Denso Corporation

Nippondenso Co., Ltd.

Jeco Co., Ltd.

Seiichirou Ootake

Masato Ishihara

Masahiro Aratani

Yukihiko Tanizawa

Kazuyoshi Nagase

Takeshi Tsukamoto

Takashige Saitou

Makoto Hatanaka

Yasuhiro Yamashita

Norio Miyahara

Shinji Ozaki

Takeshi Otsuka

Kazuhiro Chiku

Takeshi Tukamoto

Toru Iwasa

A current sensor for measuring an electric current flowing through a conductor includes a ring shaped magnetic core, a bare semiconductor chip, and a case. The magnetic core has a gap and surrounds the conductor. The bare semiconductor chip has a front surface and a vertical Hall effect element formed on the front surface. The bare semiconductor chip is arranged in the gap of the magnetic core to detect a magnetic field generated by the electric current. The magnetic core and the bare semiconductor chip are accommodated in the case. A back surface of the bare semiconductor chip is fixed in the case in such a manner that the front surface of the bare semiconductor chip is parallel to a direction of the magnetic field.

Current sensor

A magnetic core is shaped in a ring having a gap and disposed to surround a conductive wire. When an electric current flows in the conductive wire, a magnetic field is generated in the gap. A sensor package includes a Hall element and a lead frame, which are embedded in a resin mold. The sensor package is disposed in the gap to produce an output signal corresponding to the magnetic field in the gap. The Hall element is positioned in the center of the gap, that is, at the position which is the same distance from the end surfaces of the magnetic core.

Current sensing device

A current detection apparatus includes a magnetic core having a ring shape with a gap and a center opening portion through which a current path is disposed, and a magnetic sensor including a magnetic sensing element such as a Hall effect element arranged in the gap. When a current flows through the current path, the magnetic core generates magnetic flux therein so that magnetic field is generated in the gap. The magnetic sensor outputs different electrical signals, each of which is measured in a different measurement range and corresponds to intensity of the magnetic field in the gap. The current detection apparatus measures the current based on the electrical signals outputted from the magnetic sensor.

Current detection apparatus

A pressure sensor includes a casing having a pressure detection chamber, a diaphragm for receiving pressure of a measuring object and disposed on the casing, and a pressure detection element. The pressure detection chamber is filled with a liquid, and the diaphragm contacts the liquid. The pressure detection element is disposed in the pressure detection chamber to receive the pressure of the liquid. The diaphragm has a plate shape with a radius of R and includes a circumference and a center of the plate. The circumference is fixed to the casing. The diaphragm further includes a corrugate disposed concentrically with the center of the diaphragm and having a half circular cross-section and a top of the half circle. The top of the corrugate is disposed within a distance of 0.6 R from the center of the diaphragm.

Pressure sensor

A pressure detecting apparatus is composed of a first case insert-molded with connector pins, and a second case made of metal. The first case and the second case are assembled together to form a pressure detection chamber hermetically sealed with an O-shaped ring sandwiched between seal surfaces of the two cases. The first case is formed by using a molding die that has a gate for injecting resin approximately in parallel with a seal correspondence surface for forming the seal surface of the first case.

Method for manufacturing hermetically sealed pressure detecting apparatus

A brake hydraulic pressure detector includes a bridge circuit made up of a semiconductor sensor which generates a detection voltage in accordance with hydraulic pressure and resistors for setting the detection voltage during nonbraking to a nonzero predetermined voltage, an adder circuit for amplifying and generating the detection voltage from the bridge circuit by a predetermined gain, and an output circuit. Here, if the sensitivity of an output voltage with respect to the hydraulic pressure varies, i.e., if the gain varies for some reason, the output voltage during nonbraking also changes because the offset voltage is set to a nonzero voltage. Thus, abnormality in the sensitivity of the brake hydraulic pressure detector can be detected by monitoring the output voltage during nonbraking.

Sensor device with a self adjustor for eliminating abnormal sensitivity

A diaphragm portion 20 causes deflection, when high-temperature fluid pressure acts on the pressure sensing surface A of the diaphragm portion 20. This deflection is transmitted via pressure transmitting members 7, 8 to a deflection sensing member 6 which generates an electric signal in response to a pressure received. The diaphragm portion 20 has a recess portion 21 at its center. The recess portion 21 is symmetrical about a central axis of the diaphragm portion 20. A tip end of the pressure transmitting member 7 is brought into contact with the recess portion 21 at a central point. A tapered portion 2d of the diaphragm 20 has a thickness of t.sub.3 which is not larger than the thickness t.sub.1 of an outer peripheral portion 2b or t.sub.2 of a central bottom portion 2c. Furthermore, a heat insulating plate can be provided on the diaphragm to protect the surface A of the diaphragm portion from heat radiation of high-temperature fluid.

Growing community of inventors

Hazu-gun, Japan

Seiichirou Ootake