Abstract: The voltage conversion apparatus includes a voltage holding unit that holds a maximum voltage of an output voltage and a determination unit that determines whether or not the maximum voltage held by the voltage holding unit is within a predetermined voltage range; when starting control of opening/closing operation by an opening/closing device, a control unit makes the opening/closing device perform the opening/closing operation, based on a predetermined starting switching frequency and a predetermined starting duty; the determination unit detects a failure in a smoothing capacitor by determining that the held maximum voltage is out of the voltage range.

Abstract: Provided is an on-vehicle electronic control device with low cost and low power consumption for performing monitoring control in both a driving mode and a parking mode of a vehicle. A main CPU is supplied with electric power from an on-vehicle battery via a power switching element and a main power supply circuit so as to control a plurality of electric loads in accordance with operating states of a plurality of input sensors. A sub CPU connected to the main CPU via a serial interface is supplied with electric power from the on-vehicle battery via a sub power supply circuit so as to monitor operations of the main CPU and input signals. The sub CPU has low speed and small memory capacity so as to operate with lower power consumption compared with the main CPU.

Abstract: Provided is an on-vehicle electronic control device with low cost and low power consumption for performing monitoring control in both a driving mode and a parking mode of a vehicle. A main CPU is supplied with electric power from an on-vehicle battery via a power switching element and a main power supply circuit so as to control a plurality of electric loads in accordance with operating states of a plurality of input sensors. A sub CPU connected to the main CPU via a serial interface is supplied with electric power from the on-vehicle battery via a sub power supply circuit so as to monitor operations of the main CPU and input signals. The sub CPU has low speed and small memory capacity so as to operate with lower power consumption compared with the main CPU.

Abstract: In an on-vehicle electronic control unit, error in output voltages from a constant voltage power supply circuit (C.V.P.S.) for use in a reference power supply of an A/D converter, occurs due to temperature rise. Whereby, there is a problem of the decrease of an A/D conversion accuracy. A C.V.P.S. supplies a voltage to analog sensors and to an AD converter. Furthermore, an output from a temperature sensor that is disposed in the neighborhood of the C.V.P.S. is stored in a memory as a contrast temperature data T at a time point of shipping. In addition, voltage fluctuation characteristic data due to the change of temperatures of the C.V.P.S. and detection fluctuation characteristic data accompanied by the change of voltages of the analog sensor group have preliminarily been stored, and the fluctuations in digital converted values accompanied with the change of temperatures in the neighborhood of the C.V.P.S. are compensated.