Abstract: A novel method of controlling air-fuel ratio for an internal combustion engine is disclosed, which comprises a memory area for holding regional compensation factors used for air-fuel ratio control, a memory area for holding new regional compensation factors obtained by learning, and a memory area for holding regional compensation factors based on the result of the learning immediately before the latest learning, thus rationalizing the new setting and updating processes of regional compensation factors according to the result of learning.

Abstract: An A/F sensor for an automobile comprises means for providing an electrical potential higher than ground on the sensing electrode such that the sensor is able to detect air-fuel ratios over the entire spectrum of such ratios from lean through rich.

Abstract: A method for controlling an engine includes the steps of sampling instantaneous flow rates of intake air supplied to the engine, computing the quantity of intake air to be supplied to the engine in an intake stroke on the basis of the sampled instantaneous intake air flow rates, computing the quantity of injected fuel in the intake stroke on the basis of the computed intake air quantity, and injecting the computed quantity of fuel to the engine. In the method, the step of computing the injected fuel quantity includes the step of computing the ratio between the instantaneous intake air flow rate sampled at a reference timing in the preceding intake stroke and that sampled at reference timing in the present intake stroke for correcting the quantity of intake air supplied in the present intake stroke.

Abstract: A semiconductor-type pressure transducer is disclosed in which the pressure change is detected as a resistance change by use of a bridge circuit including at least a gauge resistor changing with an external force. Each gauge resistor is made of a PN junction of a semiconductor. The pressure transducer further comprises an amplification factor compensator for cancelling the effect of the temperature change of the gauge resistors making up the bridge circuit on the amplification factor of the amplification circuit for amplifying the output of the bridge circuit.

Abstract: A switching device and circuit comprises a bipolar transistor and at least two field effect transistors for controlling the bipolar transistor. A first field effect transistor has its drain and source connected across the collector-base of the bipolar transistor and a second field effect transistor has its drain and source connected across the base-emitter of the bipolar transistor. Gates of the first and second field effect transistors are connected in common and supplied with a voltage signal. The first field effect transistor is of an enhancement type and the second field effect transistor is of a depletion type.

Abstract: A semiconductor switching device is disclosed in which a bipolar transistor has a plurality of emitter electrodes and in which each of said emitter electrodes is connected to one of a plurality of MOS transistors (so that the number of MOS transistors corresponds to the number of emitter electrodes of the bipolar transistor). The drains of the MOS transistors are connected in common, and the gate electrode and source electrode of each MOS transistor are each connected in common to the gate electrodes and source electrodes of the other MOS transistors.

Abstract: In an electronic control apparatus for an internal combustion engine, the contents of a selected reference register are compared with the count contents of a timer so that when equality is found therebetween, an interrupt signal is applied to a central processing unit, which then computes when and how a control condition is to be changed with respect to one of a plurality of controlled systems and the contents of the reference register are updated accordingly. In addition, a plurality of actuators for controlling the operation of the engine are selectively controlled in accordance with control signals generated from the central processing unit on the basis of the receipt of the interrupt signals.

Abstract: A pressure transducer comprises a pressure sensor including a bridge connection of gauging resistors formed on a semiconductor substrate, and a power supply connected to the pressure sensor for driving it and basically acting as a constant current source. The power supply includes at least two transistors formed on the semiconductor substrate. One of the transistors provides a collector current which is less in temperature-dependency relative to that of the other transistor, and the other transistor has a collector circuit connected to the pressure sensor and provides a collector current corresponding to a sum of a substantially temperature-dependent current and a substantially temperature-independent current.

Abstract: A pressure transducer is disclosed comprising a pressure sensor portion having gage resistors in bridge formed on a thin diaphragm of a semiconductor substrate, and a power supply connected to the pressure sensor portion for driving the pressure sensor. The power supply includes a first current source for supplying a temperature-dependent current equivalent to the sum of a current almost proportional to the absolute temperature and a current independent of temperature, and a second current source for sinking the current almost proportional to the temperature characteristic of the gage resistors from the current of the first current source.

Abstract: A method of controlling an internal combustion engine employs a microcomputer to control the fuel supply to the engine as well as the ignition timing thereof on the basis of measurement of the air quantity fed to the engine. For measuring the air quantity charged to the engine with high accuracy, the intake air flow fed to the engine is sampled in synchronism with the pulsating variation thereof. A value obtained by averaging the sampled values is used as the intake air quantity on the basis of which the fuel supply and the ignition timing are arithmetically determined.

Abstract: A method of controlling fuel supplied to an engine comprises the steps of computing the quantity of air taken into the engine on the basis of the output from an air flow rate sensor, integrating the quantity of intake air computed in the first step, determining the level for setting the period of generation of a fuel-quantity control pulse signal from a pulse generating circuit on the basis of the output from an exhaust gas sensor, and generating pulses of predetermined pulse width from the pulse generating circuit when a predetermined relation is attained between the level determined in the third step and the result of integration in the second step.

Abstract: An air flow rate measuring apparatus in which an air flow sensor whose electric characteristic varies with the rate of air flowing by the sensor is supported on a heat-insulating support member and located in a bypass tube provided in the vicinity of the main venturi of an internal combustion engine, whereby the air flow sensor is isolated from adverse thermal influences so as to reduce an error in measuring air flow rate.

Abstract: A fuel injection control apparatus for controlling the amount and the timing of fuel injection with the aid of a microcomputer includes a hot-wire type flow sensor for detecting an instantaneous intake air flow velocity within an intake air passage of an internal combustion engine. The output signal of the hot-wire type flow sensor is sampled at every predetermined crank angle or at every predetermined time point to be stored in a RAM. The time at which the instantaneous velocity of the intake air flow within the intake passage becomes maximum is detected. The fuel injection timing of a fuel injection valve disposed in the intake passage is so controlled that the fuel injection is terminated around the time point at which the instantaneous intake air flow velocity is maximum.

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 fuel injection control apparatus for internal combustion engine includes an air flow meter provided in a path through which air is sucked into an internal combustion engine, a fuel injector for controlling the amount of fuel in response to a signal from the air flow meter to produce the mixture of sucked air and fuel, and an electrical control device including a microprocessor responsive to the signal from the air flow meter to produce, by computation of the microprocessor a signal for controlling the fuel injector. The microprocessor computes the fuel injection amount or duration and dead time on the basis of the signal from the air flow meter. The beginning of the fuel injection by the fuel injector is altered in accordance with the dead time which is variable with the air flow amount.

Abstract: A sensor for detecting the internal pressure is provided in the cylinder to detect the combustion condition in the engine cylinder. In order to process the output of the sensor in accordance with the volume of the combustion chamber, the amount of change of combustion volume between timings of fetching the sensor outputs is multiplied by the sensor output, or the sensor output is fetched in accordance with the amount of change of combustion volume. In this way, the amount of work is detected from the sensor output. The ignition timing is subjected to feedback control in such a manner as to attain the maximum effective amount of work.

Abstract: Disclosed is a fuel injection valve drive circuit for use in an internal combustion engine wherein the excitation current supplied to the fuel injection valve winding is controlled on a feedback basis so as to maintain the specified value during the period of the valve opening command signal. A control signal based on the difference between the signal representing the excitation current and the reference signal is produced, and the excitation current is controlled by the pulse width modulation signal which is produced based on the magnitude of the control signal.

Abstract: A control system employs a microcomputer, which controls the starting operation of a spark ignition type engine provided with a fuel injection system. The control system is loaded with, at least, contact information of an ignition switch for connecting an ignition device to a power supply and a starter switch for connecting a starter motor to the power supply, and an output signal of a temperature sensor for detecting the temperature of cooling water of the engine. Where the cooling water temperature is not higher than a predetermined temperature, a fuel pump which supplies pressurized fuel to an injector of the fuel injection system is started simultaneously with the closure of the ignition switch, and this fuel pump is stopped during the operation of the starter motor.

Abstract: A variable gain amplifier includes an amplifier for amplifying an input signal, a switch controlled with a given duty factor and a smoothing filter connected to the switch. The filter and the switch constitutes a negative feedback loop for the amplifier of which amplification factor is variably controlled by varying the duty factor of the switch.

Abstract: A device for controlling an electromechanical transducer such as a proportional electromagnetic valve, in which a pulse signal having a constant period shorter sufficiently than the minimum response time required for the displacement of the plunger of the proportional electromagnetic valve over its predetermined full stroke is applied to the electromagnetic coil of the proportional electromagnetic valve to superpose a very small vibratory stroke component on the stroke of the plunger, and the duty cycle of the pulse signal applied to the electromagnetic coil is varied so as to urge the plunger in directly proportional relation to the variation of the duty cycle without substantially giving rise to mechanical hysteresis in the stroke of the plunger.