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: An electronic control device having a high heat dissipating ability includes a printed board secured to an enclosure and interposed between a case and a cover with screws passing through the printed board. Thermally conductive thin film layers made of copper foil are formed in parallel on a mount face and an opposite mount face of the printed board and inside the printed board so as to be thermally separated from each other. A protrusion is provided on the cover and protrudes beyond a bottom part of the cover toward the position where an electronic component is mounted. A flexible, semi-solid thermally conductive material is placed between an end face of the protrusion and the opposite mount face of the printed board corresponding to the position where the electronic component is mounted to be in contact with the end face and the opposite mount face.

Abstract: An electronic control device includes a power supply circuit, electronic circuits, a ground wiring pattern, and a common ground wiring pattern formed in a multi-layered substrate. The ground wiring pattern is dedicated for the power supply circuit and the common ground wiring pattern is provided for all electronic circuits. Even when an electrical potential of the ground wiring pattern varies due to a switching operation of a switching component included in the power supply circuit, the common ground wiring pattern is not affected.

Abstract: An electronic control apparatus includes an exclusive power source wiring for a charge pump circuit which is discriminated from a common power source wiring. The exclusive power source wiring is connected to the common power source wiring via a via-hole va having the impedance larger than that of the wiring pattern. Similarly, the electronic control apparatus includes an exclusive ground wiring for the charge pump circuit which is discriminated from a common ground wiring. The exclusive ground wiring is connected to the common ground via an additional via-hole vb. Furthermore, a noise-suppressing capacitor C is connected between a power source wiring and a ground wiring. The power source wiring interposes between the via-hole va and the exclusive power source wiring, and the ground wiring interposes between the via-hole vb and the exclusive ground wiring.

Abstract: An ECU has a main IC and at least one auxiliary IC, with at least the auxiliary IC driving one or more MOS FETs to control supplying of power to respective electrical loads, e.g., in a vehicle. A stepped-up voltage, higher than the circuit power source voltage, is generated within the main IC and supplied to each auxiliary IC, for driving gate electrodes of the MOS FETs. Electrical noise produced by operation of a voltage step-up circuit in the main IC is effectively suppressed by elements that are coupled only to a power source terminal of the main IC alone.

Abstract: The power supply PS includes a voltage detecting circuit VD for detecting a voltage level Vs inputted from an external voltage source, a boot strap circuit BS, andET connected in parallel with BS, a smoothing circuit SM connected with the BS output terminal and a regulating IC connected with BS and FET. The regulating IC includes VD, a transistor Tr and condenser C. Both when a PS switch is turned on and when VD detects that Vs (which once descended) reaches an ascending reference, a high level driving signal generated by VD is changed into a low level signal, thereby turning off Tr connected with C. Thus, until Tr completes charging up C, a duty ratio of a pulse width modulation (PWM) signal dependent on the SM output is made gradually greater, thereby surely preventing a rush current by turning on and off the FET by the PWM signal.

Abstract: An electronic control device having a high heat dissipating ability includes a printed board secured to an enclosure and interposed between a case and a cover with screws passing through the printed board. Thermally conductive thin film layers made of copper foil are formed in parallel on a mount face and an opposite mount face of the printed board and inside the printed board so as to be thermally separated from each other. A protrusion is provided on the cover and protrudes beyond a bottom part of the cover toward the position where an electronic component is mounted. A flexible, semi-solid thermally conductive material is placed between an end face of the protrusion and the opposite mount face of the printed board corresponding to the position where the electronic component is mounted to be in contact with the end face and the opposite mount face.

Abstract: An electronic control device having a high heat dissipating ability includes a printed board secured to an enclosure and interposed between a case and a cover with screws passing through the printed board. Thermally conductive thin film layers made of copper foil are formed in parallel on a mount face and an opposite mount face of the printed board and inside the printed board so as to be thermally separated from each other. A protrusion is provided on the cover and protrudes beyond a bottom part of the cover toward the position where an electronic component is mounted. A flexible, semi-solid thermally conductive material is placed between an end face of the protrusion and the opposite mount face of the printed board corresponding to the position where the electronic component is mounted to be in contact with the end face and the opposite mount face.

Abstract: An electronic control device includes a power supply circuit, electronic circuits, a ground wiring pattern, and a common ground wiring pattern formed in a multi-layered substrate. The ground wiring pattern is dedicated for the power supply circuit and the common ground wiring pattern is provided for all electronic circuits. Even when an electrical potential of the ground wiring pattern varies due to a switching operation of a switching component included in the power supply circuit, the common ground wiring pattern is not affected.

Abstract: The power supply PS includes a voltage detecting circuit VD for detecting a voltage level Vs inputted from an external voltage source, a boot strap circuit BS, andET connected in parallel with BS, a smoothing circuit SM connected with the BS output terminal and a regulating IC connected with BS and FET. The regulating IC includes VD, a transistor Tr and condenser C. Both when a PS switch is turned on and when VD detects that Vs (which once descended) reaches an ascending reference, a high level driving signal generated by VD is changed into a low level signal, thereby turning off Tr connected with C. Thus, until Tr completes charging up C, a duty ratio of a pulse width modulation (PWM) signal dependent on the SM output is made gradually greater, thereby surely preventing a rush current by turning on and off the FET by the PWM signal.

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: An electronic control device having a high heat dissipating ability includes a printed board secured to an enclosure and interposed between a case and a cover with screws passing through the printed board. Thermally conductive thin film layers made of copper foil are formed in parallel on a mount face and an opposite mount face of the printed board and inside the printed board so as to be thermally separated from each other. A protrusion is provided on the cover and protrudes beyond a bottom part of the cover toward the position where an electronic component is mounted. A flexible, semi-solid thermally conductive material is placed between an end face of the protrusion and the opposite mount face of the printed board corresponding to the position where the electronic component is mounted to be in contact with the end face and the opposite mount face.

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: A driving apparatus for an electromagnetic valve comprises a conduction control circuit and a current-limit-value setting circuit. The conduction control circuit turns on and off an FET so that a conduction current flowing through the electromagnetic valve has a magnitude equal to a predetermined current limit value while a microcomputer is outputting a driving signal to the conduction control circuit. The predetermined current limit value is set at a first current limit value during a first predetermined period starting at a point of time the microcomputer outputs the driving signal. When the predetermined first period has lapsed, the predetermined current limit value is switched to a second current limit value for a second period. The second limit value is smaller than the first current limit value. A first off-time of the FET for attaining the first current limit value is set to be shorter than a second off-time of the FET for attaining the second current limit value.

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 driving apparatus for an electromagnetic valve which supplies fuel to an engine comprises a conduction control circuit and a current-limit-value setting circuit. The conduction control circuit turns on and off an FET so that a conduction current flowing through a coil of the electromagnetic valve has a magnitude equal to a predetermined current limit value while a microcomputer is outputting a driving signal to the conduction control circuit. The predetermined current limit value used in the conduction control circuit is set at a first current limit value during a predetermined period starting at a point of time the microcomputer outputs the driving signal. When the predetermined period has lapsed, the predetermined current limit value is switched from the first current limit value to a second current limit value which is smaller than the first current limit value.

Abstract: In a motor drive control, four MOSFETs are connected in an H-bridge configuration, and four diodes are connected in parallel with the MOSFETs, respectively. A pair of MOSFETs at the high side are forced to turn on to form a current circulation path including a direct current motor during a deenergization of the motor when a motor current is low. Thus, the energy in a motor coil is extinguished through the switching devices. The MOSFETs are forced to turn off to open the current circulation path during the deenergization of the motor when the motor current is high. Thus, the diodes are forward-biased to conduct and extinguish the energy in the motor coil through the diodes. According to this selective use of the switching devices or the diodes is effective to reduce a power loss over an entire range of motor currents.

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.