Abstract: An engine combustion condition judging method for detecting a crank angle speed of a multiple cylinder engine, for judging a combustion condition of each of cylinders of the engine based on the detection of the crank angle speed, wherein the improvement includes the steps of setting a predetermined crank angle range selectively determined within a range between a crank angle at which a combustion substantially terminate in a given cylinder and another crank angle at which a combustion substantially start in the next cylinder for detecting a crank angle speed property, and judging the combustion condition based on said crank angle speed property within the predetermined crank angle range. The combustion condition can be obtained reliably so that an appropriate A/F control can be accomplished irrespective of the engine operating condition.

Abstract: An air-fuel control system for an internal combustion engine is equipped with an exhaust system having a catalytic converter, a linear O.sub.2 sensor and a .lambda.O.sub.2 sensor for feedback controlling an air-fuel ratio on the basis of output representative of oxygen content from at least the linear O.sub.2 sensor. The system delivers a target air-fuel ratio of a fuel mixture. A determinant output, based on which the air-fuel ratio is feedback controlled, is shifted from output from the linear O.sub.2 sensor to output from the .lambda.O.sub.2 sensor before the linear O.sub.2 sensor is effectively active.

Abstract: An engine control system in which an air fuel ratio (A/F) is controlled to a lean value closer to a stable combustion limit than a theoretical air fuel ratio under a predetermined operating range, comprising base air fuel ratio control element for setting a target air fuel ratio close to the stable combustion limit and for setting a base air fuel ratio control gain so as to accomplish the target air fuel, a combustion condition judging element for judging a combustion condition of each of cylinders of the engine, air fuel ratio compensating element for compensating the air fuel control gain based on the combustion condition judging element and ignition timing control means for setting an ignition timing in accordance with the target air fuel ratio in the predetermined operating range and for compensating the ignition timing taking account of the compensation of the air fuel ratio by the air fuel ratio compensating element.

Abstract: The method for forming a chemical conversion film on a substrate made of aluminum or its alloy which comprises the steps of: (a) etching a surface of the substrate with an aqueous solution of acid or alkali; (b) immersing the etched substrate in an aqueous, phosphate-based chemical conversion solution which is substantially free from fluoride ions; and (c) applying a negative voltage to the substrate during at least a part of the immersion step so that a potential of the substrate reaches a predetermined minimum potential which is lower than a natural electrode potential of the substrate in the aqueous chemical conversion solution.

Abstract: An intake system for a multi-cylinder internal combustion engine having an intake manifold that is made up of a common intake passage and separate intake passages that branch off from the common intake passage and connect to intake ports of the engine cylinders. An upstream throttle valve is located in the common intake passage. Downstream throttle velves located in the separate branched intake passages near the intake ports. A controller controls intake air actually introduced into the cylinder by actuating the downstream throttle valves to throttle down, smaller than the upstream throttle valve in a light engine load range and by actuating the upstream throttle valve to throttle down smaller than the downstream throttle valves in a heavier engine load range.

Abstract: A dot matrix, fluorescent display tube having a filament, a grid and array of anodes on which light emitters are placed. Two or more light emitters are placed on at least one of the anodes.

Abstract: An engine control system for suppressing vibration of a car body, primarily at acceleration thereof, by varying engine output torque. The system for suppression of the car body vibration takes into consideration car vibration detection delay time created by the intermittent detection of vibration data. The system includes a detector for intermittently detecting data relating to car body vibration, a period setting device for setting a period of car body vibration, a delay time setting device for setting a delay time corresponding to a detection delay time due to the intermittent detection of the vibration data detector, and a torque controller for controlling engine output torque by advancing a phase of engine output torque control timing by the delay time corresponding to the detection delay time, which is set by the delay time setting device, in each period of car body vibration set by the period setting device.

Abstract: An engine fuel supply control system having an air fuel ratio detector which detects the concentration of oxygen content in the engine exhaust gas and providing an air fuel ratio signal representing the air fuel ratio of the engine intake mixture. A control unit is provided to compare the air fuel ratio signal with a reference signal representing a desired air fuel ratio and adjusting the air fuel ratio by a predetermined control factor so that the actual air fuel ratio becomes closer to the desired ratio. The amount of the predetermined control factor is smaller in the engine operating condition wherein the desired air fuel ratio is relatively lean than in the engine operating condition wherein the desired air fuel ratio is relatively rich.

Abstract: An air-fuel ratio control system for an engine in which a fuel injection amount is calculated according to the engine operating conditions and is corrected according to the output of an air-fuel ratio sensor, comprises a base fuel injection amount calculating section for calculating a base fuel injection amount corresponding to the stoichiometric air-fuel ratio on the basis of the intake air amount, a target air-fuel ratio calculating section for calculating a target air-fuel ratio according to the engine operating condition, a reference value calculating section for calculating a reference value which represents the target air-fuel ratio and is submitted to comparison with the output of the air-fuel ratio sensor, a feedback correction coefficient calculating section for calculating a feedback coefficient according to the deviation of the output of the air-fuel ratio sensor from the reference value, and a final fuel injection amount calculating section which corrects the base fuel-injection amount on the basi

Abstract: A music search device for a tape containing a number of pieces of music. If the search begins within a fixed period since the beginning of the currently played piece, the tape jumps back to the beginning of the preceding piece. If the search begins after the fixed period, the tape jumps back to the beginning of the current piece.