Abstract: A crash detection apparatus of an air bag system comprises a detection unit for detecting acceleration caused therein by an automobile and outputting electric signals corresponding to the acceleration, a discrimination unit for discriminating, from the signals from the detection unit, a crash signal which is outputted on the basis of the acceleration caused by crash of the automobile, the crash signal being inputted into an inflator to inflate an air bag. The detection unit is a capacitance type semiconductor detector comprising a pair of fixed electrodes and a cantilevered movable electrode disposed between the fixed electrodes and fixed at an end thereof, and a servo control unit is electrically connected to the detection unit so as to form a negative feedback loop, of a detection signal.

Abstract: An accelerometer having a movable electrode which is moved according to acceleration with respect to a fixed electrode disposed in opposition to the movable electrode. An output device generates an output voltage which is proportional to the acceleration by measuring a gap between the movable electrode and the fixed electrode. A pulse width modulator generates pulses, wherein a pulse width of the pulses is modulated according to the output voltage, and a feedback device feeds back an electrostatic force which is proportional to the pulse width of the pulses from the pulse modulator between the movable electrode and the fixed electrode. As the acceleration in the acceleration sensor is linearly detected, the acceleration sensor is easily adjusted.

Abstract: Light equipment is provided for irradiating the measuring object and forming light spot on it through the collimate lens. Reflected light from the measuring object is incident to the spatial filter through the objective lens for detecting the incidence position of the reflected light. A distance measuring circuit calculates contiuously the distance (d) between the objective lens and the measuring object by optical triangulation based on the output signal from the spatial filter. The frequency detecting circuit is connected to the spatial filter. When the sought running speed is V, the pitch between each equivalent light receiving element p, and the magnification of the optical image of the measuring object M, the frequency detecting circuit measures the frequency f which is given by the formula of F=MV/p. The calculator calculates the velocity V based on the output signal from the distance measuring circuit and on the output signal from the frequency detecting circuit.

Abstract: A switch element (SW.sub.1) is connected in series between an air-fuel ratio detecting cell (1) and a power source (Vo) and controlled by a control time generator (4). A potential ground (V.sub.PG) is connected to a cathode side of the detecting cell (1). An output voltage from the detecting cell (1) is input into a sample hold circuit (SW.sub.2, C.sub.1, A.sub.2) which is controlled by a control time generator (4) adapted to control the switching element (SW.sub.1) and sample hold circuit alternately. An output from the sample hold circuit is compared with an electromotive force control value (e) in a comparator circuit (A.sub.1), and output as an oxygen concentration-detected signal. A temperature setting resistor (r.sub.2) and a load resistor (R.sub.2) are connected between an output terminal of the sample hold circuit and the switching element (SW.sub.1). The voltage (e.sup.+, e.sup.-) from a node of the detecting cell (1) and an electric current detecting resistor (R.sub.

Abstract: A method for manufacturing semiconductor absolute pressure sensor units includes anodically bonding a silicon sensor wafer (10) and a silicon cap wafer (12) with a borosilicate glass layer (32) disposed therebetween so as to surround respective sensor chips on the silicon sensor wafer (10) by introducing a matrix shaped conductive layer (28) in contact with and in alignment with the borosilicate glass layer (32), the matrix shaped conductive layer (28) is used as a negative electrode during anodic bonding operation so that a high bonding strength is obtained and sodium ions contained in the borosilicate glass layer (32) are kept away from bond regions after completing the anodically bonding operation.

Abstract: A semiconductor pressure transducer including a measuring diaphragm of semiconductor material for sensing pressure supported by a support member of the same material. An oxide layer and a thin glass layer are interposed between the measuring diaphragm and the support member.

Abstract: An air-fuel ratio controlling apparatus for internal combustion engines including an oxygen sensor of hermetic type is disclosed. A pump cell of the oxygen sensor is connected with a power supply through a switch circuit for switching the direction of current flow. A control unit computes a setting of oxygen concentration of a reference gas layer of an exhaust gas sensor in accordance with the operating parameters. By a setting interruption, the control unit switches the switch circuit toward exhausting direction, drives the power supply and applies the exhaust current to the pump cell. The completion of exhaustion is detected, the switch circuit is switched to the suction, and the power supply is driven to apply the suction current to the pump cell. The setting is compared with the integration value of the suction current by a comparator circuit, or the suction current is fixed to control the drive time of the power supply.

Abstract: A capacitive pressure sensor and its manufacturing method are disclosed. An amplifier is formed on the main surface of a first semiconductor substrate by a diffusion process, and its surface is covered with an insulating film. An electrode is vapor-deposited on the surface of the amplifier and electrically connected to the amplifier through a through hole formed in the insulating film. For forming a diaphragm, the surface of a second semiconductor substrate disposed facing the electrode to form a capacitor, which is opposite to the surface of the second semiconductor substrate facing the electrode, is partially etched away to form a depression. The first and second semiconductor substrates are anodically bonded to each other using a glass layer.

Abstract: Four semiconductor strain gauges constitute a bridge circuit. This bridge circuit and a sensitivity temperature compensation circuit are connected in series, and a constant voltage is applied to the series circuit. The sensitivity temperature compensation circuit varies a voltage across the bridge circuit, depending upon temperatures. The constant voltage is divided to produce a predetermined voltage. The predetermined voltage is selected to be equal to the voltage of one output side node of the bridge circuit at the time when the semiconductor strain gauges are unstrained and at a predetermined temperature. The point of this voltage and the output side node are connected through a resistor so as to perform zero-point temperature compensation.

Abstract: A semiconductor pressure sensor having plural pressure sensitive diaphragms and capable of producing electric signals of at least two pressures.A semiconductor pressure sensor has a semiconductor single crystal chip (1) on which two diaphragms (12a, 12b) are shaped, pairs of strain gauges (13a and 14a, and 13b and 14b), each of which pairs are constructed on each pressure sensitive diaphragm, electrodes (15a and 16a, and 15b and 16b) which are provided for electrical connections of these strain gauges on the semiconductor single crystal, and an insulating substrate of borosilicate glass, the thermal expansion coefficient is substantially equal tol that of said semiconductor single-crystal chip, wherein the semiconductor single-crystal chip (1) and the glass substrate (2) are bonded to each other by an Anodic Bonding method, thereby being able to obtain a semiconductor pressure sensor which scarcely producing errors outputs.