Power circuit
First Claim
1. A power circuit comprising:
- a battery;
a load;
a boost circuit provided between the battery and the load, wherein the boost circuit includes;
a boost switching element;
a coil provided between the battery and the boost switching element; and
a rectifier element provided between the coil and the load,a first switch connected to the boost circuit in parallel;
a current detection circuit detecting current flowing through the first switch; and
a control circuit turning on the first switch during a normal state other than a restart of an engine after an idling stop, the control circuit turning off the first switch and controlling an operation of the boost switching element at a restart of the engine after an idling stop so that voltage of the battery is boosted and supplied to the load, wherein the control circuit determines based on the current detected by the current detection circuit during the normal state whether or not the first switch has an open fault, wherein after the restart of the engine and before the normal state, the control circuit reads a value of the current detected by the current detection circuit and sets the read value as an offset value, and wherein after the normal state and before the restart of the engine, the control circuit reads a value of the current detected by the current detection circuit and corrects the read value by the offset value.
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Accused Products
Abstract
A power circuit includes a boost circuit having a boost switching element, a coil provided between a battery and the boost switching element and a rectifier element provided between the coil and a load, a first switch connected to the boost circuit in parallel, a current detection circuit detecting current flowing through the first switch and a control circuit turning on the first switch during a normal state other than a restart of an engine after an idling stop and turning off the first switch and controlling an operation of the boost switching element at a restart of the engine after an idling stop so that voltage of the battery is boosted and supplied to the load. The control circuit determines based on the current detected by the current detection circuit during the normal state whether or not the first switch has an open fault.
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Citations
9 Claims
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1. A power circuit comprising:
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a battery; a load; a boost circuit provided between the battery and the load, wherein the boost circuit includes; a boost switching element; a coil provided between the battery and the boost switching element; and a rectifier element provided between the coil and the load, a first switch connected to the boost circuit in parallel; a current detection circuit detecting current flowing through the first switch; and a control circuit turning on the first switch during a normal state other than a restart of an engine after an idling stop, the control circuit turning off the first switch and controlling an operation of the boost switching element at a restart of the engine after an idling stop so that voltage of the battery is boosted and supplied to the load, wherein the control circuit determines based on the current detected by the current detection circuit during the normal state whether or not the first switch has an open fault, wherein after the restart of the engine and before the normal state, the control circuit reads a value of the current detected by the current detection circuit and sets the read value as an offset value, and wherein after the normal state and before the restart of the engine, the control circuit reads a value of the current detected by the current detection circuit and corrects the read value by the offset value. - View Dependent Claims (2, 3, 4, 9)
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5. A power circuit comprising:
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a battery; a load; a boost circuit provided between the battery and the load, wherein the boost circuit includes; a boost switching element; a coil provided between the battery and the boost switching element; and a rectifier element provided between the coil and the load, a first switch connected to the boost circuit in parallel; a potential difference output circuit detecting potential difference between input voltage and output voltage of the boost circuit; and a control circuit turning on the first switch during a normal state other than a restart of an engine after an idling stop, the control circuit turning off the first switch and controlling an operation of the boost switching element at a restart of the engine after an idling stop so that voltage of the battery is boosted and supplied to the load, wherein the control circuit determines based on the potential difference detected by the potential difference output circuit during the normal state whether or not the first switch has an open fault, and wherein during the normal state, if the potential difference outputted by the potential difference detection circuit is a threshold value or greater when the first switch is turned on, the control circuit determines that the first switch has an open fault. - View Dependent Claims (6, 7, 8)
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Specification