Battery charger for portable electronic equipment
First Claim
1. A battery charger for a portable electronic device, comprising:
- a power supply;
a power supply line connected to the power supply;
a ground line connected to the power supply;
a USB connector comprising a Vbus terminal;
a switching device connected between the power supply line and the Vbus terminal; and
a controller configured to;
perform a first detection to detect a change in a voltage at the Vbus terminal by outputting a first voltage to the Vbus terminal from a voltage output portion of the controller while the switching device is open and terminating the outputting of the first voltage, to judge whether the portable electronic device is connected to the USB connector based on a result of the first detection, wherein the first detection is performed after the terminating of the outputting of the first voltage;
turn on the switching device when the controller judges that the portable electronic device is connected to the USB connector;
perform a second detection to detect a change in the voltage at the Vbus terminal by outputting a second voltage that is different from the first voltage to the Vbus terminal and then terminating the outputting of the second voltage to and determining whether the voltage at the Vbus terminal changes from the second voltage when the controller judges that the portable electronic device is not connected to the USB connector based on the result of the first detection, and judges whether the portable electronic device is connected to the USB connector based on a result of the second detection; and
turn on the switching device when the controller judges that the portable electronic device is connected to the USB connector.
6 Assignments
0 Petitions
Accused Products
Abstract
There is offered a battery charger for a portable electronic device that has a simple structure and is capable of detecting that the portable electronic device is connected to the battery charger. A first power supply line is connected to a positive terminal (+) of a rechargeable battery, while a ground line is connected to a negative terminal (−) of the rechargeable battery. An output transistor is connected between the first power supply line and a second power supply line. The output transistor is connected to a Vbus terminal of a USB connector through the second power supply line. A controller outputs a voltage of an H level to the Vbus terminal to detect a change in a voltage at the Vbus terminal, and judges whether the portable electronic device is connected to the USB connector based on a result of the detection. The controller turns the output transistor on when the portable electronic device is judged to be connected to the USB connector.
20 Citations
21 Claims
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1. A battery charger for a portable electronic device, comprising:
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a power supply; a power supply line connected to the power supply; a ground line connected to the power supply; a USB connector comprising a Vbus terminal; a switching device connected between the power supply line and the Vbus terminal; and a controller configured to; perform a first detection to detect a change in a voltage at the Vbus terminal by outputting a first voltage to the Vbus terminal from a voltage output portion of the controller while the switching device is open and terminating the outputting of the first voltage, to judge whether the portable electronic device is connected to the USB connector based on a result of the first detection, wherein the first detection is performed after the terminating of the outputting of the first voltage; turn on the switching device when the controller judges that the portable electronic device is connected to the USB connector; perform a second detection to detect a change in the voltage at the Vbus terminal by outputting a second voltage that is different from the first voltage to the Vbus terminal and then terminating the outputting of the second voltage to and determining whether the voltage at the Vbus terminal changes from the second voltage when the controller judges that the portable electronic device is not connected to the USB connector based on the result of the first detection, and judges whether the portable electronic device is connected to the USB connector based on a result of the second detection; and turn on the switching device when the controller judges that the portable electronic device is connected to the USB connector. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A battery charging circuit, comprising:
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a power supply having a power supply line and a ground line connected to the power supply; a USB connector having a Vbus terminal and a ground terminal, the ground terminal connected to the ground line; a switching device connected between the power supply line and the Vbus terminal; and a controller that performs; a first detection while the switching device is off to detect a change in a voltage at the Vbus terminal by providing a high voltage to the Vbus terminal from a voltage output portion of the controller for a preselected time period and terminating the outputting of the high voltage and then removing the high voltage at the end of the preselected time period, wherein after the preselected period of time, the voltage output portion is placed in a high impedance state and when the Vbus changes from the high voltage to a low voltage when the voltage output portion is placed in the high impedance state the controller turns the switching device on and commences a charging procedure; and a second detection while the switching device is off to detect a change in a voltage at the Vbus terminal by providing a low voltage to the Vbus terminal from the voltage output portion of the controller for a preselected time period and terminating the outputting of the low voltage and then removing the low voltage at the end of the preselected time period, wherein after the preselected period of time the voltage output portion is placed in a high impedance state and when the Vbus changes from the low voltage to a high voltage when the voltage output portion is placed in the high impedance state the controller turns the switching device on and commences a charging procedure. - View Dependent Claims (10, 11, 12, 13, 14)
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15. A method of charging a battery of a portable electronic device by a charger having a switching device coupled between a power supply and a Vbus terminal, comprising:
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a controller applying a high voltage to the Vbus terminal while the switching device is off from a voltage output portion of the controller, the high voltage being above a threshold level; removing the first voltage from the Vbus terminal and placing the voltage output portion into a high impedance state while the switching device is off; detecting the voltage at the Vbus terminal after applying and removing the first voltage at the Vbus terminal and when the voltage at the Vbus terminal changes to a level below the threshold level the charger commences a charging procedure by switching the switching device on; applying a low voltage to the Vbus terminal while the switching device is off from the voltage output portion of the controller, the low voltage being below the threshold level; removing the second voltage from the Vbus terminal and placing the voltage output portion into a high impedance state while the switching device is off; and detecting the voltage at the Vbus terminal after applying and removing the second voltage at the Vbus terminal and when the voltage at the Vbus terminal changes to a level above the threshold level, while the switching device is off, the charger commences a charging procedure by switching the switching device on. - View Dependent Claims (16, 17)
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18. A battery charging circuit, comprising:
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a power supply line and a ground line for connection to a power supply; an output terminal having a Vbus terminal and a ground terminal, the ground terminal connected to the ground line; a switching device connected between the power supply line and the Vbus terminal; and a controller that; performs a first detection while the switching device is off to detect a change in a voltage at the Vbus terminal by outputting a first voltage to the Vbus terminal and subsequently determining whether the Vbus terminal changes from a high voltage to a low voltage; selectively performs a second detection while the switching device is off to detect a change in a voltage at the Vbus terminal by providing a low voltage to the Vbus terminal and determining whether the Vbus changes from the low voltage to the high voltage; and turns on the switching device when the controller judges that a portable electronic device is connected to the output terminal in response to one of the first and second detections. - View Dependent Claims (19, 20, 21)
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Specification