Battery charge/discharge monitoring circuit and method
First Claim
1. A circuit for monitoring charge/discharge of a battery, comprising:
- a first terminal connected to one end of a single current detection resistor serially connected to the battery so as to detect a charge current or a discharge current of the battery;
a second terminal connected to the other end of the current detection resistor;
a converter that converts a terminal potential of the first terminal at which a potential of the one end of the current detection resistor appears and a terminal potential of the second terminal at which a potential of the other end of the current detection resistor appears, into currents respectively;
a first terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the first terminal;
a second terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the second terminal;
a comparator that compares the integrated voltages developed by the first and second terminal capacitors with a reference voltage; and
an output section that outputs a difference betweenthe number of times of change in an output of the comparator, the output changing when the integrated voltage of the first terminal capacitor reaches the reference voltage, andthe number of times of change in an output of the comparator, the output changing when the integrated voltage of the second terminal capacitor reaches the reference voltage.
6 Assignments
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Accused Products
Abstract
A circuit for monitoring charge/discharge of a battery is disclosed. The circuit may comprise first and second terminal capacitors disposed for first and second terminals of a current detection resistor connected to a battery. The first and second terminal capacitors may develop an integrated voltage responsive to the charge/discharge current obtained from the individual terminals. The circuit may also include at least one comparator for comparing the individual integrated voltages developed by the first and second terminal capacitors with a reference voltage, the comparator having respective outputs which change when the individual integrated voltages reach the reference voltage. A terminal-by-terminal output change count difference output unit may count the number of times the output of the comparator changes and may output the difference between the number of times of change corresponding to the first terminal and the number of times of change corresponding to the second terminal.
20 Citations
13 Claims
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1. A circuit for monitoring charge/discharge of a battery, comprising:
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a first terminal connected to one end of a single current detection resistor serially connected to the battery so as to detect a charge current or a discharge current of the battery; a second terminal connected to the other end of the current detection resistor; a converter that converts a terminal potential of the first terminal at which a potential of the one end of the current detection resistor appears and a terminal potential of the second terminal at which a potential of the other end of the current detection resistor appears, into currents respectively; a first terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the first terminal; a second terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the second terminal; a comparator that compares the integrated voltages developed by the first and second terminal capacitors with a reference voltage; and an output section that outputs a difference between the number of times of change in an output of the comparator, the output changing when the integrated voltage of the first terminal capacitor reaches the reference voltage, and the number of times of change in an output of the comparator, the output changing when the integrated voltage of the second terminal capacitor reaches the reference voltage. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of monitoring charge/discharge of a battery, comprising the steps of:
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converting a terminal potential of the first terminal at which a potential of one end of a single current detection resistor serially connected to the battery appears and a terminal potential of the second terminal at which a potential of the other end of the current detection resistor appears, into a current respectively so as to detect a charge current or discharge current of the battery; developing an integrated voltage with supply of the current as converted from the terminal potential of the first terminal; developing an integrated voltage with supply of the current as converted from the terminal potential of the second terminal; comparing the integrated voltage corresponding to the terminal potential of the first terminal and the integrated voltage corresponding to the terminal potential of the second terminal with a reference voltage respectively; and outputting a difference between the number of times that the integrated voltage corresponding to the terminal potential of the first terminal reaches the reference voltage, and the number of times that the integrated voltage corresponding to the terminal potential of the second terminal reaches the reference voltage.
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11. A circuit for monitoring charge/discharge of a battery, comprising:
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a first terminal connected to one end of a current detection resistor serially connected to the battery so as to detect a charge current or a discharge current of the battery; a second terminal connected to the other end of the current detection resistor; a converter shared between the first and second terminals, that converts a terminal potential of the first terminal at which a potential of the one end of the current detection resistor appears and a terminal potential of the second terminal at which a potential of the other end of the current detection resistor appears, into currents respectively; a first terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the first terminal; a second terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the second terminal; a switching section that connects the first terminal to an input of the converter and connects the output of the converter to the first terminal capacitor, or that connects the second terminal to an input of the converter and connects the output of the converter to the second terminal capacitor; a comparator that compares the integrated voltages developed by the first and second terminal capacitors with a reference voltage; and an output section that outputs a difference between the number of times of change in an output of the comparator, the output changing when the integrated voltage of the first terminal capacitor reaches the reference voltage, and the number of times of change in an output of the comparator, the output changing when the integrated voltage of the second terminal capacitor reaches the reference voltage.
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12. A circuit for monitoring charge/discharge of a battery, comprising:
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a first terminal connected to one end of a single current detection resistor serially connected to the battery so as to detect a charge current or a discharge current of the battery; a second terminal connected to the other end of the current detection resistor; a converter that converts a terminal potential of the first terminal at which a potential of the one end of the current detection resistor appears and a terminal potential of the second terminal at which a potential of the other end of the current detection resistor appears, into currents respectively; a first terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the first terminal; a second terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the second terminal; a comparator that compares the integrated voltages developed by the first and second terminal capacitors with a reference voltage; and an output section that outputs a difference between the number of times of change in an output of the comparator, the output changing when the integrated voltage of the first terminal capacitor reaches the reference voltage, and the number of times of change in an output of the comparator, the output changing when the integrated voltage of the second terminal capacitor reaches the reference voltage, wherein the first terminal capacitor is comprised of a plurality of capacitors such that when one capacitor of the plurality of capacitors has developed the integrated voltage corresponding to the first terminal which has reached the reference voltage, at least one capacitor of the plurality of capacitors other than the one capacitor starts to develop the integrated voltage corresponding to the first terminal, and wherein the second terminal capacitor is comprised of a plurality of capacitors such that when one capacitor of the plurality of capacitors has developed the integrated voltage corresponding to the second terminal which has reached the reference voltage, at least one capacitor of the plurality of capacitors other than the one capacitor starts to develop the integrated voltage corresponding to the second terminal.
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13. A circuit for monitoring charge/discharge of a battery, comprising:
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a first terminal connected to one end of a single current detection resistor serially connected to the battery so as to detect a charge current or a discharge current of the battery; a second terminal connected to the other end of the current detection resistor; a converter that converts a terminal potential of the first terminal at which a potential of the one end of the current detection resistor appears and a terminal potential of the second terminal at which a potential of the other end of the current detection resistor appears, into currents respectively; a first terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the first terminal; a second terminal capacitor that develops an integrated voltage with supply of the current as converted by the converter from the terminal potential of the second terminal; a comparator that compares the integrated voltages developed by the first and second terminal capacitors with a reference voltage; and an output section that outputs a difference between the number of times of change in an output of the comparator, the output changing when the integrated voltage of the first terminal capacitor reaches the reference voltage, and the number of times of change in an output of the comparator, the output changing when the integrated voltage of the second terminal capacitor reaches the reference voltage, wherein the circuit is integrated into an integrated circuit.
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Specification