A detection and protection device with overvoltage and overcurrent protection functions

Abstract

This utility model relates to the field of electrical control technology, specifically a detection and protection device with overvoltage and overcurrent protection functions. It includes a power input module, an overcurrent protection module, a rectifier module, a control trigger module, and a chip control module. The power input module connects to an AC power source via L and N pins, and a varistor MOV1 is connected in parallel to achieve overvoltage protection. The overcurrent protection module uses a coil and a trip switch S1 to trigger S1 to trip and cut off power during overcurrent. The rectifier module uses an M7 diode to form a rectifier bridge, converting AC to DC. The control trigger module uses a silicon controlled rectifier (SCR1) for rapid switching, combined with an RC circuit for stable triggering. The chip control module uses an APX823-26W5G-7 chip to detect signals and output control commands. This device has a response time of ≤20ms, provides dual overvoltage / overcurrent protection with automatic recovery, and is suitable for the safety protection of motors and other equipment.

Description

Technical Field

[0001] This utility model relates to the field of electrical control technology, and in particular to a detection and protection device with overvoltage and overcurrent protection functions. Background Technology

[0002] Overvoltage and overcurrent are common anomalies in the operation of electrical systems. These conditions can easily damage equipment, affect its normal operation, and even cause safety accidents. Existing protection circuits have many shortcomings, such as slow response speed, typically requiring more than 100ms to react, making it difficult to quickly respond to sudden faults in the circuit; moreover, their protection functions are limited, with many protection circuits only providing overcurrent or overvoltage protection. For example, some protection circuits on the market use current transformers to detect overcurrent signals and trigger thyristors through comparators, but lack effective integration of overvoltage protection, failing to comprehensively ensure the safety of electrical equipment; in addition, existing protection devices also suffer from problems such as lack of automatic recovery and low reliability, requiring manual reset operations, which not only increases maintenance costs but may also cause secondary damage to equipment due to untimely resets.

[0003] Therefore, developing a protection solution that is fast-responding, comprehensive in protection functions, moderately priced, and highly reliable has become an urgent problem to be solved in the field of power electronics technology and motor control. Utility Model Content

[0004] The purpose of this invention is to overcome the problems of the prior art and provide a detection and protection device with overvoltage and overcurrent protection functions, so as to solve the technical problems of slow response speed, single protection function, inability to automatically recover and low reliability of existing protection circuits, as well as the lack of effective integration of overvoltage protection.

[0005] The above objectives are achieved through the following technical solutions: A detection and protection device with overvoltage and overcurrent protection functions includes a power input module, an overcurrent protection module, a rectification module, a control trigger module, and a chip control module; The power input module is connected to an AC power source through terminal L and terminal N; The rectifier module is connected to the power input module and is used to convert AC power into DC power. The overcurrent protection module is connected in series between the power input module and the rectifier module, and is used to detect overcurrent and trigger power-off protection. The chip control module is connected to the rectifier module and the control trigger module, and is used to process the detection signal and output control commands. The control trigger module is connected to the rectifier module and the chip control module, and is used to receive control signals and perform circuit switching operations.

[0006] Furthermore, in the power input module, a varistor is connected in parallel between the terminal L and the terminal N. The varistor is of model 07D561K and is used to implement overvoltage protection.

[0007] Furthermore, the overcurrent protection module includes a coil and a trip switch connected to each other; the coil is connected in series in the main circuit between the power input module and the rectifier module, the trip switch works in conjunction with the coil, and the trip switch is marked with a "Trip" mark to trigger the trip circuit to disconnect in case of overcurrent.

[0008] Further, the rectifier module comprises a rectifier bridge consisting of a first diode, a second diode, a third diode, and a fourth diode; the cathodes of the first diode and the second diode are connected as the first terminal of the bridge rectifier circuit, the anodes of the second diode and the fourth diode are connected as the second terminal of the bridge rectifier circuit, the anodes of the fourth diode and the third diode are connected as the third terminal of the bridge rectifier circuit, and the cathodes of the third diode and the first diode are connected as the fourth terminal of the bridge rectifier circuit; the first terminal of the rectifier bridge is connected to the control trigger module and the chip control module, the second terminal of the rectifier bridge is connected to the terminal L, the third terminal of the rectifier bridge is connected to the control trigger module and grounded, and the fourth terminal of the rectifier bridge is connected to the trip switch.

[0009] Furthermore, the control trigger module includes a thyristor and a filter delay circuit composed of a first capacitor and a fourth resistor. The anode of the thyristor is connected to the first end of the rectifier bridge, the cathode of the thyristor is grounded, and the gate of the thyristor is connected to the filter delay circuit and the chip control module.

[0010] Furthermore, the control trigger module also includes a voltage divider circuit consisting of a first resistor, a second resistor, and a third resistor connected in series. One end of the voltage divider circuit is connected to the anode of the thyristor and the first end of the rectifier bridge, and the other end is connected to the chip control module.

[0011] Furthermore, the control trigger module also includes a current-limiting resistor, one end of which is connected to the OUT pin of the chip control module, and the other end is connected to the gate of the thyristor.

[0012] Furthermore, the chip control module includes a chip, and the VDD+ pin of the chip is connected to the first end of the rectifier bridge through a fifth resistor and a second capacitor.

[0013] Furthermore, the chip model is APX823-26W5G-7.

[0014] This utility model provides a detection and protection device with overvoltage and overcurrent protection functions. Firstly, it integrates overvoltage and overcurrent protection functions. Overvoltage is handled by a varistor MOV1, and overcurrent is handled by a coil and trip switch S1, comprehensively protecting electrical equipment from damage caused by abnormal voltage and current. Secondly, it features fast response and high reliability. Utilizing a varistor and electromagnetic trip mechanism, combined with chip control and thyristor triggering, the protection action response speed is ≤20ms, far superior to the over 100ms delay of traditional protection circuits, allowing for rapid disconnection of faulty circuits. Thirdly, it has automatic recovery capability; after fault resolution, normal operation can be restored without manual intervention, reducing maintenance costs and operational inconvenience. Furthermore, the overall structure is rationally designed, the component models used are clearly defined and easily obtainable, and the cost is moderate. It can be widely applied to various electrical equipment such as industrial motors and household appliances, demonstrating broad applicability and strong practicality. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of a detection and protection device with overvoltage and overcurrent protection functions according to the present invention; Figure 2 This is a circuit diagram of a detection and protection device with overvoltage and overcurrent protection functions as described in this utility model. Detailed Implementation

[0016] The present invention will be further described in detail below with reference to the figures and embodiments.

[0017] like Figure 1 As shown, a detection and protection device with overvoltage and overcurrent protection functions includes a power input module, an overcurrent protection module, a rectification module, a control trigger module, and a chip control module. The power input module is connected to an AC power source through terminal L and terminal N; The rectifier module is connected to the power input module and is used to convert AC power into DC power. The overcurrent protection module is connected in series between the power input module and the rectifier module, and is used to detect overcurrent and trigger power-off protection. The chip control module is connected to the rectifier module and the control trigger module, and is used to process the detection signal and output control commands. The control trigger module is connected to the rectifier module and the chip control module, and is used to receive control signals and perform circuit switching operations.

[0018] In the power input module described in this embodiment, a varistor MOV1 is connected in parallel between the terminal L and the terminal N. The varistor MOV1 is of model 07D561K and is used to implement overvoltage protection.

[0019] Working principle: Under normal voltage, the resistance of MOV1 is extremely high (approximately open circuit), which does not affect the operation of the circuit; when the voltage between L and N exceeds the threshold (determined by the MOV1 model), the resistance of MOV1 decreases instantaneously, dissipating the overvoltage energy through itself or releasing it to ground, thus preventing high voltage from being transmitted to subsequent circuits.

[0020] like Figure 2 As shown, the overcurrent protection module in this embodiment includes a coil and a trip switch S1 connected to each other; the coil is connected in series in the main circuit between the power input module and the rectifier module, the trip switch S1 works in conjunction with the coil, and the trip switch S1 is marked with a "Trip" label, which is used to trigger the trip to disconnect the circuit when there is an overcurrent.

[0021] Working principle: When normal current flows through the coil, the magnetic field generated by the coil is weak, and S1 remains closed. When an overcurrent occurs in the circuit, the coil current increases, the magnetic field strength rises sharply, triggering S1 to trip. S1 disconnects the main circuit, cuts off the power input, and achieves overcurrent protection. After the fault is cleared, the coil magnetic field weakens, and S1 can automatically reset and close without manual operation.

[0022] The rectifier module consists of a rectifier bridge composed of a first diode D1, a second diode D2, a third diode D3, and a fourth diode D4. The cathodes of the first diode D1 and the second diode D2 are connected as the first terminal of the bridge rectifier circuit; the anode of the second diode D2 and the cathode of the fourth diode D4 are connected as the second terminal; the anode of the fourth diode D4 and the anode of the third diode D3 are connected as the third terminal; and the cathode of the third diode D3 and the anode of the first diode D1 are connected as the fourth terminal. The first terminal of the rectifier bridge is connected to the control trigger module and the chip control module; the second terminal is connected to the terminal L; the third terminal is connected to the control trigger module and grounded; and the fourth terminal is connected to the trip switch S1. The first diode D1, the second diode D2, the third diode D3, and the fourth diode D4 are of type M7.

[0023] Working principle: During the positive half-cycle of AC circuit: the current flows from terminal L through D1 → subsequent circuit → D3 → terminal N, forming a loop; Negative half-cycle of AC circuit: Current flows from terminal N through D2 → subsequent circuit → D4 → terminal L, forming a loop; Full-wave rectification converts alternating current into direct current with a constant direction, providing a stable DC signal for subsequent modules.

[0024] The control trigger module includes a silicon controlled rectifier (SCR1) and a filter delay circuit consisting of a first capacitor C1 and a fourth resistor R4. The anode of the SCR1 is connected to the first end of the rectifier bridge, the cathode of the SCR1 is grounded, and the gate (G) of the SCR1 is connected to the filter delay circuit and the chip control module as a control signal input terminal for filtering or delaying the trigger signal and stabilizing the triggering process.

[0025] Working principle: SCR1 is a controllable rectifier. When the gate receives a high-level signal, it turns on, connecting the main circuit to GND (equivalent to a short circuit), and quickly cuts off the power supply to the load; when there is no signal at the gate, it turns off, and the main circuit works normally.

[0026] In this embodiment, the SCR1 is model CR03, with its anode and cathode connected in series in the main circuit, and the G terminal (gate) used to receive the trigger signal.

[0027] The capacitance of the first capacitor C1 is 150nF, and the resistance of the fourth resistor R4 is 10KΩ. The first capacitor C1 and the fourth resistor R4 are connected in series, with one end connected to the gate (G) of the silicon controlled rectifier (SCR1) and the other end grounded (GND). This is used to filter and delay the trigger signal and stabilize the triggering process of the SCR1.

[0028] In this embodiment, the control trigger module further includes a voltage divider circuit consisting of a first resistor R1, a second resistor R2, and a third resistor R3 connected in series. One end of the voltage divider circuit is connected to the anode of the silicon controlled rectifier SCR1 and the first end of the rectifier bridge, and the other end is connected to the chip control module. It is used to divide the rectified DC voltage and provide an input voltage signal to the control trigger module.

[0029] Specifically, the resistance values ​​of the first resistor R1, the second resistor R2, and the third resistor R3 are all 56KΩ, and the three are connected in series to form a voltage divider circuit. The input terminal of the voltage divider circuit is connected to the output terminal of the rectifier module, and the output terminal is connected to the chip control module. It is used to divide the rectified DC voltage and provide an input voltage signal to the chip control module.

[0030] The control trigger module also includes a current-limiting resistor R6. One end of the current-limiting resistor R6 is connected to the OUT pin of the chip control module, and the other end is connected to the gate (G) of the silicon controlled rectifier (SCR1). It is used to limit the current flowing into the gate (G) and protect the SCR1. The resistance of the current-limiting resistor R6 is 10KΩ. The chip U1 outputs a control signal through its OUT pin, which is transmitted to the gate (G) of the SCR1 via the current-limiting resistor R6, controlling the SCR1's conduction and cutoff.

[0031] In this embodiment, the chip control module includes a chip U1. The VDD+ pin of the chip U1 is connected to the first end of the rectifier bridge through a fifth resistor R5 and a second capacitor C2. The fifth resistor R5 limits the inflow current, and the second capacitor C2 is used to filter out high-frequency ripple in the power supply, providing a stable 3.3V DC power supply for the chip U1.

[0032] Specifically, the VDD+ pin of the chip U1 is connected to the output of the rectifier module through a filter circuit composed of the fifth resistor R5 and the second capacitor C2; the resistance of the fifth resistor R5 is 3KΩ and the capacitance of the second capacitor C2 is 10uF, which are used to provide a stable DC power supply for the chip U1 and filter out power ripple.

[0033] The chip U1 is model APX823-26W5G-7, and its pins include NC (no pin), DS (signal detection pin), VSS (ground pin), VDD+ (power supply pin) and OUT (output pin).

[0034] Working principle: U1 integrates a signal processing unit and logic judgment circuit. It acquires the voltage signal after voltage division in real time through the DS pin and compares it with the internally preset overvoltage and overcurrent thresholds. When a signal is detected to exceed the threshold (such as overvoltage causing the voltage signal to be too high, or overcurrent causing the coil voltage drop to be too large, indirectly causing the signal to be abnormal), U1 outputs a high level through the OUT pin, which is transmitted to the G terminal of SCR1 through R6, triggering SCR1 to conduct and quickly cut off the circuit. After the fault is cleared, the signal returns to the normal range, the OUT pin of U1 outputs a low level, SCR1 is cut off, and the circuit automatically resumes operation. Working principle: SCR1 is a controllable rectifier device. When the gate receives a high-level signal, it conducts, connecting the main circuit to GND (equivalent to a short circuit), quickly cutting off the load power supply; when there is no signal at the gate, it is cut off, and the main circuit works normally.

[0035] The working process of this device is as follows: 1. Normal working status: AC power is connected via L and N, and MOV1 (07D561K) is on standby; current flows into the rectifier module via line diagram and S1 (closed), and is rectified into DC power by D1-D4; the voltage divider circuit (R1-R3) divides the DC voltage and transmits it to the DS pin of U1. U1 detects that the signal is normal, the OUT pin outputs a low level, SCR1 is cut off, and the load is powered normally.

[0036] 2. Overvoltage protection: When the voltage between L and N exceeds the operating threshold of MOV1, the resistance of MOV1 drops sharply, releasing the overvoltage energy. At the same time, the voltage divider circuit transmits an overvoltage signal to U1. U1 detects the abnormality through the DS pin, and the OUT pin outputs a high level, which triggers SCR1 to conduct through R6, cutting off the power supply to the load. After the voltage returns to normal, MOV1 resets, U1 controls SCR1 to turn off, and the circuit recovers.

[0037] 3. Overcurrent protection: When an overcurrent occurs in the circuit, the coil current increases, the magnetic field strengthens, triggering S1 to trip, and the main circuit is disconnected. At the same time, the overcurrent causes the rectified voltage signal to be abnormal. U1 detects the fault through the DS pin, the OUT pin outputs a high level, and SCR1 conducts to assist in power-off. After the overcurrent disappears, the coil magnetic field weakens, S1 closes automatically, U1 controls SCR1 to turn off, and the circuit is restored.

[0038] The above description is merely a preferred embodiment of this utility model, but the scope of protection of this utility model is not limited thereto. Any variations or substitutions that can be conceived by those skilled in the art within the scope of the technology disclosed in this utility model are included within the scope of protection of this utility model. Therefore, the scope of protection of this utility model should be determined by the scope of the claims.

Claims

1. A detection protection device with overvoltage and overcurrent protection functions, characterized in that, It includes a power input module, an overcurrent protection module, a rectification module, a control trigger module, and a chip control module; The power input module is connected to an AC power source through terminal L and terminal N; The rectifier module is connected to the power input module and is used to convert AC power into DC power. The overcurrent protection module is connected in series between the power input module and the rectifier module, and is used to detect overcurrent and trigger power-off protection. The chip control module is connected to the rectifier module and the control trigger module, and is used to process the detection signal and output control commands. The control trigger module is connected to the rectifier module and the chip control module, and is used to receive control signals and perform circuit switching operations.

2. The detection protection device with overvoltage and overcurrent protection function according to claim 1, characterized in that, In the power input module, a varistor (MOV1) is connected in parallel between the terminal L and the terminal N. The varistor (MOV1) is of model 07D561K and is used to implement overvoltage protection.

3. A detection and protection device with overvoltage and overcurrent protection functions according to claim 2, characterized in that, The overcurrent protection module includes a coil and a trip switch (S1) connected to each other; the coil is connected in series in the main circuit between the power input module and the rectifier module, and the trip switch (S1) works in conjunction with the coil to trigger the trip circuit to disconnect when there is an overcurrent.

4. A detection and protection device with overvoltage and overcurrent protection functions according to claim 1, characterized in that, The rectifier module consists of a rectifier bridge composed of a first diode (D1), a second diode (D2), a third diode (D3), and a fourth diode (D4). The cathodes of the first diode (D1) and the second diode (D2) are connected to form the first terminal of the bridge rectifier circuit; the anodes of the second diode (D2) and the fourth diode (D4) are connected to form the second terminal of the bridge rectifier circuit; the anodes of the fourth diode (D4) and the third diode (D3) are connected to form the third terminal of the bridge rectifier circuit; and the cathodes of the third diode (D3) and the first diode (D1) are connected to form the fourth terminal of the bridge rectifier circuit. The first terminal of the rectifier bridge is connected to the control trigger module and the chip control module; the second terminal of the rectifier bridge is connected to the terminal L; the third terminal of the rectifier bridge is connected to the control trigger module and grounded; and the fourth terminal of the rectifier bridge is connected to the trip switch (S1).

5. A detection and protection device with overvoltage and overcurrent protection functions according to claim 4, characterized in that, The control trigger module includes a silicon controlled rectifier (SCR1) and a filter delay circuit consisting of a first capacitor (C1) and a fourth resistor (R4). The anode of the silicon controlled rectifier (SCR1) is connected to the first end of the rectifier bridge, the cathode of the silicon controlled rectifier (SCR1) is grounded, and the gate (G) of the silicon controlled rectifier (SCR1) is connected to the filter delay circuit and the chip control module.

6. A detection and protection device with overvoltage and overcurrent protection functions according to claim 5, characterized in that, The control trigger module also includes a voltage divider circuit consisting of a first resistor (R1), a second resistor (R2), and a third resistor (R3) connected in series. One end of the voltage divider circuit is connected to the anode of the silicon controlled rectifier (SCR1) and the first end of the rectifier bridge, and the other end is connected to the chip control module.

7. A detection and protection device with overvoltage and overcurrent protection functions according to claim 5, characterized in that, The control trigger module also includes a current-limiting resistor (R6), one end of which is connected to the OUT pin of the chip control module, and the other end is connected to the gate of the silicon controlled rectifier (SCR1).

8. A detection and protection device with overvoltage and overcurrent protection functions according to claim 5, characterized in that, The chip control module includes a chip (U1), whose VDD+ pin is connected to the first end of the rectifier bridge via a fifth resistor (R5) and a second capacitor (C2).

9. A detection and protection device with overvoltage and overcurrent protection functions according to claim 8, characterized in that, The chip (U1) is model APX823-26W5G-7.

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