Charging circuit for secondary battery
First Claim
1. A charging circuit for charging a secondary battery, comprising;
- a constant-current circuit that outputs, to the secondary battery, one of first and second constant currents in response to an input control signal;
a constant-voltage circuit that charges the secondary battery by applying a predetermined constant voltage thereto;
a battery voltage detection circuit that detects and outputs a battery voltage of the secondary battery;
a charge current detection circuit that outputs a predetermined charge completion signal when a predetermined current flows to said secondary battery; and
a charge control circuit that stops operations of said constant-current circuit and said constant-voltage circuit when the charge completion signal is input, wherein, when the battery voltage of the secondary battery is lower than a predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause said constant-current circuit to output the first constant current, and when the battery voltage of the secondary battery is equal to or greater than the predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause the constant-current circuit to output the second constant current that is greater than the first constant current.
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Accused Products
Abstract
A charging circuit for a secondary battery includes a constant-voltage circuit part outputting one of a plurality of predetermined constant voltages and charges the secondary battery by applying the constant voltage thereto, a detection circuit part detecting a battery voltage of the secondary battery, and a control circuit part controlling the selection of the constant-voltage in response to the detected battery voltage. Another charging circuit includes a constant-current circuit part outputting, to the secondary battery, one of two predetermined constant currents, a constant-voltage circuit part charging the secondary battery by applying a predetermined constant voltage thereto, a battery voltage detection circuit part detecting a battery voltage of the secondary battery, a charge current detection circuit part outputting a predetermined charge completion signal, and a charge control circuit part stopping operations of the constant-current circuit part and constant-voltage circuit part when receiving the charge completion signal.
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Citations
19 Claims
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1. A charging circuit for charging a secondary battery, comprising;
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a constant-current circuit that outputs, to the secondary battery, one of first and second constant currents in response to an input control signal;
a constant-voltage circuit that charges the secondary battery by applying a predetermined constant voltage thereto;
a battery voltage detection circuit that detects and outputs a battery voltage of the secondary battery;
a charge current detection circuit that outputs a predetermined charge completion signal when a predetermined current flows to said secondary battery; and
a charge control circuit that stops operations of said constant-current circuit and said constant-voltage circuit when the charge completion signal is input, wherein, when the battery voltage of the secondary battery is lower than a predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause said constant-current circuit to output the first constant current, and when the battery voltage of the secondary battery is equal to or greater than the predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause the constant-current circuit to output the second constant current that is greater than the first constant current. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A charging circuit for charging a secondary battery, comprising:
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a constant-current circuit that outputs, to the secondary battery, one of first and second constant currents in response to an input control signal;
a constant-voltage circuit that charges the secondary battery by applying a predetermined constant voltage thereto;
a battery voltage detection circuit that detects and outputs a battery voltage of the secondary battery;
a circuit that outputs a predetermined charge completion signal; and
a charge control circuit that stops operations of said constant-current circuit and said constant-voltage circuit when the charge completion signal is input, wherein, when the battery voltage of the secondary battery is lower than a predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause said constant-current circuit to output the first constant current, and when the battery voltage of the secondary battery is equal to or greater than the predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause the constant-current circuit to output the second constant current that is greater than the first constant current. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A charging circuit for charging a secondary battery using a constant-current/constant voltage charging method, comprising:
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a constant-voltage circuit configured to charge the secondary battery in a constant-voltage mode;
a constant-current circuit configured to charge the secondary battery in a constant current mode, wherein, when a battery voltage of the secondary battery is lower than a predetermined voltage, the constant-current circuit outputs a first constant current, and when the battery voltage of the secondary battery is equal to or greater than a predetermined voltage, the constant-current circuit outputs a second constant current that is greater than the first constant current.
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16. A charging circuit for charging a secondary battery, comprising;
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a constant-current circuit that outputs, to the secondary battery, one of first and second constant currents in response to an input control signal;
a constant-voltage circuit that charges the secondary battery by applying a predetermined constant voltage thereto;
a battery voltage detection circuit that detects a battery voltage of the secondary battery, and outputs a signal representative of a battery voltage of the secondary battery;
a charge current detection circuit that outputs a predetermined charge completion signal when a predetermined current flows to said secondary battery; and
a charge control circuit that stops operations of said constant-current circuit and said constant-voltage circuit when the charge completion signal is input, wherein, when the battery voltage of the secondary battery is lower than a predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause said constant-current circuit to output the first constant current, and when the battery voltage of the secondary battery is equal to or greater than the predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause the constant-current circuit to output the second constant current that is greater than the first constant current. - View Dependent Claims (17)
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18. A charging circuit for charging a secondary battery, comprising:
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a constant-current circuit that outputs, to the secondary battery, one of first and second constant currents in response to an input control signal;
a constant-voltage circuit that charges the secondary battery by applying a predetermined constant voltage thereto;
a battery voltage detection circuit that detects a battery voltage of the secondary battery, and outputs a signal representative of a battery voltage of the secondary battery;
a charge completion circuit that outputs a predetermined charge completion signal; and
a charge control circuit that stops operations of said constant-current circuit and said constant-voltage circuit when the charge completion signal is input, wherein, when the battery voltage of the secondary battery is lower than a predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause said constant-current circuit to output the first constant current, and when the battery voltage of the secondary battery is equal to or greater than the predetermined voltage, said charge control circuit outputs, to said constant-current circuit, the control signal to cause the constant-current circuit to output the second constant current that is greater than the first constant current. - View Dependent Claims (19)
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Specification