Abstract: The isolator includes a photodiode (first photodiode), a first and a second amplifier, and a carrier discharging circuit. The photodiode is an input element that converts an optical signal input from an LED (signal source) into an electrical signal, and outputs the electrical signal to the first amplifier. The first amplifier includes two bipolar transistors, and amplifies the electrical signal output by the photodiode. The first amplifier also includes three resistances, one of which is a feedback resistance. The second amplifier has a similar structure to that of the first amplifier. The carrier discharging circuit is connected to the base of the bipolar transistor in the first amplifier and to the base of the bipolar transistor in the second amplifier, so as to discharge, when the photodiode turns off, a carrier accumulated in these bases when the photodiode PD1 is on.

Abstract: In an FET device having a pair of input terminals, a pair of output terminals, a plurality of FETs and driving circuits, the driving circuit has such a circuit structure that source electrodes of the FETs are electrically connected to each other. Each of gate electrodes of the FETs is independently connected to a photo-diode array. The gate electrodes of the FETs are not electrically short-circuited to each other. The FETs are tuned on and off in response to a single control signal.

Abstract: An automatic engine stop-start system automatically stops an engine to reduce the fuel consumption whenever a predetermined condition is fulfilled and automatically starts the engine whenever another predetermined condition is fulfilled. This system is particularly arranged to detect gearshift lever position of an automatic transmission to determine various automatic stop/start conditions so that an engine in a car with an automatic transmission can be automatically stopped/started.

Abstract: An automotive vehicle control system is equipped with a main electronic control unit for controlling devices mounted on the vehicle, and an emergency electronic control unit for backing up the main electronic control unit. Both electronic control units transmit diagnostic signals, receive the diagnostic signals from each other and diagnose them for abnormalities, whereby a fault in the main electronic control unit is diagnosed by the emergency electronic control unit and a fault in the emergency electronic control unit is diagnosed by the main electronic control unit.

Abstract: A power supply control device is provided which supplies electric power to an automobile electronic control system, including a microcomputer, which controls devices on an automobile, such as a gear transmission, a clutch, etc. A power supply for the electronic control system is connected to a self-holding device for continuously supplying electric power to the electronic control system even if a key switch is turned off in error, resulting in a power cutoff. When the power is cut off inadvertently or intentionally, the electronic control system detects such a power cutoff, and effects a predetermined control operation. Upon completion of the operation, the electronic control system turns off the self-holding device to cut off the electric power supplied to the electronic control system.

Abstract: At an initial shifting operation of an automatic transmission, a shift actuator is operated to move a shift fork shaft to an initial target gear shift position which is deepest, followed by removing driving force from the actuator. A value is then read in from a stroke sensor for sensing the position of the actuator that prevails when a detent mechanism of the transmission is in a stable state. Shifting control is performed by using the read value as a target value for the next shifting operation.