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US 2011/0235219 A1Published application
Protecting device
AssigneesHONG FU JIN PRECISION INDUSTRY (ShenZhen) CO., LTD., Hon Hai Precision Industry Co., Ltd.
InventorYONG-ZHAO HUANG
Life of this patent
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Abstract
A protecting device includes a power plug, a switch circuit, and a power supply circuit. The switch circuit is connected to the power plug. The power supply circuit is connected to the switch circuit and the power plug. When the temperature of the protecting device is higher than a predetermined temperature, a voltage at a node between a thermo-sensor and a variable resistor is higher than a turn-on voltage of a second electrical switch to turn on the second electrical switch, a first electrical switch is turned off, the power supply circuit is disconnected from the power plug to stop the electronic device from working.
Claims10
A protecting device comprising:
- a power plug to receive an alternating current (AC) voltage, the power plug comprising a first terminal and a second terminal;
- a power supply circuit connected to the power plug to receive the AC voltage to power the electronic device;
- a switch circuit connected to the power supply circuit and the power plug, the switch circuit comprising:
- a rectifier to convert the AC voltage from the power plug into a direct current (DC) voltage, the rectifier comprising a first input terminal connected to the first terminal of the power plug, a second input terminal connected to the second terminal of the power plug, and first and second output terminals;
- a first electrical switch comprising a first terminal connected to the first terminal of the power plug via the power supply circuit, a second terminal connected to the second terminal of the power plug, and a control terminal;
- a second electrical switch comprising a first terminal connected to the control terminal of the first electrical switch via a first resistor and the first output terminal of the rectifier via a second resistor, a second terminal connected to the second output terminal of the rectifier, and a control terminal;
- a thermo-sensor to sense a temperature of the electronic device to change a resistance thereof;
- a variable resistor connected to the thermo-sensor in series between the first and second output terminal of the rectifier, wherein a node between the variable resistor and the thermo-sensor connected to the control terminal of the second electrical switch;
- wherein when the temperature of the electronic device is higher than a predetermined temperature, a voltage at the node between the thermo-sensor and the variable resistor is higher than a turn-on voltage of the second electrical switch to turn on the second electrical switch, the first electrical switch is turned off, the power supply circuit is disconnected from the power plug to stop the electronic device.
6 more elements
A protecting device comprising:
- a power plug to receive a direct current (DC) voltage, the power plug comprising a first terminal and a second terminal;
- a power supply circuit connected to the power plug to receive DC voltage to power the electronic device;
- a switch circuit connected to the power supply circuit and the power plug, the switch circuit comprising:
- a first electrical switch comprising a first terminal connected to the first terminal of the power plug via the power supply circuit, a second terminal connected to the second terminal of the power plug, and a control terminal;
- a second electrical switch comprising a first terminal connected to the control terminal of the first electrical switch via a first resistor and the first terminal of the power plug via a second resistor, a second terminal connected to the second terminal of the power plug, and a control terminal;
- a thermo-sensor to sense a temperature of the electronic device to change a resistance thereof;
- a variable resistor connected to the thermo-sensor in series between the first terminal and second terminal of the second electrical switch, wherein a node between the variable resistor and the thermo-sensor connected to the control terminal of the second electrical switch;
- wherein when the temperature of the electronic device is higher than a predetermined temperature, a voltage at the node between the thermo-sensor and the variable resistor is higher than a turn-on voltage of the second electrical switch to turn on the second electrical switch, the first electrical switch is turned off, the power supply circuit is disconnected from the power plug to stop powering the electronic device.
5 more elements
Dependencies are inferred from the claim text.