VOLTAGE DETECTION APPARATUS AND COMBINATION CIRCUIT
First Claim
1. A voltage detection apparatus, comprising:
- an operational amplifier;
a first switch coupled between a high potential side terminal of a detection target voltage source and a common node;
a second switch coupled between a low potential side terminal of the detection target voltage source and the common node;
a first capacitor including a plurality of capacitor elements coupled in series between the common node and an inverting input terminal of the operational amplifier;
a third switch coupled between the inverting input terminal and an output terminal of the operational amplifier;
a second capacitor coupled between the inverting input terminal and output terminal of the operational amplifier;
a reference voltage selection circuit which selects one of a first reference voltage and a second reference voltage differing from one another, and applies a selected reference voltage to a non-inverting input terminal of the operational amplifier; and
a controller which is capable of selecting a voltage detection mode and a self-diagnostic mode, whereinin the voltage detection mode, the controller uses the reference voltage selection circuit to select the first reference voltage and sets charge in the first capacitor by closing the third switch and closing the first switch, and subsequently, the controller detects an interterminal voltage of the detection target voltage source based on an output voltage of the operational amplifier after opening the third switch and first switch and closing the second switch, andin the self-diagnostic mode, the controller uses the reference voltage selection circuit to select one of the first reference voltage and the second reference voltage and sets charge in the first capacitor by closing the third switching and closing one of the first switch and the second switch, and subsequently, the controller carries out a fault diagnosis based on an output voltage of the operational amplifier after opening the third switch and selecting the other one of the first reference voltage and second reference voltage using the reference voltage selection circuit.
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Accused Products
Abstract
A voltage detection apparatus includes an operational amplifier, first and second switches coupled between a terminal of a detection target voltage source and a common node, a first capacitor including a plurality of capacitor elements coupled in series between the common node and an inverting input terminal of the operational amplifier, a third switch and a second capacitor, which are coupled between the inverting input terminal and an output terminal of the operational amplifier, a reference voltage selection circuit which applies one of a first reference voltage and a second reference voltage differing from one another to a non-inverting input terminal of the operational amplifier, and a controller which is capable of selecting a voltage detection mode and a self-diagnostic mode.
28 Citations
14 Claims
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1. A voltage detection apparatus, comprising:
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an operational amplifier; a first switch coupled between a high potential side terminal of a detection target voltage source and a common node; a second switch coupled between a low potential side terminal of the detection target voltage source and the common node; a first capacitor including a plurality of capacitor elements coupled in series between the common node and an inverting input terminal of the operational amplifier; a third switch coupled between the inverting input terminal and an output terminal of the operational amplifier; a second capacitor coupled between the inverting input terminal and output terminal of the operational amplifier; a reference voltage selection circuit which selects one of a first reference voltage and a second reference voltage differing from one another, and applies a selected reference voltage to a non-inverting input terminal of the operational amplifier; and a controller which is capable of selecting a voltage detection mode and a self-diagnostic mode, wherein in the voltage detection mode, the controller uses the reference voltage selection circuit to select the first reference voltage and sets charge in the first capacitor by closing the third switch and closing the first switch, and subsequently, the controller detects an interterminal voltage of the detection target voltage source based on an output voltage of the operational amplifier after opening the third switch and first switch and closing the second switch, and in the self-diagnostic mode, the controller uses the reference voltage selection circuit to select one of the first reference voltage and the second reference voltage and sets charge in the first capacitor by closing the third switching and closing one of the first switch and the second switch, and subsequently, the controller carries out a fault diagnosis based on an output voltage of the operational amplifier after opening the third switch and selecting the other one of the first reference voltage and second reference voltage using the reference voltage selection circuit. - View Dependent Claims (3, 4, 5, 6, 7)
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2. The voltage detection apparatus according to claim 2, wherein
the detection target voltage source includes a plurality of unit batteries which configures an assembled battery by being coupled in series with the same polarity, and the first switch and second switch of each of the unit batteries are used in common respectively with the second and first switch of an adjacent unit battery.
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8. A voltage detection apparatus comprising:
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an operational amplifier having a differential output configuration; a first switch coupled between one terminal of a detection target voltage source and a first common node; a second switch coupled between the other terminal of the detection target voltage source and a second common node; a first upstream capacitor including a plurality of capacitor elements coupled in series between the first common node and an inverting input terminal of the operational amplifier; a second upstream capacitor including a plurality of capacitor elements coupled in series between the second common node and a non-inverting input terminal of the operational amplifier; a first parallel switch coupled between the inverting input terminal and a non-inverting output terminal of the operational amplifier; a second parallel switch coupled between the non-inverting input terminal and an inverting output terminal of the operational amplifier; a first downstream capacitor and a first series switch coupled in series between the inverting input terminal and the non-inverting output terminal of the operational amplifier; a second downstream capacitor and a second series switch coupled in series between the non-inverting input terminal and the inverting output terminal of the operational amplifier; a node switch coupled between the first common node and second common node; a first reference voltage selection circuit which is capable of applying a first reference voltage or a second reference voltage to a common connection point of the first downstream capacitor and the first series switch; a second reference voltage selection circuit which is capable of applying a third reference voltage and a fourth reference voltage to a common connection point of the second downstream capacitor and the second series switch; and a controller which is capable of selecting a voltage detection mode and a self-diagnostic mode, wherein in the voltage detection mode, the controller opens the first series switch, the second series switch, and the node switch, uses the first reference voltage selection circuit and the second reference voltage selection circuit to apply the first reference voltage and the third reference voltage respectively, and closes the first parallel switch and the second parallel switch and closes the first switch and the second switch, thereby charging in the first upstream capacitor, the second upstream capacitor, the first downstream capacitor, and the second downstream capacitor, and subsequently, the controller detects an interterminal voltage of the detection target voltage source based on a differential output voltage of the operational amplifier after opening the first switch, the second switch, the first parallel switch, and the second parallel switch, stopping the voltage application using the first reference voltage selection circuit and second reference voltage selection circuit, and closing the first series switch, the second series switch, and the node switch, and in the self-diagnostic mode, the controller closes the node switch after having opened at least one of the first switch and the second switch, closes the first parallel switch and the second parallel switch, opens the first series switch and the second series switch, and uses the first reference voltage selection circuit and second reference voltage selection circuit to apply the second reference voltage and the fourth reference voltage respectively, thereby setting charge in the first upstream capacitor, the second upstream capacitor, the first downstream capacitor, and the second downstream capacitor, and subsequently, the controller carries out a fault diagnosis based on a differential output voltage of the operational amplifier after opening the first parallel switch and the second parallel switch, stopping the voltage application using the first reference voltage selection circuit and the second reference voltage selection circuit, and closing the first series switch and the second series switch. - View Dependent Claims (9, 10, 11, 12)
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13. A combination circuit, comprising:
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a first capacitor including a plurality of capacitor elements coupled in series between a signal output node of a first circuit which operates in a first power supply system and a signal input node of a second circuit which operates in a second power supply system; an operational amplifier; a diagnostic switch coupled between the signal input node and an inverting input terminal of the operational amplifier; a parallel switch coupled between the inverting input terminal and an output terminal of the operational amplifier; a second capacitor including one capacitor coupled, or a plurality of capacitor elements coupled in series, between the inverting input terminal and the output terminal of the operational amplifier; a reference voltage selection circuit which selects one of a first reference voltage and a second reference voltage differing from one another, and applies a selected reference voltage to a non-inverting input terminal of the operational amplifier; and a controller which is selectable a signal transmission mode and a self-diagnostic mode, wherein in the signal transmission mode, the controller opens the diagnostic switch, thereby transmitting a signal from the signal output node to the signal input node, and in the self-diagnostic mode, the controller outputs a constant voltage from the first circuit to the signal output node, uses the reference voltage selection circuit to select one of the first reference voltage and the second reference voltage, and closes the diagnostic switch and the third switch, thereby setting charge in the first capacitor, and subsequently, the controller carries out a fault diagnosis based on an output voltage of the operational amplifier after opening the third switch, and using the reference voltage selection circuit to select the other one of the first reference voltage and second reference voltage.
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14. A combination circuit, comprising:
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a first upstream capacitor and second upstream capacitor each including a plurality of capacitor elements coupled in series between a differential signal output node of a first circuit which operates in a first power supply system and a differential signal input node of a second circuit which operates in a second power supply system; an operational amplifier having a differential output configuration; a first diagnostic switch coupled between one of the differential signal input nodes and an inverting input terminal of the operational amplifier; a second diagnostic switch coupled between the other one of the differential signal input nodes and a non-inverting input terminal of the operational amplifier; a first parallel switch coupled between the inverting input terminal and a non-inverting output terminal of the operational amplifier; a second parallel switch coupled between the non-inverting input terminal and an inverting output terminal of the operational amplifier; a first downstream capacitor including one or a plurality of capacitor elements coupled in series, and a first series switch, coupled between the inverting input terminal and the non-inverting output terminal of the operational amplifier; a second downstream capacitor including one or a plurality of capacitor elements coupled in series, and a second series switch, coupled between the non-inverting input terminal and the inverting output terminal of the operational amplifier; a first reference voltage selection circuit which is capable of applying a first reference voltage to a common connection point of the first downstream capacitor and the first series switch; a second reference voltage selection circuit which is capable of applying a second reference voltage to a common connection point of the second downstream capacitor and the second series switch; and a controller which is capable of selecting a signal transmission mode and a self-diagnostic mode, wherein in the signal transmission mode, the controller opens the first diagnostic switch and the second diagnostic switch, thereby transmitting a signal from the differential signal output node to the differential signal input node, and in the self-diagnostic mode, the controller outputs a constant voltage from the first circuit to the differential signal output node, closes the first parallel switch and second parallel switch, opens the first series switch and second series switch, and uses the first reference voltage selection circuit and the second reference voltage selection circuit to apply the first reference voltage and the second reference voltage respectively, thereby setting charge in the first upstream capacitor, the second upstream capacitor, the first downstream capacitor, and the second downstream capacitor, and subsequently, the controller carries out a fault diagnosis based on a differential output voltage of the operational amplifier after opening the first parallel switch and the second parallel switch, stopping the voltage application using the first reference voltage selection circuit and the second reference voltage selection circuit, and closing the first series switch and the second series switch.
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Specification