Abstract: A gas composition sensor for sensing the air-fuel ratio of the exhaust gases from an automobile. The gas composition sensor includes a gas composition sensing element composed of a sintered metal oxide having an electric resistance value varying in accordance with the composition of gases to be sensed, and at least one reticulated metal plate is disposed inside or on the surface of the gas composition sensing element.

Abstract: An apparatus for detecting a deteriorated condition of an oxygen concentration sensor mounted in an exhaust pipe for an internal combustion engine for controlling an air-fuel ratio is described. The apparatus includes, in addition to the sensor, a reference oxygen concentration sensor mounted in the exhaust pipe downstream of a cleaning device, and a discrimination unit for determining the deterioration of the oxygen concentration sensor for controlling the air-fuel ratio by measuring at least one of a duty factor and a period of an output signal from the reference oxygen concentration sensor.

Abstract: An additional air supply control apparatus for an internal combustion engine including a bypass passage for supplying air additionally to the engine and a control valve provided in the bypass passage for controlling the amount of air-flow through the bypass passage. A gas sensor is mounted in an exhaust system of the engine for detecting changes in the air-fuel ratio and a control unit produces an intermittent control signal in accordance with a detection signal from the gas sensor. The control valve is driven by the control signal intermittently in a skip movement fashion.

Abstract: An ignition system for internal combustion engines wherein an ignition timing computer circuit starts the computation of an ignition timing in response to the detection of a predetermined angular position of the crankshaft of an internal combustion engine by an angular position detector, and an ignition device ignites the engine according to the computed ignition timing. A pressure detector detects variations of the pressure in the cylinders caused by the ignition of the engine and a retard-advance detector determines whether the angular position of the engine crankshaft corresponding to the maximum cylinder pressure agrees with the desired angular position. This retard-advance detector compensates the computation of ignition timing in the ignition timing computer circuit in accordance with its determination.

Abstract: In a gas component sensing apparatus a pair of thin film electrodes are arranged on opposite sides of a gas component sensor element, an electrical resistance of which varies in accordance with gas component in a gas under test. The change in the electrical resistance is taken out between a lead member and a housing through a first electrically conductive path which electrically connects one of the pair of electrodes to the lead member and a second electrically conductive path which electrically connects the other electrode to the housing.

Abstract: A deteriorated condition detecting apparatus for an oxygen concentration sensor used in an air-fuel ratio feedback control for an internal combustion engine comprises a reference oxygen concentration sensor mounted in proximity to the oxygen concentration sensor used for the air-fuel ratio feedback control and a discriminator for comparing duty factors of output signals from those two sensors to determine a deteriorated condition of the oxygen sensor. The discriminator determines the deteriorated condition when the duty factor of the sensor under test deviates from the duty factor of the output signal of the reference sensor by a predetermined amount.

Abstract: An air-fuel ratio adjusting apparatus for an internal combustion engine employing a gas sensor whose electric characteristic changes rapidly at near the stoichiometric air-fuel ratio so as to maintain the air-fuel ratio of mixture at any desired air-fuel ratio other than the stoichiometric one. A bypass valve is mounted in a bypass passage for supplying additional air to the portion of the carburetor downstream of its throttle valve. In response to the sensed signal from the gas sensor mounted in the exhaust pipe, the bypass valve is opened or closed to increase or decrease the amount of additional air.

Abstract: A current detecting apparatus wherein when a wire is energized, a reed switch comes into operation in response to the magnetic lines of force generated concentrically around the wire to detect the presence of a current flow in the wire. The current detecting apparatus may be easily attached on and removed from a wire.

Abstract: An additional air control device for an internal combustion engine wherein an additional air supply to the engine is controlled by controlling the operation of a drive motor coupled to a control valve mounted in a bypass passage. The driving direction of the drive motor to open or close the control valve is controlled by a gas sensing signal representing the content of the exhaust gas and generated by a gas sensor, and the duty ratio between the drive time period .tau.a and the rest time period .tau.b of the drive motor is controlled depending on an intake air flow signal representing a delay time factor from an intake air flow meter. In deceleration operation of the engine, the duty ratio .tau.a/.tau.b is increased independently of the intake air flow signal by a deceleration signal produced by a deceleration detecting switch. The drive motor is thus controlled to drive in a skip movement fashion and to stop alternately with the duty ratio of .tau.a/.tau.

Abstract: In an air-fuel ratio controlling device which comprises an exhaust gas sensor for detecting the air-fuel ratio of mixture and an additional air passage including a bypass valve and disposed to supply additional air to the downstream side of the throttle valve of an engine, the controlling device further comprises a throttle sensor operatively connected to the throttle valve for producing an output signal corresponding to the opening of the throttle valve, and a control circuit responsive to the signal from the throttle sensor whereby a predetermined time period after the occurrence of a change in the opening of the throttle valve is discriminated as the acceleration or deceleration period of the engine and the bypass valve is driven at one or the other of two speed depending on whether the engine is in the accleration/deceleration operating condition or other operating conditions.

Abstract: An additional air control device for maintaining constant air-fuel ratio in an internal combustion engine wherein an intake air which is supplied additionally through a bypass passage to the engine is controlled by controlling the movement of a drive motor coupled to a control valve mounted in the bypass passage. A gas sensor for sensing the oxygen content of the exhaust gas and an intake air flow meter for sensing the rate of intake air flow to the engine are provided.

Abstract: In controlling an amount of intake air of an internal combustion engine, an error due to the delay time between the time at which the air-fuel ratio changes in the intake system of the engine and the time at which a gas sensor in the exhaust system of the engine senses the changes is compensated. At least two delay factor detectors, e.g., an engine speed sensor and a pressure sensor control the driving and stopping of a drive motor coupled to a control valve mounted in the additional air passage in the intake system to thereby adjust the amount of additional air supply.

Abstract: A combination meter for an automobile comprising a first group of indicators and a second group of indicators adapted to come into operation later than the first group of indicators by a predetermined time, whereby when a key switch is closed by the driver of an automobile, those items which are essential in the safe driving of the automobile are sequentially indicated thus enabling the driver to check each of these essential items.

Abstract: There is provided a received signal frequency indicating system for indicating a frequency of a signal received by a heterodyne type receiver, and, when a local oscillator signal of the receiver and a d.c. voltage are transmitted through a coaxial cable to a remote place, the received signal frequency is indicated there in a digital form.

Abstract: A device for detecting the specific gravity and level of liquid in a container comprising a light source, a photoelectric transducer positioned in light receiving relationship with respect to the light source, a float which has a predetermined specific gravity and is displaced depending upon the change in specific gravity and level of the liquid, and means operatively coupled to the float so as to permit or interrupt the light transmission from the light source to the photoelectric transducer.

Abstract: There is provided a digital acceleration detecting system for rotating bodies comprising a first counter for counting the number of pulse signals corresponding to the rotational speed of a rotating body, a second counter for counting the number of the pulse signals later than the first counter, and a control circuit for generating an output signal corresponding to the difference between the counts of the first and second counters.