Power circuit of a vehicular electronic control unit
First Claim
1. A power circuit of a vehicular electronic control unit including a microprocessor for driving various electric loads in accordance with operation states of various input sensors and contents of a program memory, the power circuit comprising a constant voltage power circuit, an awakening timer circuit, and first and second power supply circuits each of which is supplied with power from a vehicle battery, wherein:
- the constant voltage power circuit is supplied with power from the vehicle battery via the first or second power supply circuit;
the awakening timer circuit generates an awakening trigger signal upon a lapse of a prescribed time from a stop of power supply to the microprocessor;
the first power supply circuit comprises an output contact as a first opening/closing element and a coil for closing the output contact; and
the second power supply circuit comprises a second opening/closing element that is provided between the vehicle battery and the constant voltage power circuit and is closed in response to the awakening trigger signal.
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Accused Products
Abstract
A power circuit of a vehicular electronic control unit is provided with a constant voltage power circuit, an awakening timer circuit, and first and second power supply circuits each of which is supplied with power from a vehicle battery. The constant voltage power circuit is supplied with power from the vehicle battery via the first and second power supply circuits. The awakening timer circuit generates an awakening trigger signal upon a lapse of a prescribed time from a stop of power supply to the microprocessor. The first power supply circuit has an output contact as a first opening/closing element and a coil for closing the output contact. The second power supply circuit has a second opening/closing element that is provided between the vehicle battery and the constant voltage power circuit and is closed at least in response to the awakening trigger signal.
16 Citations
9 Claims
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1. A power circuit of a vehicular electronic control unit including a microprocessor for driving various electric loads in accordance with operation states of various input sensors and contents of a program memory, the power circuit comprising a constant voltage power circuit, an awakening timer circuit, and first and second power supply circuits each of which is supplied with power from a vehicle battery, wherein:
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the constant voltage power circuit is supplied with power from the vehicle battery via the first or second power supply circuit;
the awakening timer circuit generates an awakening trigger signal upon a lapse of a prescribed time from a stop of power supply to the microprocessor;
the first power supply circuit comprises an output contact as a first opening/closing element and a coil for closing the output contact; and
the second power supply circuit comprises a second opening/closing element that is provided between the vehicle battery and the constant voltage power circuit and is closed in response to the awakening trigger signal. - View Dependent Claims (3, 5, 6, 7)
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2. A power circuit of a vehicular electronic control unit including a microprocessor that is supplied with power from a vehicle battery and drives various electric loads in accordance with operation states of various input sensors and contents of a program memory, the power circuit comprising:
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a constant voltage power circuit that is supplied with power from the vehicle battery via the first or second power supply circuit, and that supplies a prescribed regulated voltage to the microprocessor, devices accompanying the microprocessor including the program memory and a RAM for computation, and input/output interface circuits;
an awakening timer circuit that is supplied with power directly from the vehicle battery, and generates an awakening trigger signal upon a lapse of a prescribed time from a stop of power supply to the microprocessor;
a first power supply circuit that comprises a power relay having an output contact as a first opening/closing element provided between the vehicle battery and the constant voltage power circuit or between and the vehicle battery and the various electric loads, and a coil for closing the output contact, and a reverse-blocking diode connected in series to the output contact, wherein the coil being energized when a power switch is turned on and kept energized by a power maintenance drive signal generated by the microprocessor even if the power switch is turned off; and
a second power supply circuit comprises a second opening/closing element that connects the vehicle battery and the constant voltage power circuit, and is closed in response to the awakening trigger signal and kept closed by a power maintenance drive signal generated by the microprocessor, wherein the reverse-blocking diode is in such a connection relationship as to allow power supply from the first power supply circuit to the various electric loads and to prohibit power supply from the second power supply circuit to the various electric loads.
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4. A power circuit of a vehicular electronic control unit comprising a microprocessor that is supplied with power from a vehicle battery and drives various electric loads in accordance with operation states of various input sensors and contents of a program memory, the power circuit comprising:
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a constant voltage power circuit that is supplied with power from the vehicle battery via the first or second power supply circuit, and that supplies a prescribed regulated voltage to the microprocessor, devices accompanying the microprocessor including the program memory and a RAM for computation, and input/output interface circuits;
an awakening timer circuit that is supplied with power directly from the vehicle battery, and generates an awakening trigger signal upon a lapse of a prescribed time from a stop of power supply to the microprocessor;
a first power supply circuit that comprises a power relay having an output contact as a first opening/closing element provided between the vehicle battery and the constant voltage power circuit or between and the vehicle battery and the various electric loads, and a coil for closing the output contact, and a reverse-blocking diode connected in series to the output contact, wherein the coil being energized when a power switch that is manipulated to start driving of a vehicle is turned on and kept energized by a power maintenance drive signal generated by the microprocessor even if the power switch is turned off; and
a second power supply circuit comprises a second power relay having an output contact as a second opening/closing element provided between the vehicle battery and the constant voltage power circuit, and a coil for closing the output contact, wherein the coil being energized in response to the awakening trigger signal and kept energized by a power maintenance drive signal generated by the microprocessor, wherein the reverse-blocking diode is in such a connection relationship as to allow power supply from the first power supply circuit to the various electric loads and to prohibit power supply from the second power supply circuit to the various electric loads. - View Dependent Claims (8, 9)
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Specification