Signal surge protection circuit with multi-stage protection

Abstract

The utility model relates to a signal surge protection circuit with multistage protection, comprising a protection branch, the protection branch comprises a first stage protection circuit, the input end of the first stage protection circuit receives an input electric signal; the first-stage protection circuit comprises a first discharge branch connected to a ground terminal; the input end of the second-stage protection circuit is connected with the output end of the first-stage protection circuit; the second-stage protection circuit comprises a second discharge branch connected to the grounding end; wherein when the input electric signal is between a first threshold value and a second threshold value, the first discharge branch is conducted and is communicated with the grounding end, and when the input electric signal exceeds the second threshold value, the second discharge branch is conducted and is communicated with the grounding end. The embodiment of the utility model adopts a multi-level protection design, and can cope with different levels of lightning strokes and power interferences.

Description

Technical Field

[0001] The utility model relates to a protection circuit for electronic equipment, in particular to a signal surge protection circuit with multi-level protection. Background Art

[0002] The main functions of signal surge protectors are twofold: one is to limit transient overvoltages caused by induced lightning in signal lines, and the other is to limit surges caused by the start and stop of electronic systems. Induced lightning is an overvoltage generated on the signal line through electromagnetic induction when lightning occurs nearby. The start and stop of electronic systems may cause transient voltages and currents on the power lines, which in turn affect the signal lines. Signal surge protectors can effectively suppress these electrical transient events and protect the normal operation and data security of electronic equipment. In some technologies, signal surge protectors mainly discharge current through the protection structure by setting up corresponding protection structures in the circuit when overvoltage signals are generated. The possible problem is that they cannot flexibly deal with various levels of lightning strikes and power interference. Utility Model Content

[0003] In view of the deficiencies of the prior art, the utility model discloses a signal surge protection circuit with multi-level protection.

[0004] The technical solution adopted by the utility model is as follows:

[0005] A signal surge protection circuit with multi-level protection includes a protection branch, wherein the protection branch includes: a first-level protection circuit, the input end of the first-level protection circuit receives an input electrical signal; the first-level protection circuit includes: a first leakage branch connected to a ground terminal; a second-level protection circuit, the input end of the second-level protection circuit is connected to the output end of the first-level protection circuit; the second-level protection circuit includes: a second leakage branch connected to the ground terminal; wherein, when the input electrical signal is between a first threshold value and a second threshold value, the first leakage branch is turned on and connected to the ground terminal, and the second leakage branch is turned off; when the input electrical signal exceeds the second threshold value, both the first leakage branch and the second leakage branch are turned on and connected to the ground terminal; and the second threshold value is greater than the first threshold value.

[0006] A further technical solution is as follows: the first leakage branch is specifically a transient suppression diode circuit.

[0007] Its further technical solution is: the first-level protection circuit also includes a diode rectifier circuit; the input end of the diode rectifier circuit is connected to the input terminal; the output end of the diode rectifier circuit is connected to the second-level protection circuit; the common end of the output end of the diode rectifier circuit and the input end of the second-level protection circuit is connected to the first leakage branch.

[0008] Its further technical solution is: the diode rectifier circuit includes a first diode and a second diode, the anode of the first diode is connected to the ground terminal through a first transient suppression diode, and the cathode of the first diode is connected to the anode of the second diode; the cathode of the second diode is connected to the ground terminal through a second transient suppression diode; the common end of the first diode and the second diode serves as the output end of the first-level protection circuit.

[0009] A further technical solution is: the second leakage branch is a discharge tube circuit.

[0010] A further technical solution is: the second-level protection circuit also includes a current limiting resistor; the current limiting resistor is connected between the output end of the first-level protection circuit and the input end of the second-level protection circuit.

[0011] A further technical solution is: the signal surge protection circuit includes a plurality of protection branches.

[0012] A further technical solution is that a plurality of protection branches are connected to the ground terminal through the same group of first leakage branches.

[0013] A further technical solution is that, among a plurality of protection branches, adjacent protection branches are connected to the ground terminal through the same group of second leakage branches.

[0014] The beneficial effects of the utility model are as follows:

[0015] 1. The embodiment of the utility model adopts a multi-level protection design, which can cope with different levels of lightning strikes and power interference. Since a discharge tube circuit is also provided, the flow capacity is large, which means that the lightning arrester can withstand a larger current impact, thereby protecting the equipment from damage.

[0016] 2. The utility model can respond quickly and provide efficient protection. The first leakage branch uses a transient suppression diode, which has an extremely fast response speed and a response rate of nanoseconds. This design can isolate excessive voltage and current in a very short time, thereby effectively protecting the equipment from the harm of lightning strikes. At the same time, it reduces the attenuation of signal strength and ensures the quality and stability of signal transmission.

[0017] 3. The utility model has high transmission frequency and low insertion loss. The utility model has a simple circuit structure and can maintain a high speed and stability when transmitting signals, reducing the attenuation and distortion during signal transmission. At the same time, the extremely low online resistance further reduces the unnecessary attenuation of signal strength, maximizing the distance of signal transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural block diagram of an embodiment of the utility model.

[0019] Figure 2 1 is a circuit diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0020] The specific implementation of the present utility model is described below in conjunction with the accompanying drawings.

[0021] Figure 1 1 is a structural diagram of an embodiment of the utility model. Figure 1 As shown, the signal surge protection circuit with multi-level protection includes an input terminal, a first-level protection circuit, a second-level protection circuit and an output terminal.

[0022] The input end of the first-level protection circuit receives an input electrical signal, which is specifically a voltage signal and / or a current signal. The first-level protection circuit includes a first leakage branch, which is connected to the ground terminal. In this embodiment, the first-level protection circuit also includes a rectifier circuit. The input end of the rectifier circuit is connected to the input terminal, and the output end of the rectifier circuit is connected to the second-level protection circuit. The first end of the first leakage branch is connected to the common end of the rectifier circuit and the second-level protection circuit, and the second end of the first leakage branch is grounded. In this embodiment, the first leakage branch is a transient suppression diode circuit.

[0023] Transient suppression diodes, also known as clamping diodes, can absorb surge power of up to several kilowatts. Its main feature is that under reverse application conditions, when subjected to a high-energy large pulse, its working impedance immediately drops to an extremely low conduction value, allowing large currents to pass through while clamping the voltage at a predetermined level. Its response time is only 10-12 milliseconds. As the first leakage branch of the first-level protection circuit, it can isolate excessive voltage and current in a very short time, thereby effectively protecting the equipment from the harm of lightning strikes.

[0024] The input end of the second-level protection circuit is connected to the output end of the first-level protection circuit, and the output end of the second-level protection circuit is connected to the output terminal. The second-level protection circuit includes a second leakage branch connected to the ground terminal. The second-level protection circuit also includes a current limiting resistor; the current limiting resistor is connected between the output end of the first-level protection circuit and the input end of the second-level protection circuit. In this embodiment, the second leakage branch is a discharge tube circuit.

[0025] Among them, when the input electrical signal is between the first threshold and the second threshold, the first leakage branch is turned on and connected to the ground terminal, and when the input electrical signal exceeds the second threshold, the second leakage branch is turned on and connected to the ground terminal. The first threshold and the second threshold are threshold electrical signals determined by the circuit elements and structures of the first leakage branch and the second leakage branch, respectively, and the first threshold is less than the second threshold. When the input electrical signal is less than the first threshold, the first leakage branch and the second leakage branch are not turned on to discharge, and the input electrical signal is not overvoltage at this time. When the input electrical signal is greater than the first threshold and less than the second threshold, the first leakage branch will be turned on, and the second leakage branch will not be turned on. When the input electrical signal is greater than the second threshold, the second leakage branch will be turned on. Those skilled in the art can select appropriate circuit elements as needed to realize the corresponding threshold conduction function. Different circuit elements have different thresholds for conducting electrical signals, which is common knowledge in the art.

[0026] When transient overvoltage enters the input terminal, the second leakage branch has a higher discharge voltage and a longer response time, and does not discharge and conduct quickly. Before the second leakage branch conducts and discharges, the first leakage branch will break down for the first time and discharge the transient current. As the current increases, the voltage drop is added to both ends of the second leakage branch, which promotes the second leakage branch to discharge as soon as possible and discharge a large current. When the discharge is turned on, it will present a low resistance state to achieve protection.

[0027] This embodiment adopts a multi-level protection design, which can cope with different levels of lightning strikes and power interference. Large flow capacity means that the lightning arrester can withstand larger current impacts, thereby protecting the equipment from damage.

[0028] Figure 2 1 is a circuit diagram of an embodiment of the utility model. Figure 2 A specific circuit structure implementation method is shown. Figure 2 As shown, in this embodiment, the protection circuit includes an input terminal P1, a first-level protection circuit, a second-level protection circuit and an output terminal P2. The protection circuit of this embodiment includes five protection branches.

[0029] The first-level protection circuit includes a diode rectifier circuit composed of diodes D1 to D10. The first leakage branch includes transient suppression diodes TVS1, transient suppression diodes TVS2 and transient suppression diodes TVS3. Taking the first protection branch as an example, in this protection branch, the diode rectifier circuit includes a first diode D2 and a second diode D5, the anode of the first diode D2 is connected to the ground terminal through the first transient suppression diode TVS3, and the cathode of the first diode D2 is connected to the anode of the second diode D6; the cathode of the second diode D6 is connected to the ground terminal through the second transient suppression diode TVS1; the common end of the first diode D2 and the second diode D6 serves as the output end of the first-level protection circuit. Similarly, if Figure 2As shown, the connection method from the second protection branch to the fifth protection branch is similar to that of the first protection branch. Those skilled in the art will know that in actual use, the number of protection branches in the protection circuit can be adjusted according to the actual electrical signal requirements of the circuit. In this embodiment, multiple protection branches are connected to the ground terminal through the same group of first leakage branches, which maximizes the function of circuit elements while playing a protective role.

[0030] The second-level protection circuit includes current limiting resistors R1 to R5, and the second leakage branch is a discharge tube circuit, including a first gas discharge tube GAS1, a second gas discharge tube GAS2 and a third gas discharge tube GAS3. The current limiting resistor is connected between the output end of the first-level protection circuit and the input end of the second-level protection circuit. Taking the first protection branch as an example, the first end of the current limiting resistor R1 is connected to the common end of the first diode D2 and the second diode D6, and the second end of the current limiting resistor R1 is connected to an input end of the first gas discharge tube GAS1, and is grounded through the first gas discharge tube GAS1. Similarly, the connection method from the second protection branch to the fifth protection branch is similar to that of the first protection branch. Among the multiple protection branches, adjacent protection branches are connected to the ground terminal through the same group of second leakage branches. In this embodiment, the second protection branch is also grounded through the first gas discharge tube GAS1, the third protection branch and the fourth protection branch are both grounded through the second gas discharge tube GAS2, and the fifth protection branch is grounded through the third gas discharge tube GAS3. While playing a protective role, the function of the circuit element is maximized.

[0031] This utility model is passed Figure 2 The specific circuit shown provides a protection circuit for secondary protection of signal surges. The first discharge branch is a transient suppression diode, and the second discharge branch is a discharge tube. When the transient overvoltage enters the input terminal P1, the discharge tube has a higher discharge voltage and a longer time response than the transient suppression diode. If it does not discharge and conduct quickly, the transient suppression diode will break down for the first time and discharge the transient current before the discharge tube is turned on and discharged. As the current increases, the voltage drop is added to both ends of the discharge tube, which promotes the discharge tube to discharge as soon as possible and discharge a large current. When the discharge is turned on, it will be in a low resistance state to achieve the protection function. The output terminal P2 is connected to the electronic equipment that needs to be protected.

[0032] The signal surge protection circuit disclosed in the utility model can effectively absorb or shunt overvoltage and overcurrent generated by electrical transient events, thereby protecting the connected electronic equipment from damage. This greatly prolongs the service life of the electronic equipment, reduces the equipment replacement and maintenance costs caused by electrical transient events, and can also improve system stability, ensuring that the system can still operate normally when a transient event occurs.

[0033] The above description is an explanation of the utility model, not a limitation of the utility model. The scope of the utility model is defined by the claims. The utility model can be modified in any form without violating the basic structure of the utility model.

Claims

1. A signal surge protection circuit with multi-level protection, characterized in that: The invention comprises a protection branch, wherein the protection branch comprises: A first-level protection circuit, wherein an input end of the first-level protection circuit receives an input electrical signal; the first-level protection circuit comprises: A first leakage branch connected to a ground terminal; A second-level protection circuit, wherein the input end of the second-level protection circuit is connected to the output end of the first-level protection circuit; the second-level protection circuit comprises: A second leakage branch is connected to the ground terminal; Among them, when the input electrical signal is between a first threshold and a second threshold, the first leakage branch is turned on and connected to the ground terminal, and the second leakage branch is cut off; when the input electrical signal exceeds the second threshold, both the first leakage branch and the second leakage branch are turned on and connected to the ground terminal; the second threshold is greater than the first threshold.

2. The signal surge protection circuit with multi-level protection according to claim 1, characterized in that: The first leakage branch is specifically a transient voltage suppressor diode circuit.

3. The signal surge protection circuit with multi-level protection according to claim 2, characterized in that: The first-level protection circuit also includes a diode rectifier circuit; the input end of the diode rectifier circuit is connected to the input terminal; the output end of the diode rectifier circuit is connected to the second-level protection circuit; the common end of the output end of the diode rectifier circuit and the input end of the second-level protection circuit is connected to the first leakage branch.

4. The signal surge protection circuit with multi-level protection according to claim 3, characterized in that: The diode rectifier circuit includes a first diode and a second diode, wherein the anode of the first diode is connected to the ground terminal through a first transient suppression diode, and the cathode of the first diode is connected to the anode of the second diode; the cathode of the second diode is connected to the ground terminal through a second transient suppression diode; and the common end of the first diode and the second diode serves as the output end of the first-level protection circuit.

5. The signal surge protection circuit with multi-level protection according to claim 1, characterized in that: The second leakage branch is a discharge tube circuit.

6. The signal surge protection circuit with multi-level protection according to claim 4, characterized in that: The second-level protection circuit also includes a current limiting resistor; the current limiting resistor is connected between the output end of the first-level protection circuit and the input end of the second-level protection circuit.

7. The signal surge protection circuit with multi-level protection according to any one of claims 1 to 6, characterized in that: The signal surge protection circuit includes a plurality of protection branches.

8. The signal surge protection circuit with multi-level protection according to claim 7, characterized in that: A plurality of protection branches are connected to the ground terminal through the same group of first leakage branches.

9. The signal surge protection circuit with multi-level protection according to claim 7, characterized in that: Among the multiple protection branches, adjacent protection branches are connected to the ground terminal through the same group of second leakage branches.

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