Abstract: A coil section includes a primary coil which is magnetically excitable by an AC signal, and secondary coils which are provided so as to generate an inductive output in response to excitation of the primary coil. A self-oscillation circuit, including an inductance element and a capacitor, has incorporated therein the primary coil as the inductance element for self-oscillation. A target section is provided in such a manner that its relative position to the coil section varies according to a position of a target of detection, and the target section includes a magnetically responsive member disposed so that inductance of the secondary coils is varied according to the relative position. Amplitude levels of the output signals of the secondary coils are extracted, and position data of the position of the target of detection is obtained on the basis of these amplitude levels.

Abstract: A detection coil incorporated in a self-oscillation circuit, which includes the coil and a capacitor and is set to a high frequency band (e.g., around 1 MHz or higher). A target section has a relative position to the coil section that varies in response to displacement of a detection object and includes a magnetism-responsive member constructed to cause inductance of the coil to vary with the relative position. A rectifier circuit extracts an amplitude level of an oscillation output signal of the self-oscillation circuit and outputs the extracted level as detected position data. For example, a plurality of self-oscillation circuits are provided. Alternatively, a single self-oscillation circuit forms a plurality of series circuits by, for each coil pair, connecting in series the two coils of the coil pair, and connecting the series circuits in parallel as an inductor element for self-oscillation.

Abstract: A coil section includes a primary coil which is magnetically excitable by an AC signal, and secondary coils which are provided so as to generate an inductive output in response to excitation of the primary coil. A self-oscillation circuit, including an inductance element and a capacitor, has incorporated therein the primary coil as the inductance element for self-oscillation. A target section is provided in such a manner that its relative position to the coil section varies according to a position of a target of detection, and the target section includes a magnetically responsive member disposed so that inductance of the secondary coils is varied according to the relative position. Amplitude levels of the output signals of the secondary coils are extracted, and position data of the position of the target of detection is obtained on the basis of these amplitude levels.

Abstract: A detection coil is incorporated in a self-oscillation circuit. The oscillation frequency of the self-oscillation circuit, which comprises the coil and a capacitor, is set to a high frequency band (e.g., around 1 MHz or higher). A target section whose relative position to the coil section varies in response to displacement of a detection object, and includes a magnetism-responsive member constructed to cause inductance of the coil to vary with the relative position. A rectifier circuit extracts an amplitude level of an oscillation output signal of the self-oscillation circuit and outputs the extracted level as detected position data. For example, a plurality of self-oscillation circuits are provided. Alternatively, a single self-oscillation circuit forms a plurality of series circuits by, for each coil pair, connecting in series the two coils of the coil pair, and includes the result of connecting the series circuits in parallel as an inductor element for self-oscillation.

Abstract: An excitation AC signal biased by a predetermined DC voltage is applied to a coil to allow a DC voltage component in a coil output signal to contain failure information about disconnection, partial disconnection, or the like of the coil. The DC voltage component contained in the coil output signal is detected, and the detected DC voltage is provided as an offset voltage for a failure diagnosis. Further, to check a peak level of the excitation AC voltage, a DC voltage corresponding to the peak level may be contained in the offset voltage. A differential amplifier circuit for obtaining a difference between a coil detection output AC voltage component and a reference AC voltage component outputs an obtained differential signal offset by the offset voltage. Accordingly, the differential signal containing the offset voltage as the failure information is transmitted to a circuit for torque measurement as a torque detection signal via a single output line.

Abstract: An excitation AC signal biased by a predetermined DC voltage is applied to a coil to allow a DC voltage component in a coil output signal to contain failure information about disconnection, partial disconnection, or the like of the coil. The DC voltage component contained in the coil output signal is detected, and the detected DC voltage is provided as an offset voltage for a failure diagnosis. Further, to check a peak level of the excitation AC voltage, a DC voltage corresponding to the peak level may be contained in the offset voltage. A differential amplifier circuit for obtaining a difference between a coil detection output AC voltage component and a reference AC voltage component outputs an obtained differential signal offset by the offset voltage. Accordingly, the differential signal containing the offset voltage as the failure information is transmitted to a circuit for torque measurement as a torque detection signal via a single output line.

Abstract: An electric blower includes an electric motor including a stator and a rotor. The impeller is rotated by the electric motor. An air guide having a plurality of guide blades is disposed around the impeller, and a casing encloses the impeller and the air guide. The casing is provided with a number of exhaust openings through which a part of an air stream suctioned by the impeller is discharged, and a circumferential length of each of the exhaust openings is substantially identical to a circumferential distance between outer peripheral ends of adjacent guide blades. Alternatively, the circumferential length of each of the exhaust openings may be less or greater than the circumferential distance between outer peripheral ends of adjacent guide blades.

Abstract: A vacuum cleaner includes an electric blower for generating a suction air stream and a dust collecting unit for collecting dirt particles contained in the suction air stream. The suction air stream passing through the dust collecting unit into the electric blower flows in an approximately linear path. A dust removing unit is provided for removing dirt particles adhered to the dust collecting unit. The dust removing unit is preferably disposed adjacent to a communication hole between the dust collecting chamber and an electric blower chamber.

Abstract: A vacuum cleaner including an electric blower for generating suction air, a collecting unit for collecting dust contained in the suction air, a dust removing unit for removing dust adhered to the collecting unit, and a dust removing stop unit for stopping an operation of the dust removing unit. The dust removing stop unit stops the operation of the dust removing unit in response to a user's selection or an operation mode of the vacuum cleaner, thereby saving a power consumption of the dust removing unit.

Abstract: Two A.C. output signals amplitude-modulated in accordance with two function values (sine and cosine) differing from each other in correspondence to a position-to-be-detected are received from a position sensor such as a resolver. By performing an addition or subtraction between a signal derived by shifting the electric phase of one of the received A.C. output signals by a predetermined angle, and the other received signal, two electric A.C. signals (sin(?t±d+?), sin((?t±d??)) are electrically synthesized which have electric phase angles (?) corresponding to the position-to-be-detected and are phase-shifted in opposite directions. “±d” here represents phase variation error caused by factors, other than the position-to-be-detected, such as temperature change. In the synthesized two signals, the phase variation errors (±d) appear in the same direction, while the phase differences (?) corresponding to the position are shifted in opposite, positive and negative, directions.

Abstract: A vacuum cleaner includes an electric blower for generating a suction air stream and a dust collecting unit for collecting dirt particles contained in the suction air stream. The suction air stream passing through the dust collecting unit into the electric blower flows in an approximately linear path. A dust removing unit is provided for removing dirt particles adhered to the dust collecting unit. The dust removing unit is preferably disposed adjacent to a communication hole between the dust collecting chamber and an electric blower chamber.

Abstract: In a control unit for use with a power steering apparatus, there are provided and integrated into a single body, a main operating fluid feed device for supplying the hydraulic cylinder with an amount of oil corresponding to the amount of rotation of the steering wheel H, an auxiliary operating fluid feed device for supplying a correcting oil for adjusting drive of said hydraulic cylinder according to control signal, and a steering wheel angle sensor disposed around the rotating shaft of the steering wheel connected to said main operating fluid feed device, to detect steering wheel angle corresponding to the rotating position of said steering wheel.

Abstract: An electric blower includes an electric motor including a stator and a rotor. The impeller is rotated by the electric motor. An air guide having a plurality of guide blades is disposed around the impeller, and a casing encloses the impeller and the air guide. The casing is provided with a number of exhaust openings through which a part of an air stream suctioned by the impeller is discharged, and a circumferential length of each of the exhaust openings is substantially identical to a circumferential distance between outer peripheral ends of adjacent guide blades. Alternatively, the circumferential length of each of the exhaust openings may be less or greater than the circumferential distance between outer peripheral ends of adjacent guide blades.

Abstract: A vacuum cleaner including an electric blower for generating suction air, a collecting unit for collecting dust contained in the suction air, a dust removing unit for removing dust adhered to the collecting unit, and a dust removing stop unit for stopping an operation of the dust removing unit. The dust removing stop unit stops the operation of the dust removing unit in response to a user's selection or an operation mode of the vacuum cleaner, thereby saving a power consumption of the dust removing unit.

Abstract: In a control unit for use with a power steering apparatus, there are provided and integrated into a single body, a main operating fluid feed device for supplying the hydraulic cylinder with an amount of oil corresponding to the amount of rotation of the steering wheel H, an auxiliary operating fluid feed device for supplying a correcting oil for adjusting drive of said hydraulic cylinder according to control signal, and a steering wheel angle sensor disposed around the rotating shaft of the steering wheel connected to said main operating fluid feed device, to detect steering wheel angle corresponding to the rotating position of said steering wheel.

Abstract: Two A.C. output signals amplitude-modulated in accordance with two function values (sine and cosine) differing from each other in correspondence to a position-to-be-detected are received from a position sensor such as a resolver. By performing an addition or subtraction between a signal derived by shifting the electric phase of one of the received A.C. output signals by a predetermined angle, and the other received signal, two electric A.C. signals (sin(&ohgr;t±d+&thgr;), sin((&ohgr;t±d−&thgr;)) are electrically synthesized which have electric phase angles (&thgr;) corresponding to the position-to-be-detected and are phase-shifted in opposite directions. “±d” here represents phase variation error caused by factors, other than the position-to-be-detected, such as temperature change.

Abstract: Two A.C. output signals amplitude-modulated in accordance with two function values (sine and cosine) differing from each other in correspondence to a position-to-be-detected are received from a position sensor such as a resolver. By performing an addition or subtraction between a signal derived by shifting the electric phase of one of the received A.C. output signals by a predetermined angle, and the other received signal, two electric A.C. signals (sin(&ohgr;t±d+&thgr;), sin(&ohgr;t±d−&thgr;)) are electrically synthesized which have electric phase angles (&thgr;) corresponding to the position-to-be-detected and are phase-shifted in opposite directions. “±d” here represents phase variation error caused by factors, other than the position-to-be-detected, such as temperature change.

Abstract: A winding section includes a primary winding to be excited by a single-phase A.C. signal, and a plurality of secondary windings provided at different locations with respect to a predetermined direction of linear movement. A variable magnetic coupling section includes a plurality of magnetic response members provided in repetition at a predetermined pitch along the direction of linear movement, and allows inductive A.C. output signals, amplitude-modulated in accordance with a varying linear position of an object of detection, to be produced in the individual secondary windings with amplitude function characteristics differing depending on positional differences between the secondary windings. Each of the inductive A.C. output signals produced in the secondary windings varies in its amplitude function in periodic cycles each corresponding to the pitch length of the magnetic response members.

Abstract: A group of secondary windings are distributively provided on a stator over a predetermined range, and the respective inductance of the secondary windings in the group is set in such a manner to present predetermined inductance distribution. A rotor has an eccentric shape so as to cause variations in magnetic coupling at individual poles of the stator in response to its current rotational position. By combined use of the magnetic coupling variations between primary and secondary windings on the stator and the predetermined inductance distribution of the secondary windings, high-accuracy detection of a rotational position is achieved with a simple structure. A plurality of primary windings may be set so as to present predetermined inductance distribution.

Abstract: Two A.C. output signals amplitude-modulated in accordance with two function values (sine and cosine) differing from each other in correspondence to a position-to-be-detected are received from a position sensor such as a resolver. By performing an addition or subtraction between a signal derived by shifting the electric phase of one of the received A.C. output signals by a predetermined angle, and the other received signal, two electric A.C. signals (sin(.omega.t .+-.d.+-..theta.), sin(.omega.t.+-.d-.theta.)) are electrically synthesized which have electric phase angles (.theta.) corresponding to the position-to-be-detected and are phase-shifted in opposite directions. ".+-.d" here represents phase variation error caused by factors, other than the position-to-be-detected, such as temperature change. In the synthesized two signals, the phase variation errors (.+-.d) appear in the same direction, while the phase differences (.theta.