Abstract: A direct current motor for an engine throttle control is driven with a motor current of 100% duty ratio, when a throttle valve is to be moved from one throttle position to another or when the movement of the throttle valve is to be braked. The motor current is limited to a limit level, when the motor locks, that is, when the motor current continues to be in excess of the limit level for more than a predetermined period. The motor may be driven with a limited current at initial stages of moving the throttle valve, and with a further limited current when the motor lock is detected. The motor current is finally shut off, when the throttle valve is not rotated to the target position after the continuation of the limitation of the motor current for more than a predetermined period.

Abstract: A multi-output electric power source device has at least two channels for producing a constant voltage and a constant voltage from a single input voltage. Each channel is provided with a switching regulator in the input stages thereof and a series regulator in the next stage thereof. An over-heat detector circuit is provided in common for both channels. When the over-heating of either one of switching transistors in the channels is detected, the switching regulators turn off both switching transistors thereby to interrupt both output voltages from being supplied to an external circuit. When an over-voltage is detected, series regulators also interrupt the output voltages from being supplied to the external unit.

Abstract: A power control circuit includes a switching regulator for converting voltage of external electric power into a medium voltage, a series regulator for converting the medium voltage to a prescribed voltage of output power to be supplied and a circuit for operating either the switching regulator or the series regulator under a protective condition if overvoltage or overcurrent is detected. The switching regulator includes a first transistor, a smoothing circuit and a first control circuit for controlling switching operation of the first transistor. The series regulator includes a second transistor and a second control circuit for controlling conductivity of the second transistor to regulate voltage of the output power to be constant, an overvoltage detecting circuit for detecting an overvoltage of the medium voltage, and an overcurrent detecting circuit for detecting an overcurrent supplied to the series regulator.

Abstract: A multi-output electric power source device has at least two channels for producing a constant voltage and a constant voltage from a single input voltage. Each channel is provided with a switching regulator in the input stages thereof and a series regulator in the next stage thereof. An over-heat detector circuit is provided in common for both channels. When the over-heating of either one of switching transistors in the channels is detected, the switching regulators turn off both switching transistors thereby to interrupt both output voltages from being supplied to an external circuit. When an over-voltage is detected, series regulators also interrupt the output voltages from being supplied to the external unit.

Abstract: A power control circuit includes a switching regulator for converting voltage of external electric power into a medium voltage, a series regulator for converting the medium voltage to a prescribed voltage of output power to be supplied and a circuit for operating either the switching regulator or the series regulator under a protective condition if overvoltage or overcurrent is detected. The switching regulator includes a first transistor, a smoothing circuit and a first control circuit for controlling switching operation of the first transistor. The series regulator includes a second transistor and a second control circuit for controlling conductivity of the second transistor to regulate voltage of the output power to be constant, an overvoltage detecting circuit for detecting an overvoltage of the medium voltage, and an overcurrent detecting circuit for detecting an overcurrent supplied to the series regulator.

Abstract: A direct current motor for an engine throttle control is driven with a motor current of 100% duty ratio, when a throttle valve is to be moved from one throttle position to another or when the movement of the throttle valve is to be braked. The motor current is limited to a limit level, when the motor locks, that is, when the motor current continues to be in excess of the limit level for more than a predetermined period. The motor may be driven with a limited current at initial stages of moving the throttle valve, and with a further limited current when the motor lock is detected. The motor current is finally shut off, when the throttle valve is not rotated to the target position after the continuation of the limitation of the motor current for more than a predetermined period.

Abstract: In an electric load driving device, in the case of a high-side output mode, an output FET is supplied, when connected with a higher-potential side than a load, at its gate with a boosted voltage higher than a battery voltage in response to one control signal as selected from two control signals by a switch signal. In the case of a low-side output mode, the FET is supplied, when connected with a lower-potential side than the load, at its gate with the battery voltage in response to the selected signal. These cases are switched in response to a signal indicating the bit value of the output mode setting data which are stored in advance in a nonvolatile memory.

Abstract: An electrical load driving device is constructed to accurately detect an over-current state in either a high-side output mode or a low-side output mode irrespective of voltage fluctuations of a load power supply. The over-current is detected by a detection voltage which decreases from a battery voltage in proportion to a current flowing through an output transistor being compared with a determination voltage in the high-side output mode. It is detected by a second detection voltage which increases from a ground potential in proportion to the current flowing through the output transistor being compared with a determination voltage in the low-side output mode.

Abstract: A plurality of ceramic circuit boards mounted with heat-generative driving transistors and other electronic parts are bonded to a heat radiating fin, and the heat radiating fin is connected to a motherboard. Heat generated by the driving transistors can efficiently be absorbed and dissipated by the heat radiating fin, and assembling work necessary for combining the components to the motherboard can be reduced. The electronic parts, wiring patterns and the like on the circuit boards can simultaneously be encapsulated in a resin or the like after bonding the circuit boards to the heat radiating fin, packaging work can be reduced.

Abstract: A direct current motor for an engine throttle control is driven with a motor current of 100% duty ratio, when a throttle valve is to be moved from one throttle position to another or when the movement of the throttle valve is to be braked. The motor current is limited to a limit level, when the motor locks, that is, when the motor current continues to be in excess of the limit level for more than a predetermined period. The motor may be driven with a limited current at initial stages of moving the throttle valve, and with a further limited current when the motor lock is detected. The motor current is finally shut off, when the throttle valve is not rotated to the target position after the continuation of the limitation of the motor current for more than a predetermined period.

Abstract: In an electric load driving device, in the case of a high-side output mode, an output FET is supplied, when connected with a higher-potential side than a load, at its gate with a boosted voltage higher than a battery voltage in response to one control signal as selected from two control signals by a switch signal. In the case of a low-side output mode, the FET is supplied, when connected with a lower-potential side than the load, at its gate with the battery voltage in response to the selected signal. These cases are switched in response to a signal indicating the bit value of the output mode setting data which are stored in advance in a nonvolatile memory.

Abstract: An electrical load driving device is constructed to accurately detect an over-current state in either a high-side output mode or a low-side output mode irrespective of voltage fluctuations of a load power supply. The over-current is detected by a detection voltage which decreases from a battery voltage in proportion to a current flowing through an output transistor being compared with a determination voltage in the high-side output mode. It is detected by a second detection voltage which increases from a ground potential in proportion to the current flowing through the output transistor being compared with a determination voltage in the low-side output mode.

Abstract: A case which accommodates electronic control circuit is housed in a housing box. An air passage is formed between the case and a main body of the housing box to introduce cooling air for cooling an electronic control circuit in the case. A heat sink is attached to an inner surface of the case by a screw placed in a through hole formed in an area of the case to which the cooling air is not introduced. Accordingly, the electronic control circuit in the case is prevented from dust, water and the like. Further, the electronic control circuit is efficiently cooled down by the cooling air passes through the air passage via the heat sink and the case because an exothermic electronic element of the electronic control circuit is making a contact with the heat sink.

Abstract: A plurality of ceramic circuit boards mounted with heat-generative driving transistors and other electronic parts are bonded to a heat radiating fin, and the heat radiating fin is connected to a motherboard. Heat generated by the driving transistors can efficiently be absorbed and dissipated by the heat radiating fin, and assembling work necessary for combining the components to the motherboard can be reduced. The electronic parts, wiring patterns and the like on the circuit boards can simultaneously be encapsulated in a resin or the like after bonding the circuit boards to the heat radiating fin, packaging work can be reduced.

Abstract: The present invention provides an abnormality detecting device for a vehicle communication system comprising controllers and a diagnosis unit. The controllers store data to be transmitted by means of a communication IC to the diagnosis unit. When data is transmitted to a bus at a first timing, a communication abnormality, if any, around the communication IC is detected in response to the status of data stored in the communication IC at a second timing by a CPU. The CPU determines as an abnormality a case where, after transmission of data from the communication IC to the bus, the data is kept stored in the communication IC. The CPU determines as an abnormality a case where, after transmission of part of data to the communication IC, no data is stored in the communication IC.

Abstract: An electronic control apparatus for use in vehicles comprised of two, one-chip microcomputers. The microcomputers each have a ROM and a RAM and are used to control different systems provided in the vehicle. The ROM of the second microcomputer stores an operational program which can be used to calculate control values for controlling various types of devices. It also stores operational map data which can be used to calculate control values for controlling various types of devices. Various signals output by the sensors provided in the vehicle are supplied to both microcomputers. At the start of the power supply to the apparatus, the operational map data stored in the ROM of the first microcomputer, which is to be used by the second microcomputer, is transferred to the RAM of the second microcomputer. The second microcomputer calculates a control value from the transferred operational map data, the signals output by the sensors and other data, thereby controlling the system assigned to it.

Abstract: In an air-fuel ratio control apparatus for engines, when a vehicle is brought to a stop and the engine comes into an idling operation, the average value of air-fuel ratio correction amount is decreased by a given amount and the air-fuel ratio control is started again from the decreased value by means of an average value hold circuit.

Abstract: In an air-fuel ratio control apparatus for detecting the air-fuel ratio from the oxygen content of the exhaust gas from an engine and feedback controlling the air-fuel ratio at the desired ratio through an integrating circuit, the circuit constant of the integrating circuit is increased with increase in the altitude to improve the control response characteristic.

Abstract: An air-fuel ratio control system for engines comprises a control unit by which the air-fuel ratio is maintained constant to enrich the mixture gas for a first predetermined time length after the detection of an engine heavy load condition, the air-fuel ratio is controlled as predetermined on the basis of an oxygen detection signal for a second predetermined time length after the lapse of the first predetermined time length, and the air-fuel ratio is restored to the constant value thereby to enrich the mixture gas after the lapse of the second predetermined time length.

Abstract: In an air-fuel ratio control system for internal combustion engines, an electronic control unit supplies a drive signal to an air-fuel ratio actuator in response to signals from an oxygen sensor and a heavy load sensor. The electronic control unit holds the air-fuel ratio compensation signal to a predetermined value when the heavy load sensor detects that a predetermined time has not passed since the engine enters a heavy load condition, and changes the air fuel ratio compensation signal to a predetermined value associated with the rich mixture when it is detected that the predetermined time has passed.