Short-circuit overcurrent protection circuit

Abstract

The utility model discloses a short-circuit overcurrent protection circuit, which comprises a power supply module, a main control module, a current detection module, a switch module and a state indication module, the main control module can carry out light warning through the state indication module when the current detection module detects that the current value reaches a first threshold value, and can cut off a lamp power supply loop through the switch module when the current detection module detects that the current value reaches a second threshold value and the duration reaches a third threshold value. The second threshold is greater than the first threshold; by means of the circuit, the delay defect of traditional fuse fusing type protection can be effectively avoided, automatic recovery can be achieved after short circuit faults are removed, meanwhile, the overload early warning function is achieved, and the safety and reliability of a lamp system are remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of electrical safety protection technology, and in particular to a short-circuit overcurrent protection circuit. Background Technology

[0002] LED lights are often damaged due to excessive current caused by short circuits. Existing short circuit protection typically uses fuses to blow the circuit and provide overcurrent protection. Some technologies use a sensing resistor to detect the output current and feed it back to the MCU for judgment. The MCU then controls the switching components to cut off the power supply circuit. While this short circuit detection structure can achieve automatic and recoverable short circuit protection, it lacks a warning function. This allows the system to remain overloaded when a short circuit occurs until the short circuit protection is triggered, by which time the LED lights may have already suffered significant damage. Therefore, there is an urgent need for a new type of short circuit overcurrent protection circuit to solve these problems. Utility Model Content

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a short-circuit overcurrent protection circuit.

[0004] The technical solution adopted by one embodiment of this utility model to solve its technical problem is: a short-circuit overcurrent protection circuit, including a power supply module, a main control module, a current detection module, a switch module and a status indication module;

[0005] The power module is connected to an external power source;

[0006] The main control module is connected to the power supply module;

[0007] The power supply terminal of the current detection module is connected to the power supply module, the input terminal is connected to the lamp power supply circuit, and the output terminal is connected to the main control module. It is used to detect the current in the lamp power supply circuit.

[0008] The power supply terminal of the switch module is connected to the power supply module, the switch terminal is connected to the lamp power supply circuit, and the control terminal is connected to the main control module.

[0009] The status indicator module is connected to both the power module and the main control module.

[0010] The main control module can issue a light warning through the status indicator module when the current detection module detects that the current value has reached the first threshold, and the main control module can cut off the power supply circuit of the lamp through the switch module when the current detection module detects that the current value has reached the second threshold and the duration has reached the third threshold. The second threshold is greater than the first threshold.

[0011] As one of the preferred embodiments of this utility model, the power supply module includes a voltage regulator chip U2, a diode D16, a resistor R1, a capacitor C135, a capacitor C2, a capacitor EC1, and a capacitor EC3. The anode of the diode D16 is connected to an external power supply. The cathode of the diode D16 is connected to a switching module, one end of capacitor C135, one end of capacitor EC1, and one end of resistor R1, respectively. The other end of resistor R1 is connected to the IN pin of the voltage regulator chip U2. The OUT pin of the voltage regulator chip U2 is connected to the main control module, the current detection module, one end of capacitor EC3, and one end of capacitor C2, respectively. The GND pin of the voltage regulator chip U2, the other end of capacitor C135, the other end of capacitor EC1, one end of capacitor EC3, and one end of capacitor C2 are connected to the ground terminal.

[0012] As one of the preferred embodiments of this utility model, the current detection module includes a Hall current sensor U1, the input terminal of the Hall current sensor U1 is connected to the lamp power supply circuit, the power supply terminal of the Hall current sensor U1 is connected to the power supply module, and the output terminal of the Hall current sensor U1 is connected to the main control module.

[0013] In one preferred embodiment of this utility model, the switching module includes a relay K1, transistors Q101-Q102, diodes D101-D102, diode D3, resistors R6-R7, resistor R101, resistor R103, and capacitor EC2. One end of resistor R6 is connected to the main control module, and the other end of resistor R6 is connected to one end of capacitor EC2, one end of resistor R103, the anode of diode D101, and the base of transistor Q102. The emitter of transistor Q102 is connected to one end of resistor R7 and the anode of diode D102. The cathode of diode D101 is connected to the anode of diode D102, the relay K1, and the base of the main control module. One end of the electrical contact K1 is connected to the negative terminal of the lamp power supply circuit. The collector of transistor Q102 is connected to the base of transistor Q101 and one end of resistor R101. The other end of resistor R101 is connected to the power module and the emitter of transistor Q101. The collector of transistor Q101 is connected to the cathode of diode D3 and one end of relay K1 coil. The other end of relay K1 coil is connected to the anode of diode D3 and the ground terminal. The other end of relay K1 contact is connected to the positive terminal of the lamp power supply circuit. The other ends of resistor R7, resistor R103, and capacitor EC2 are connected to the ground terminal.

[0014] As one of the preferred embodiments of this utility model, the status indication module includes transistors Q1-Q2, LED1-LED2, and resistors R8-R11. The base of transistor Q1 is connected to the main control module via resistor R10, the base of transistor Q2 is connected to the main control module via resistor R11, the collector of transistor Q1 is connected to the power supply module via LED1 and resistor R8, the collector of transistor Q2 is connected to the power supply module via LED2 and resistor R9, and the emitters of transistors Q1 and Q2 are connected to the ground terminal.

[0015] The beneficial effects of this utility model are as follows: A short-circuit overcurrent protection circuit includes a power supply module, a main control module, a current detection module, a switch module, and a status indicator module. The main control module can provide a light warning through the status indicator module when the current detection module detects that the current value reaches a first threshold. The main control module can also cut off the power supply circuit of the lamp through the switch module when the current detection module detects that the current value reaches a second threshold and the duration reaches a third threshold, where the second threshold is greater than the first threshold. The above circuit can effectively avoid the delay defects of traditional fuse-based protection, and can automatically recover after the short-circuit fault is cleared. It also has an overload warning function, significantly improving the safety and reliability of the lighting system. Attached Figure Description

[0016] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0017] Figure 1 This is a block diagram illustrating the principle of a short-circuit overcurrent protection circuit.

[0018] Figure 2 This is a circuit diagram of a short-circuit overcurrent protection circuit.

[0019] Figure 3 This is the circuit schematic of the power module;

[0020] Figure 4 The circuit schematic of the main control module;

[0021] Figure 5 This is the circuit schematic of the current detection module;

[0022] Figure 6 This is the circuit schematic of the switching module;

[0023] Figure 7 This is the circuit schematic of the status indicator module. Detailed Implementation

[0024] This section will describe in detail the specific embodiments of the present utility model. The preferred embodiments of the present utility model are shown in the accompanying drawings. The purpose of the drawings is to supplement the textual description with graphics, so that people can intuitively and vividly understand each technical feature and the overall technical solution of the present utility model, but they should not be construed as limiting the scope of protection of the present utility model.

[0025] In the description of this utility model, "multiple" means two or more; "greater than," "less than," and "exceeding" are understood to exclude the stated number; "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly specifying the number of indicated technical features or their sequential relationship.

[0026] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] In this utility model, unless otherwise explicitly defined, the terms "setting," "installing," and "connecting" should be interpreted broadly. For example, they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to a fixed connection, a detachable connection, or an integral molding; they can refer to a mechanical connection; they can refer to the internal connection of two components or the interaction between two components. Those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0028] Reference Figures 1 to 7 A short-circuit overcurrent protection circuit includes a power supply module 10, a main control module 20, a current detection module 30, a switch module 40, and a status indication module 50.

[0029] Power module 10 is connected to an external power source;

[0030] The main control module 20 is connected to the power supply module 10;

[0031] The power supply terminal of the current detection module 30 is connected to the power supply module 10, the input terminal is connected to the lamp power supply circuit, and the output terminal is connected to the main control module 20. It is used to detect the current in the lamp power supply circuit.

[0032] The power supply terminal of the switch module 40 is connected to the power supply module 10, the switch terminal is connected to the lamp power supply circuit, and the control terminal is connected to the main control module 20.

[0033] The status indicator module 50 is connected to the power module 10 and the main control module 20 respectively;

[0034] The main control module 20 can issue a light warning through the status indicator module 50 when the current detection module 30 detects that the current value has reached the first threshold. The main control module 20 can also cut off the power supply circuit of the lamp through the switch module 40 when the current detection module 30 detects that the current value has reached the second threshold and the duration has reached the third threshold. The second threshold is greater than the first threshold.

[0035] In this invention, the power supply module 10 converts the input voltage to provide the required operating voltage for the subsequent circuits; the current detection module 30 is connected in series in the lamp power supply circuit, which can detect the current in the lamp power supply circuit and then feed back the detected current value to the main control module 20; the switch module 40 is controlled by the main control module 20 and can conduct or cut off the path between the lamp power supply circuit and the LED lamp according to the control signal of the main control module 20; the status indication module 50 is controlled by the main control module 20 and can perform light alarm according to the control signal of the main control module 20.

[0036] Specifically, the main control module 20 is preset with a first threshold, a second threshold, and a third threshold. The first and second thresholds are current thresholds, and the third threshold is a time threshold. The second threshold is greater than the first threshold. In some possible embodiments, the second threshold is preferably set to 3-8 times the rated current, and the third threshold is preferably set to 0.1-100ms. When the current detection module 30 detects that the current value in the lamp power supply circuit is lower than the first threshold, the main control module 20 determines that the lamp power supply circuit is working normally. When the current detection module 30 detects that the current value in the lamp power supply circuit reaches the first threshold, the main control module 20 determines that an overload has occurred in the lamp power supply circuit. At this time, the main control module 20 sends a control signal to the status indicator module 50 to enable the status indicator module 50 to perform a light alarm. When the current detection module 30 detects that the current value in the lamp power supply circuit reaches the second threshold and the duration reaches the third threshold, the main control module 20 determines that a short circuit has occurred in the lamp power supply circuit. At this time, the main control module 20 sends a control signal to the switch module 40 to cut off the path between the lamp power supply circuit and the LED lamp to prevent the short circuit current from burning out the LED lamp.

[0037] Reference Figures 1-3In some embodiments, the power module 10 includes a voltage regulator chip U2, a diode D16, a resistor R1, a capacitor C135, a capacitor C2, a capacitor EC1, and a capacitor EC3. The anode of the diode D16 is connected to an external power supply, and the cathode of the diode D16 is connected to the switch module 40, one end of the capacitor C135, one end of the capacitor EC1, and one end of the resistor R1. The other end of the resistor R1 is connected to the IN pin of the voltage regulator chip U2, and the OUT pin of the voltage regulator chip U2 is connected to the main control module 20, the current detection module 30, one end of the capacitor EC3, and one end of the capacitor C2. The GND pin of the voltage regulator chip U2, the other end of the capacitor C135, the other end of the capacitor EC1, one end of the capacitor EC3, and one end of the capacitor C2 are connected to the ground terminal. The voltage regulator chip U2 can step down the input voltage and stably output a 3.3V voltage, thereby supplying power to the main control module 20, the current detection module 30, and the status indicator module 50.

[0038] Reference Figures 1-2 and Figure 4 In some embodiments, the current detection module 30 includes a Hall current sensor U1, the input terminal of which is connected to the lamp power supply circuit, the power supply terminal of which is connected to the power module 10, and the output terminal of which is connected to the main control module 20. Of course, a precision resistor can also be set in the current detection module 30 to achieve more accurate current detection.

[0039] Reference Figures 1-2 and Figure 6In some embodiments, the switch module 40 includes a relay K1 (open when energized, closed when de-energized), transistors Q101-Q102, diodes D101-D102, diode D3, resistors R6-R7, resistor R101, resistor R103, and capacitor EC2. One end of resistor R6 is connected to the main control module 20, and the other end of resistor R6 is connected to one end of capacitor EC2, one end of resistor R103, the anode of diode D101, and the base of transistor Q102. The emitter of transistor Q102 is connected to one end of resistor R7 and the anode of diode D102. The cathode of diode D101 is connected to the anode of diode D102, one end of the contact of relay K1, and the negative terminal of the lamp power supply circuit. The collector of transistor Q102 is connected to the base of transistor Q101 and one end of resistor R101. The other end of 101 is connected to the power module 10 and the emitter of transistor Q101. The collector of transistor Q101 is connected to the cathode of diode D3 and one end of the coil of relay K1. The other end of the coil of relay K1 is connected to the anode of diode D3 and the ground terminal. The other end of the relay K1 contact is connected to the positive terminal of the lamp power supply circuit. The other end of resistor R7, the other end of resistor R103, and the other end of capacitor EC2 are connected to the ground terminal. Specifically, the main control module 20 controls transistor Q102 to enter the conduction state through pin 5, pulls down the base voltage of transistor Q101, so that the emitter and collector of transistor Q101 are turned on. The power module 20 supplies power to the coil of relay K1. After the coil of relay K1 is energized, the contacts of relay K1 are opened, realizing the disconnection of the path between the lamp power supply circuit and the LED lamp.

[0040] Reference Figures 1-2 and Figure 7 In some embodiments, the status indication module 50 includes transistors Q1-Q2, LED1-LED2, and resistors R8-R11. The base of transistor Q1 is connected to the main control module 20 via resistor R10, the base of transistor Q2 is connected to the main control module 20 via resistor R11, the collector of transistor Q1 is connected to the power supply module 10 via LED1 and resistor R8, the collector of transistor Q2 is connected to the power supply module 10 via LED2 and resistor R9, and the emitters of transistors Q1 and Q2 are connected to the ground terminal. Specifically, pins 7 and 8 of the main control module 20 respectively transmit corresponding signals to control the on / off state of transistors Q1 and Q2, thereby controlling LED1-LED2 and indicating the overload state.

[0041] The advantages of this invention are: the circuit described above effectively avoids the delay defects of traditional fuse-based protection, automatically recovers after a short-circuit fault is cleared, and has an overload warning function, significantly improving the safety and reliability of the lighting system.

[0042] Of course, this utility model is not limited to the above-described embodiments. Those skilled in the art can make equivalent modifications or substitutions without departing from the spirit of this utility model. All such equivalent modifications and substitutions are included within the scope defined by the claims of this application.

Claims

1. A short circuit overcurrent protection circuit, characterized by: It includes a power supply module (10), a main control module (20), a current detection module (30), a switch module (40), and a status indicator module (50); The power module (10) is connected to an external power source; The main control module (20) is connected to the power supply module (10); The power supply terminal of the current detection module (30) is connected to the power supply module (10), the input terminal is connected to the lamp power supply circuit, and the output terminal is connected to the main control module (20), and is used to detect the current in the lamp power supply circuit; The power supply terminal of the switch module (40) is connected to the power supply module (10), the switch terminal is connected to the lamp power supply circuit, and the control terminal is connected to the main control module (20). The status indicator module (50) is connected to the power module (10) and the main control module (20) respectively; The main control module (20) can issue a light warning through the status indicator module (50) when the current detection module (30) detects that the current value reaches the first threshold, and the main control module (20) can cut off the power supply circuit of the lamp through the switch module (40) when the current detection module (30) detects that the current value reaches the second threshold and the duration reaches the third threshold, wherein the second threshold is greater than the first threshold.

2. The short circuit over current protection circuit according to claim 1, characterized in that: The power module (10) includes a voltage regulator chip U2, a diode D16, a resistor R1, a capacitor C135, a capacitor C2, a capacitor EC1, and a capacitor EC3. The anode of the diode D16 is connected to an external power supply. The cathode of the diode D16 is connected to the switch module (40), one end of the capacitor C135, one end of the capacitor EC1, and one end of the resistor R1. The other end of the resistor R1 is connected to the IN pin of the voltage regulator chip U2. The OUT pin of the voltage regulator chip U2 is connected to the main control module (20), the current detection module (30), one end of the capacitor EC3, and one end of the capacitor C2. The GND pin of the voltage regulator chip U2, the other end of the capacitor C135, the other end of the capacitor EC1, one end of the capacitor EC3, and one end of the capacitor C2 are connected to the ground terminal.

3. The short circuit over current protection circuit of claim 1, wherein: The current detection module (30) includes a Hall current sensor U1. The input terminal of the Hall current sensor U1 is connected to the lamp power supply circuit, the power supply terminal of the Hall current sensor U1 is connected to the power supply module (10), and the output terminal of the Hall current sensor U1 is connected to the main control module (20).

4. The short circuit over current protection circuit of claim 1, wherein: The switching module (40) includes a relay K1, transistors Q101-Q102, diodes D101-D102, diode D3, resistors R6-R7, resistors R101, resistor R103, and capacitor EC2. One end of resistor R6 is connected to the main control module (20), and the other end of resistor R6 is connected to one end of capacitor EC2, one end of resistor R103, the anode of diode D101, and the base of transistor Q102. The emitter of transistor Q102 is connected to one end of resistor R7 and the anode of diode D102. The cathode of diode D101 is connected to the anode of diode D102, one end of the contact of relay K1, and the negative terminal of the lamp power supply circuit. The collector of 102 is connected to the base of transistor Q101 and one end of resistor R101, respectively. The other end of resistor R101 is connected to the power module (10) and the emitter of transistor Q101, respectively. The collector of transistor Q101 is connected to the cathode of diode D3 and one end of relay K1 coil, respectively. The other end of relay K1 coil is connected to the anode of diode D3 and the ground terminal, respectively. The other end of relay K1 contact is connected to the positive terminal of the lamp power supply circuit. The other end of resistor R7, the other end of resistor R103 and the other end of capacitor EC2 are connected to the ground terminal.

5. The short circuit over current protection circuit of claim 1, wherein: The status indication module (50) includes transistors Q1-Q2, LED1-LED2, and resistors R8-R11. The base of transistor Q1 is connected to the main control module (20) via resistor R10, the base of transistor Q2 is connected to the main control module (20) via resistor R11, the collector of transistor Q1 is connected to the power supply module (10) via LED1 and resistor R8, the collector of transistor Q2 is connected to the power supply module (10) via LED2 and resistor R9, and the emitters of transistors Q1 and Q2 are connected to the ground terminal.

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