Mitsubishi Electric Corporation

Hirai Engineering Corporation

Mitsubishi Denki Kabushiki Kaisha

Kabushiki Kaisha Hirai Giken

Satake Corporation

Showa Aluminium K.k.

Takashi Hirai

Hiroyuki Tsutada

Haruhiko Kohyama

Keisuke Hirai

Kenji Kamei

Kenji Inomata

Yoshio Kaneko

Satoru Inoue

Satoru Satake

Hajime Nakajima

Hiroki Ito

Takeshi Musha

Yoshinao Tatei

Kazuto Nonaka

Takuya Noguchi

Yuji Hase

Noriyuki Miyake

Takashi Sesekura

Takashi Shindoi

Tadahiro Hino

Kenji Morita

Takuma Nakaso

Syuji Aizawa

An optical encoder includes: an optical scale having periodical optical patterns and can be relatively and angularly displaced; a projector for irradiating the optical scale with light; a light receiver for receiving light from the optical scale; and a calculator for calculating an absolute rotation angle &#x3b8; of the optical scale in accordance with a signal from the light receiver. The optical patterns include a plurality of light shielding portions and a plurality of light transmitting portions, each of the portions being located alternately. When a pitch of an n-th light shielding portion in a predetermined circumferential direction is denoted by Pn and a width of the n-th light shielding portion is denoted by Wn, a transmissivity T(&#x3b8;n) corresponding to an angle &#x3b8;n of the n-th light shielding portion and the pitch Pn of the light shielding portion satisfy predetermined equations, and the width Wn of the light shielding portion in the optical pattern varies in accordance with a function of the pitch Pn of the light shielding portion.

Optical encoder

A target closing phase determining circuit determines energization flux errors in respective phases and respective closing phases of a first phase, and determines a target closing phase of the first phase so as to minimize an evaluated value related to determined energization flux errors in the respective phases. Each of the energization flux errors is the maximum value of absolute values of center values of transformer fluxes generated in a static state after energization. The target closing phase determining circuit determines the energization flux errors based on residual flux values for the first to third phases of a three-phase power supply, respectively, a pre-arc characteristic and a closing time variation characteristic of a three-phase circuit breaker, a connection condition of windings of a three-phase transformer, to which the three-phase circuit breaker is connected, and voltage phase differences among the phases of the three-phase power supply.

Transformer inrush current suppression apparatus with function of determining target closing phase of three-phase transformer based on pre-arc characteristic and variation in closing time of the three-phase circuit breaker

A residual magnetic flux measurement apparatus measures residual magnetic fluxes by using a transformer-voltage measurement means for measuring transformer voltages; a voltage delay means for delaying the measured signals; a DC-voltage-component calculation means for calculating DC voltage components from the latest transformer-voltage signals for a predetermined time period based on calculation-control signals; a voltage integration means for calculating voltage-integration signals by performing voltage integration of signals obtained after separating the DC voltage components from present transformer-voltage signals; a magnetic-flux DC-component calculation means for calculating magnetic-flux DC-components from the latest voltage-integration signals for a predetermined time period based on the calculation-control signals; a magnetic flux calculation means for obtaining magnetic flux signals in which the magnetic-flux DC-components are separated from present voltage-integration signals; and a control means for obtaining residual magnetic fluxes based on contact signals, an interruption mode, the transformer-voltage signals, and the magnetic flux signals.

Residual magnetic flux determining apparatus

A method determining a malfunction when a reception signal fluctuates at a receiver owing to malfunctions occurring on a leaky cable and its related devices. The method determines, among range bins correlating the reception signal with a distance from a feed end of a radio-wave radiation unit and a radio-wave reception unit, based on a correlation between a time-delay from a transmission time of a transmission signal until a reception time of the reception signal and a transmission path distance of the reception signal in the radio-wave radiation unit and the radio-wave reception unit, when, comparing the reception signal with the transmission signal with respect to the range bin corresponding to a far end, a level of amplitude reduction in the reception signal exceeds a predetermined ratio, that a malfunction is present in either the radio-wave radiation unit or radio-wave reception unit.

Intrusion-object detection system, method of detecting intrusion-object and method of detecting malfunction

A target-closing phase-map generating section generates in advance a target closing phase map in consideration of a pre-arc characteristic and variations of a mechanical action of a breaker, and amplitude fluctuations of the load voltage. A target-closing time calculating section calculates a target closing time string from frequencies and phases of the power source voltage and the load voltage, respectively, of the breaker referring to the target closing phase map. A closing control section, when a close commandis inputted, controls the timing of outputting a closing control signal based on a predicted closing time and the target closing time string.

Controlled switching device

A leaky cable having radiation directivity which varies with frequency transmits electric waves in different frequency bands. A measurement apparatus outputs measurement information including signal intensity and phase of a reflected electric wave in each frequency band which is reflected by a target and is received by another leaky cable, and propagation delay time. A calculator groups the measurement information by target on the basis of signal intensities and phases of the reflected electric waves in different frequency bands, and calculates the position of the target with respect to the longitudinal direction of the leaky cables and the distance between the target and the leaky cables.

Approach detecting system

A closing phase that produces the smallest energization flux error at a connection input point is calculated based upon a residual flux of the first closing phase and the preliminarily given pre-arc characteristic and closing time deviation characteristic of a three-phase circuit breaker, so that the calculated phase value is set as a target closing phase of the first closing phase. A closing phase that produces the smallest energization flux error when a residual flux of zero is calculated, so that the calculated phase value is set as a target closing phase of the remaining two phases. The total time required from the reference point to the target closing phases of the remaining two phases and a delay time corresponding to an integer multiple of a given cycle of the three-phase power supply is set as a target closing time of the remaining two phases.

Transformer inrush current elimination system

Rice cleaning machine

A close control signal or an open control signal is outputted after a wait time of a half cycle or less upon a close command or an open command to a breaker in order to make a breaker at a predetermined interpole voltage phase or to open a main circuit current at a predetermined phase. When the close command or the open command is detected, a delay time is determined based on latest zero point time and a predicted close time or a predicted open time, and the close control signal or the open control signal is outputted after a lapse of the delay time so as to make or to open a pole at the predetermined phase of the interpole voltage or the main circuit current.

There is provided at least one pressure detector for detecting a change in pressure of an insulating medium, a vibration detector for detecting vibration of an oil-filled electric equipment, and a determination processor for determining, based on information detected by the pressure detector and the vibration detector, whether an internal short circuit has occurred in the oil-filled electrical equipment.

Supervisory apparatus for oil-filled electrical equipment

A roof system utilizing a solar cell comprising a first modular roof member composed of a plurality of first light collecting plate segments each of which having a solar cell embedded therein, the first light collecting plate segments being aligned in one direction and in the other direction perpendicular to the one direction; and a second modular roof member composed of a plurality of second light collecting plate segments each of which is equal in size to the first light collecting plate segment, the second light collecting plate segments being aligned in one direction and in the other direction perpendicular to the one direction, the number of the second light collecting plate segments in one direction being larger by one than that of the first light collecting plate segments.

Roof system utilizing a solar cell

A roof mounted light transmitting frame has a pair of longitudinal sash members. A light-transmitting sheet support sash member is mounted obliquely along the inner surface of each longitudinal sash member such that the distance between its front end and the lower edge of the longitudinal sash member is larger than the distance between its rear end and the lower edge of the longitudinal sash member. A lower horizontal sash member with a vertical support member is mounted between front ends of the light-transmitting sheet support sash members. An upper horizontal sash member is mounted between rear ends of the light-transmitting sheet support sash members. A light-transmitting sheet is mounted between the light-transmitting sheet support sash members, and the upper and lower horizontal sash members. A recess is longitudinally formed on the lower horizontal sash member to receive an upper horizontal sash member of the next frame.

Roof mounted light transmitting frame

Roof

A roof apparatus includes a plurality of light collecting members, each having a pair of left and right vertical members, an upper horizontal member, a lower horizontal member, and a transparent plate. The upper horizontal members are disposed at a ridge side end of the vertical members, the lower horizontal members are disposed at an eaves side end of the vertical members, and the transparent plate is disposed on the inner periphery of the vertical members, the upper horizontal member, and the lower horizontal member. The light collecting members are connected in a slope direction of the roof, and the lower horizontal member has a transparent plate holding piece, a transparent plate contact wall, and a cover piece. The transparent plate holding piece is adapted to hold an eaves side end of the transparent plate. The transparent plate contact wall has a thickness which is smaller than the thickness of the transparent plate. The cover piece is adapted to cover an upper portion of the upper horizontal member of an adjacent eaves side light collecting member and extends from the upper end of the transparent plate contact wall.

Growing community of inventors

Tokyo, Japan

Takashi Hirai