CIRCUIT PROTECTION APPARATUS

• US 20140218200A1
• Filed: 02/02/2013
• Published: 08/07/2014
• Est. Priority Date: 02/02/2013
• Status: Active Grant

• Current Assignee: Chun-Fu Lin, Shu-Ling Chen
• Original Assignee: Chun-Fu Lin, Shu-Ling Chen
• Inventors: CHEN, SHU-LING
• Granted Patent: US 9,112,352 B2
• Time in Patent Office: Days
• US Class Current: 340/644
• CPC Class Codes: H02H 3/04 with warning or supervision in addition to disconnection, e.g. for indicating that protective apparatus has functioned watching of pilot wires H02H1/0084; protection of protective arrangements H02H7/008; indication of the state of electronic switches H03K17/18
• CPC Class Codes: H02H 3/087 for dc applications
• CPC Class Codes: H02J 7/0036 using connection detecting circuits H02J7/0034 takes precedence

Abstract

A circuit protection apparatus is disclosed. A peripheral interface includes a first power node and a second power node. The circuit protection apparatus includes an auxiliary power supply circuit, a power converter, a first switch, a second switch, a power switch circuit, a warning circuit, and a controller. When a load is plugged to the peripheral interface, the first switch turns on, and the controller is enabled and outputs a control signal, so as to drive the power converter to output power. When the current between input terminal and output terminal of the power switch circuit is larger than a predetermined current, the controller receives the error flag logical voltage outputted by the power switch circuit, cuts off the current between input terminal and output terminal of the power switch circuit, and stops the operations of the power converter.

Claims

1. A circuit protection apparatus, for controlling a peripheral interface, wherein the peripheral interface includes a first power node and a second power node, and the circuit protection apparatus comprises:

an auxiliary power supply circuit, including a first terminal and a second terminal, wherein the first terminal of the auxiliary power supply circuit is coupled to a power voltage, and the second terminal of the auxiliary power supply circuit is coupled to the first power node;

a power converter, including an input terminal and an output terminal, wherein the output terminal of the power converter is coupled to the second terminal of the auxiliary power supply circuit, and the input terminal of the power converter receives a control signal for adjusting a voltage of the output terminal of the power converter according to the control signal;

a first switch, including a first terminal, a second terminal, and a control terminal, wherein the second terminal of the first switch is coupled to a common voltage, and the control terminal of the first switch is coupled to the second power node;

a second switch, including a first terminal, a second terminal, and a control terminal, wherein the second terminal of the second switch is coupled to the common voltage, and the first terminal of the second switch is coupled to the second power node; and

a controller, including a first control terminal, a second control terminal, an enable terminal, and a detection terminal, wherein the first control terminal of the controller is coupled to the input terminal of the power converter, the second control terminal of the controller is coupled to the control terminal of the second switch, the enable terminal of the controller is coupled to the first terminal of the first switch, and the detection terminal of the controller is coupled to the second power node;

wherein when a load is plugged to the peripheral interface and makes the first power node and the second power node be electrically connected with each other through the load, the second terminal of the auxiliary power supply circuit provides the power voltage to the control terminal of the first switch through the load, so that the first switch turns on and the enable terminal of the controller receives the common voltage;

wherein after the enable terminal of the controller receives the common voltage, the controller is enabled, the first control terminal of the controller outputs the control signal for driving the output terminal of the power converter to output a power, the controller controls the second switch to turn on by using the second control terminal of the controller, and the controller continuously detects a voltage of the second power node by using the detection terminal;

wherein when the controller detects that the voltage of the second power node is lower than a predetermined voltage, the first control terminal of the controller stops outputting the control signal, and the controller enters into a power saving mode.

2. The circuit protection apparatus according to claim 1, further comprising:

a power switch circuit, including an input terminal, an output terminal, a warning terminal, and an enable terminal, wherein the input terminal of the power switch circuit is coupled to the output terminal of the power converter, and the output terminal of the power switch circuit is coupled to the first power node;

a warning circuit, coupled to the common voltage;

wherein the controller further includes at least one warning control terminal, an enable control terminal, and an abnormity warning terminal, wherein the at least one warning control terminal of the controller is coupled to the warning circuit, the enable control terminal of the controller is coupled to the enable terminal of the power switch circuit, and the abnormity warning terminal of the controller is coupled to the warning terminal of the power switch circuit; and

wherein when the load is plugged to the peripheral interface and makes the first power node and the second power node electrically connected with each other through the load, the controller controls the power converter for outputting a power voltage, and the enable control terminal of the controller outputs an enable signal, wherein when the enable terminal of the power switch circuit receives the enable signal, the input terminal of the power switch circuit and the output terminal of the power switch circuit are conductive;

wherein when the load is too large and makes the first power node and the second power node short-circuited, thus makes currents of the input terminal and the output terminal of the power switch circuit larger than a predetermined current, the warning terminal of the power switch circuit outputs an error flag logical voltage;

when the abnormity warning terminal of the controller receives the error flag logical voltage, the controller turns off the power converter through the first control terminal, and the controller turns off the power switch circuit through the enable control terminal, so as to cut off the input terminal and the output terminal of the power switch circuit, and the controller turns on the warning circuit through the at least one warning control terminal for warning users.

3. The circuit protection apparatus according to claim 2, wherein when the abnormity warning terminal of the controller receives the error flag logical voltage, the controller turns off the second switch through the second control terminal, and the controller makes the warning circuit work by using the at least one warning control terminal for warning the users;

and

wherein when the load is removed and the detection terminal of the controller detects that the voltage is lower than the predetermined voltage, the controller enters a standby mode, controls the second switch to turn off through the second control terminal of the controller, and the enable control terminal of the controller outputs the enable signal for making the input terminal of the power switch circuit and the output terminal of the power switch circuit short-circuited.

4. The circuit protection apparatus according to claim 1, further comprising:

a first impedance component, including a first terminal and a second terminal, wherein the first terminal of the first impedance component is coupled to the second power node, and the second terminal of the first impedance component is coupled to the common voltage.

5. The circuit protection apparatus according to claim 1, further comprising:

a second impedance component, including a first terminal and a second terminal, wherein the first terminal of the second impedance component is coupled to the second power node, and the second terminal of the second impedance component is coupled to the first terminal of the second switch.

6. The circuit protection apparatus according to claim 1, further comprising:

a third impedance component, including a first terminal and a second terminal, wherein the first terminal of the third impedance component is coupled to the control terminal of the second switch, and the second terminal of the third impedance component is coupled to the common voltage.

7. The circuit protection apparatus according to claim 1, wherein the first switch further includes:

a first metal-oxide semiconductor field-effect transistor, including a gate node, a first node, and a second node, wherein the gate node of the first metal-oxide semiconductor field-effect transistor is coupled to the control terminal of the first switch, the first node of the first metal-oxide semiconductor field-effect transistor is coupled to the first terminal of the first switch, and the second node of the first metal-oxide semiconductor field-effect transistor is coupled to the second terminal of the first switch.

8. The circuit protection apparatus according to claim 1, wherein the first switch further includes:

a first bipolar transistor, including a base node, a collector node, and an emitter node, wherein the base node of the first bipolar transistor is coupled to the control terminal of the first switch, the collector node of the first bipolar transistor is coupled to the first terminal of the first switch, and the emitter node of the first bipolar transistor is coupled to the second terminal of the first switch.

9. The circuit protection apparatus according to claim 1, wherein the second switch further includes:

a second metal-oxide semiconductor field-effect transistor, including a gate node, a first node, and a second node, wherein the gate node of the second metal-oxide semiconductor field-effect transistor is coupled to the control terminal of the second switch, the first node of the second metal-oxide semiconductor field-effect transistor is coupled to the first terminal of the second switch, and the second node of the second metal-oxide semiconductor field-effect transistor is coupled to the second terminal of the second switch.

10. The circuit protection apparatus according to claim 1, wherein the second switch further includes:

a second bipolar transistor, including a base node, a collector node, and an emitter node, wherein the base node of the second bipolar transistor is coupled to the control terminal of the second switch, the collector node of the second bipolar transistor is coupled to the first terminal of the second switch, and the emitter node of the second bipolar transistor is coupled to the second terminal of the second switch.

11. The circuit protection apparatus according to claim 1, wherein the auxiliary power supply circuit further includes:

a fourth impedance component, including a first terminal and a second terminal, wherein the first terminal of the fourth impedance component is coupled to the first terminal of the auxiliary power supply circuit, and the second terminal of the fourth impedance component is coupled to the second terminal of the auxiliary power supply circuit.

12. The circuit protection apparatus according to claim 2, wherein the warning circuit includes at least one light emitting diode, for emitting lights to warn the users.

13. The circuit protection apparatus according to claim 2, wherein the warning circuit includes at lease one speaker, for generating sounds to warn the users.

14. The circuit protection apparatus according to claim 12, wherein the warning circuit includes at least one speaker, for generating sounds to warn the users.

15. The circuit protection apparatus according to claim 2, wherein the power switch circuit further includes:

a first resistor, including a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the input terminal of the power switch circuit, and the second terminal of the first resistor is coupled to the output terminal of the power switch circuit;

a second resistor, including a first terminal and a second terminal, wherein the first terminal of the second resistor is coupled to the input terminal of the power switch circuit;

a third resistor, including a first terminal and a second terminal, wherein the second terminal of the third resistor is coupled to the output terminal of the power switch circuit;

a first amplifier, including a non-inverting input terminal, an inverting input terminal, and an output terminal, wherein the non-inverting input terminal of the first amplifier is coupled to the second terminal of the second resistor, and the inverting input terminal of the first amplifier is coupled to the second terminal of the third resistor;

a third bipolar transistor, including a base node, a collector node, and an emitter node, wherein the base node of the third bipolar transistor is coupled to the output terminal of the first amplifier, and the collector node of the third bipolar transistor is coupled to the non-inverting input terminal of the first amplifier;

a fourth resistor, including a first terminal and a second terminal, wherein the first terminal of the fourth resistor is coupled to the emitter node of the third bipolar transistor, and the second terminal of the fourth resistor is coupled to the common voltage; and

a second amplifier, including a non-inverting input terminal, an inverting input terminal, and an output terminal, wherein the non-inverting input terminal of the second amplifier is coupled to a reference voltage, the inverting input terminal of the second amplifier is coupled to the first terminal of the fourth resistor, and the output terminal of the second amplifier outputs the error flag logical voltage.

16. The circuit protection apparatus according to claim 2, wherein the power switching circuit further includes:

a first resistor, including a first terminal and a second terminal, wherein the first terminal of the first resistor is coupled to the input terminal of the power switch circuit, and the second terminal of the first resistor is coupled to the output terminal of the power switch circuit;

a second resistor, including a first terminal and a second terminal, wherein the first terminal of the second resistor is coupled to the input terminal of the power switch circuit;

a third resistor, including a first terminal and a second terminal, wherein the second terminal of the third resistor is coupled to the output terminal of the power switch circuit;

a first amplifier, including a non-inverting input terminal, an inverting input terminal, and an output terminal, wherein the non-inverting input terminal of the first amplifier is coupled to the second terminal of the second resistor, the inverting input terminal of the first amplifier is coupled to the second terminal of the third resistor, and the output terminal of the first amplifier outputs the error flag logical voltage; and

a fourth resistor, including a first terminal and a second terminal, wherein the first terminal of the fourth resistor is coupled to the output terminal of the first amplifier, and the second terminal of the fourth resistor is coupled to the common voltage.