magnetic field to rotate relative to the magnetic field forming members to provide output signals that are 90 degrees in phase different from each other, a judgment level calculating circuit that provides a judgment level based on the output signals and judging circuit that judges the output signals normal if the judgment level is within a prescribed range and not normal if the judgment level is out of the prescribed range.

Abstract: A rotation angle detecting device includes magnetic field forming members such as a permanent magnet and a yoke, a plurality of magnetic sensors disposed in the magnetic field to rotate relative to the magnetic field forming members to provide output signals that are 90 degrees in phase different from each other, a judgment level calculating circuit that provides a judgment level based on the output signals and judging circuit that judges the output signals normal if the judgment level is within a prescribed range and not normal if the judgment level is out of the prescribed range.

Abstract: The control device records, in advance, a current data table which specifies relationships between currents in respective phases in a three-phase motor and rotation angles of a rotor of the three-phase motor, obtains, from the current data table, a rotation angle of the rotor of the three-phase motor corresponding to a current in each phase in the three-phase motor detected by a current sensor before driving of the three-phase motor, and obtains an initial position of the rotor.

Abstract: A misfire detector detects a misfire in a cylinder based on a maximum value and the minimum value of the angular speed. A first crank angle range is defined in such a manner as to include a crank angle in which the angular speed is maximum during a power stroke. A second crank angle range is defined in such a manner as to include a crank angle in which the angular speed is minimum during the power stroke. The maximum value of the angular speed is calculated within the first crank angle range, and the minimum value of the angular speed is calculated within the second crank angle range. The calculated maximum and minimum values are brought close to actual values to enhance a reliability of the misfire detector.

Abstract: 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.

Abstract: An electromechanical conversion device includes an electromechanical conversion unit and a cable, which has a signal wire and a ground wire for grounding the electromechanical conversion unit. The electromechanical conversion unit performs a conversion between a relative movement with respect to a magnetic field generation unit and electrical signals, based on a magnetic field generated by the magnetic field generation unit. The signal wire is connected with the electromechanical conversion unit to transfer the electrical signals, and has a first branch portion and a second branch portion which extend substantially parallel to the ground wire and are respectively arranged at two opposite sides of the ground wire. A distance between the first branch portion and the ground wire is substantially equal to that between the second branch portion and the ground wire.

Abstract: A recording apparatus of a tape-shaped magnetic recording medium includes a transfer unit, a recording head, a signal-processing unit and a control unit. The transfer unit transfers a tape-shaped magnetic recording medium having an anisotropic property oblique with respect to the thickness direction in a forward or reversed direction. The recording head is positioned in such a way that a recording track is formed on the traveling tape-shaped magnetic recording medium, which is transferred by the transfer unit, in a direction parallel to the transfer direction of the tape-shaped magnetic recording medium. Connected to the recording head, the signal-processing unit receives a signal to be recorded onto the tape-shaped magnetic recording medium. The signal-processing unit then carries out signal processing required for an operation to write the signal to be recorded onto the tape-shaped magnetic recording medium.

Abstract: A coil of an electric motor is cooled by refrigerant. A controller for the electric motor controls a current supplied to the coil within a range less than or equal to a predetermined maximum value. A temperature detection section detects either a temperature of the coil or a temperature about the coil. When a detection temperature that is detected by the temperature detection section prior to activation of the electric motor reaches a predetermined reference temperature, a limiting section executes a limiting control to limit an upper limit value of the current supplied to the coil to a limiting value that is less than the maximum value. Accordingly, the coil of the electric motor is protected without stopping the operation of the electric compressor immediately after activation.

Abstract: A rotation angle detector for detecting a relative rotation angle of two respective parts includes two sensors, two magnetic flux induction devices as well as a magnetic flux generation unit. Variation in the magnetic flux formed in respective gaps of the two magnetic flux induction devices is detected by using the two magnetic sensors for detecting a relative rotation angle of the two parts.

Abstract: 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.

Abstract: An N-type epitaxial layer is formed on a p-type silicon substrate. Four N+ regions (diffusion regions used as electrodes) are formed in the N-type epitaxial layer. An insulation layer having a fixed depth is formed around each of the N+ regions on a principal surface of an epitaxial layer. The insulation layer restricts a current path region formed between the N+ regions. Side surfaces of the N+ regions are covered by the insulation layer. The N+ regions are brought into contact with the epitaxial layer by a bottom surface exposed from the insulation layer.

Abstract: 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° 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°.

Abstract: The control device records, in advance, a current data table which specifies relationships between currents in respective phases in a three-phase motor and rotation angles of a rotor of the three-phase motor, obtains, from the current data table, a rotation angle of the rotor of the three-phase motor corresponding to a current in each phase in the three-phase motor detected by a current sensor before driving of the three-phase motor, and obtains an initial position of the rotor.

Abstract: An ultrasonic linear motor according to the present invention has a configuration wherein driving elements are glued at portions on faces of an ultrasonic transducer, facing one another, where rotational directions of elliptic vibrations generated on the faces are reverse one to another, a pair of guides are provided for being pressed into against the driving elements so as to hold the ultrasonic transducer therebetween, and leaf springs serving as pressing part are provided so as to narrow a spacing between the one pair of guides, whereby the ultrasonic transducer is configured as an self-moving ultrasonic linear motor which can drive by itself. Thus, driving properties of the ultrasonic transducer itself is improved, and also the size of the ultrasonic linear motor can be reduced.

Abstract: A magnet is provided to one of two members, which make relative rotation therebetween. First and second Hall elements are arranged adjacent to each other and are provided to the other one of the two members. A magnetic sensing surface of the first Hall element is generally perpendicular to a magnetic sensing surface of the second Hall element, and a relative rotational angle between the two members is determined through the first and second Hall elements based on a magnetic flux, which is generated by a magnetic flux generating portion of the magnet and passes through the first and second Hall elements toward a magnetic flux attracting portion of the magnet.

Abstract: A rotation angle detecting device includes a magnet, a magnetic flux concentrator, a first magnetic sensor, and a second magnetic sensor. The magnet is provided in a rotary member and is substantially coaxially aligned with a rotational axis thereof. The magnet has a magnetic flux generation section and a magnetic flux absorption section oriented in radial directions vertical to the rotational axis. The magnetic flux concentrator is made of a magnetic material and rotates integrally with the magnet. The magnetic flux concentrator is substantially coaxially aligned with the rotational axis and disposed substantially parallel to the magnet. The first and second magnetic sensors are disposed between the magnet and the magnetic flux concentrator at a predetermined angle away from each other in a rotational direction. The rotation angle detecting device detects the rotation angle of the rotary member based on magnetic flux passing through the first and second magnetic sensors.

Abstract: 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.

Abstract: A rotation angle detecting device includes a magnet, a magnetic flux concentrator, a first magnetic sensor, and a second magnetic sensor. The magnet is provided in a rotary member and is substantially coaxially aligned with a rotational axis thereof. The magnet has a magnetic flux generation section and a magnetic flux absorption section oriented in radial directions vertical to the rotational axis. The magnetic flux concentrator is made of a magnetic material and rotates integrally with the magnet. The magnetic flux concentrator is substantially coaxially aligned with the rotational axis and disposed substantially parallel to the magnet. The first and second magnetic sensors are disposed between the magnet and the magnetic flux concentrator at a predetermined angle away from each other in a rotational direction. The rotation angle detecting device detects the rotation angle of the rotary member based on magnetic flux passing through the first and second magnetic sensors.

Abstract: A magnet is provided to one of two members, which make relative rotation therebetween. First and second Hall elements are arranged adjacent to each other and are provided to the other one of the two members. A magnetic sensing surface of the first Hall element is generally perpendicular to a magnetic sensing surface of the second Hall element, and a relative rotational angle between the two members is determined through the first and second Hall elements based on a magnetic flux, which is generated by a magnetic flux generating portion of the magnet and passes through the first and second Hall elements toward a magnetic flux attracting portion of the magnet.

Abstract: A wireless communications terminal stores owner information and function states. A terminal control device transmits, to the wireless communications terminal, control data including control target information for specifying a terminal to be controlled and function state change information indicating a change made in the function states of the terminal. The wireless communications terminal determines, based on the received control target information and the stored owner information, whether or not a function state(s) is to be changed, and changes the stored function states in accordance with the determination result. The wireless communications terminal transmits, to the terminal control device, a process end notification including the terminal's own identification information and indicating whether or not the function state(s) has been changed.