Circuit capable of realizing picosecond-level protection and indication on transient high voltage

Abstract

The invention discloses a circuit capable of realizing picosecond-level protection and indication on transient high voltage. The circuit comprises an input end protection circuit, an output end load circuit and a fault indication circuit, the input end protection circuit comprises an input induction power supply and a ground wire; a bidirectional TVS 1 is connected between an input induction power supply and a ground wire. One side of the input induction power supply is connected in series with a resistive fuse 2 and an output end load circuit and is connected with an output end. The output end load circuit comprises a resistor I; two ends of the resistor I are connected in parallel with an LED-G work indicating lamp; the front end of the resistor I is connected with a bidirectional TVS II and a bidirectional TVS III; the fault indication circuit comprises a first resistive fuse, an inductor, a gas discharge tube, a bidirectional TVS, a second resistor and an LED-R fault indication lamp. The first resistive fuse is connected with the first bidirectional TVS in series. Two ends of the resistance-type fuse I are connected in parallel with an inductor and a gas discharge tube; two ends of the gas discharge tube are connected in parallel with the bidirectional TVS; the two ends of the bidirectional TVS are connected with a second resistor and an LED-R fault indicating lamp in parallel. The protection circuit can ensure safe use of a low-voltage loop in a middle-high voltage cable, and the safety is improved.

Description

Technical Field

[0001] This invention relates to a circuit that can provide picosecond-level protection and indication for transient high voltage, belonging to the field of electrical cable technology. Background Technology

[0002] Low-voltage protection circuits in cables are currently rarely used in the cable industry, especially in the field of cables for special electrical equipment. Therefore, the technology of protection circuits is still in its early stages. In the current product structure of the cable industry, low-voltage lines are often interspersed with high-voltage power cables. Low-voltage lines include control lines, signal lines, and LED strips. These low-voltage lines are inevitably subject to transient voltage impacts such as high-voltage leakage from power lines and lightning strikes, which can lead to overload breakdown or burnout of the low-voltage lines, and also pose safety hazards.

[0003] Currently, most protection circuits on the market use gas discharge tubes for primary protection and TVS (Transient Voltage Suppressor) for secondary protection, similar to surge protectors. However, the performance of such protection circuits gradually declines over time and with repeated use, and the response time is on the order of nanoseconds or higher, resulting in unsatisfactory performance. When a cable is in operation or already connected to a circuit, and the low-voltage line is subjected to transient voltage impacts (including leakage current, lightning strikes, etc.) due to improper cable wiring or other factors, the device of this invention can protect the low-voltage line embedded in the cable and effectively disconnect the low-voltage line of the entire cable, thereby improving cable safety and reducing economic losses. It can also withstand long-term transient voltage impacts. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides a circuit that can achieve picosecond-level protection and indication of transient high voltage, thereby achieving the effect of disconnecting the low-voltage circuit of the entire cable, and can also withstand long-term transient voltage impacts, thereby improving the safety of cable use and reducing economic losses.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is: a circuit that can realize picosecond-level protection and indication of transient high voltage, including an input protection circuit, an output load circuit and a fault indication circuit; the input protection circuit includes an input sensing power supply and a ground wire; a bidirectional TVS is connected between the input sensing power supply and the ground wire; a resistive fuse is connected in series on one side of the input sensing power supply and the output load circuit is connected to the output terminal; The output load circuit includes a resistor 1; an LED-G working indicator light is connected in parallel across the two ends of the resistor 1; and a bidirectional TVS 2, a bidirectional TVS 3, and an inductor 2 are connected to the front end of the resistor 1. The fault indication circuit includes a resistive fuse, an inductor, a gas discharge tube, a bidirectional TVS, a resistor, and an LED-R fault indicator light; the resistive fuse and the bidirectional TVS are connected in series; the inductor and the gas discharge tube are connected in parallel across the two ends of the resistive fuse; the bidirectional TVS is connected in parallel across the two ends of the gas discharge tube; and the resistor and the LED-R fault indicator light are connected in parallel across the two ends of the bidirectional TVS.

[0006] Furthermore, the input terminal is used to connect the input induced power supply; the output terminal is used to connect the load; in the load circuit, resistor one is connected in series in the output terminal; the LED-G working indicator is connected in parallel across resistor one; bidirectional TVS two and bidirectional TVS three are connected between the front end of resistor one and the ground wire to introduce energy to the ground, forming the first level of protection and the second level of protection respectively.

[0007] Furthermore, the two resistive fuses are connected in series between the input and output terminals to provide overcurrent protection, forming a fourth level of protection.

[0008] Furthermore, the bidirectional TVS is connected between the input terminal and the ground wire to absorb transient voltages and form a third level of protection.

[0009] Furthermore, there can be multiple inductors, depending on the number of coil turns, which can be connected in series with a resistive fuse.

[0010] Furthermore, the method includes the following steps; Step 1: When the input voltage is normal, the output LED strip terminal works normally. At this time, the LED-G working indicator light will illuminate normally, indicating that the circuit is working normally, and the LED-R fault indicator light will not illuminate. Step 2: When the circuit is subjected to a transient voltage surge, bidirectional TVS 2 and bidirectional TVS 3 will conduct first, diverting the transient energy to the ground and protecting the load. Step 3: The bidirectional TVS also provides protection at the input end, diverting some of the transient energy to the ground; Step 4: When the above protection fails, the resistive fuse 2 will disconnect the circuit, cutting off the connection between the input and output terminals to prevent transient voltage from impacting the LED strip. Step 5: When a transient voltage occurs, the bidirectional TVS may fail first, followed by the resistance fuse blowing. The inductor prevents sudden current changes, and the gas discharge tube and bidirectional TVS further clamp the voltage to prevent the transient voltage from damaging the LED-R fault indicator. When there is no transient voltage, the LED-R fault indicator will not light up to avoid false alarms.

[0011] The beneficial effects of this invention are: the protection circuit of this invention can ensure the safe use of low-voltage circuits in medium and high-voltage cables, increase safety, reduce losses, reduce after-sales costs, fill a market gap, greatly increase the convenience of users, and reduce the cost of use. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the output load circuit structure of the present invention; Figure 3 This is a schematic diagram of the fault indication circuit structure of the present invention; Figure 4 This is a schematic diagram of the protection circuit principle of Embodiment 2 of the present invention.

[0013] In the diagram: 1. Resistor 1, 2. LED-G working indicator, 3. Bidirectional TVS 1, 4. Resistive fuse 1, 5. Inductor 1, 6. Gas discharge tube, 7. Bidirectional TVS, 8. Resistor 2, 9. LED-R fault indicator, 10. Resistive fuse 2, 11. Bidirectional TVS 2, 12. Bidirectional TVS 3, 13. Inductor 2. Detailed Implementation

[0014] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of the invention.

[0015] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of this invention is for the purpose of describing particular embodiments only and is not intended to limit the invention.

[0016] The present invention provides a circuit capable of providing picosecond-level protection and indication for transient high voltage, comprising an input protection circuit, an output load circuit, and a fault indication circuit; the input protection circuit includes an input sensing power supply and a ground wire; a bidirectional TVS-3 is connected between the input sensing power supply and the ground wire; a resistive fuse-10 is connected in series on one side of the input sensing power supply, and the output load circuit is connected to the output terminal. The output load circuit includes resistor 1; LED-G working indicator light 2 is connected in parallel across the two ends of resistor 1; bidirectional TVS 11, bidirectional TVS 3 12 and inductor 13 are connected to the front end of resistor 1. The fault indication circuit includes a resistive fuse 4, an inductor 5, a gas discharge tube 6, a bidirectional TVS 7, a resistor 8, and an LED-R fault indicator 9; the resistive fuse 4 is connected in series with the bidirectional TVS 3; the inductor 5 and the gas discharge tube 6 are connected in parallel across the resistive fuse 4; the bidirectional TVS 7 is connected in parallel across the gas discharge tube 6; the resistor 8 and the LED-R fault indicator 9 are connected in parallel across the bidirectional TVS 7.

[0017] The input terminal is used to connect the input induced power supply; the output terminal is used to connect the load; in the load circuit, resistor 1 is connected in series in the output terminal; LED-G working indicator 2 is connected in parallel across resistor 1; bidirectional TVS 11 and bidirectional TVS 3 12 are connected between the front end of resistor 1 and the ground wire to introduce energy to the ground, forming the first level of protection and the second level of protection respectively; the inductor (13) improves the response time of the subsequent circuit.

[0018] In this embodiment, the resistive fuse 210 is connected in series between the input and output terminals to provide overcurrent protection, forming the fourth level of protection.

[0019] In this embodiment, the bidirectional TVS-3 is connected between the input terminal and the ground line to absorb transient voltages and form a third level of protection.

[0020] In this embodiment, there can be multiple inductors 5, depending on the number of coil turns, which can be connected in series with the resistive fuse 10.

[0021] A method for implementing picosecond-level protection and indication of transient high voltage circuitry includes the following steps; Step 1: When the input voltage is normal, the output terminal works normally. At this time, LED-G indicator light 2 will light up normally, indicating that the circuit is working normally. LED-R fault indicator light 9 will not light up. Step 2: When the circuit is subjected to a transient voltage surge, bidirectional TVS 211 and bidirectional TVS 312 will conduct first, diverting the transient energy to the ground and protecting the load. Step 3: The bidirectional TVS-3 also provides protection at the input end, diverting some transient energy to the ground; Step 4: When the above protection fails, the resistive fuse 210 will disconnect the circuit, cutting off the connection between the input and output terminals to prevent transient voltage from impacting the LED strip. Step 5: When a transient voltage occurs, the bidirectional TVS-3 may fail first. Subsequently, the resistive fuse-4 blows, the inductor 5 prevents sudden current changes, and the gas discharge tube 6 and bidirectional TVS 7 further clamp the voltage to prevent the transient voltage from damaging the LED-R fault indicator 9. When there is no transient voltage, the LED-R fault indicator (⑨) will not light up to avoid false alarms.

[0022] The low-voltage circuit of the following embodiments of the present invention takes a light strip as an example. The schematic diagram of the light strip is as follows. Figure 1 The green work indicator light is visible. Figure 2 The red fault indicator light is visible. Figure 3 : In this invention, such as Figure 3 A resistor 1 is connected in series in the load circuit, and an LED-G indicator light is connected in parallel across the resistor. Because the load is a constant current source, the voltage increases with the load capacity, so connecting an indicator light in parallel would be insufficient and would affect the load's operation. When the circuit is subjected to a transient voltage surge, bidirectional TVS 2-11 protects the load by diverting energy to ground, and bidirectional TVS 3-12, the secondary protection, also diverts energy to ground. Resistive fuse 2-10 provides the third level of protection for the LED strip. When all the preceding protections fail, resistive fuse 2-10 will disconnect the circuit, thus protecting the LED strip. If the transient voltage persists, it will continuously impact the fault indicator light for an extended period. Therefore, when a transient voltage occurs, bidirectional TVS 3 will fail first and then conduct, while resistive fuse 4 will also fail and then open the circuit. At this point, the transient voltage will travel down through inductor 5. Under the protection of inductor 5, the gas discharge tube 6 and bidirectional TVS 7 can protect the LED-R fault indicator light 9 from damage for a long time. When there is no transient voltage, LED-R fault indicator 9 should not light up. This also reduces costs for users, achieving energy conservation, emission reduction, and ease of use.

[0023] Specific scenario 1: The power cable has a 70mm² conductor and a voltage rating of 3.6kV. The power core consists of the power conductor, inner shield, insulation, and outer shield. The outer shield includes both insulating shield and braided metal shield. Three power wires are twisted into a cable, with each pair of power wires tangent to the others. The three gaps in the cable core are used to place the LED strip, ground wire, and LED strip return line, respectively. Finally, a transparent outer sheath is extruded over the cable core to ensure that the light can pass through it.

[0024] The LED strip is composed of LED beads connected in series and parallel. The strip is 300 meters long and its circuit connects to the protection circuit. When the cable is powered, the LEDs illuminate. During use, the power line discharges into the LED strip circuit, causing a transient voltage that impacts the protection circuit and the LED strip. If the number of discharges is small, the circuit will directly activate protection, and the fault indicator light may not illuminate. If the transient voltage impact is continuous, the fault indicator light will illuminate, and then the operating indicator light will turn off, indicating that the LED strip is protected.

[0025] Specific Scenario 2: The power cable has a 95mm² conductor and a voltage rating of 6kV. The power core consists of the power conductor, inner shield, insulation, and outer shield. The outer shield includes both insulating shield and braided metal shield. Three power wires are twisted into a cable, with each pair of power wires tangent to the others. The three gaps in the cable core are used to place the LED strip, ground wire, and LED strip return line, respectively. Finally, a translucent outer sheath is extruded over the cable core to ensure that the light can pass through it.

[0026] The LED strip is composed of LED beads connected in series and parallel. The strip is 300 meters long and connects to the return line and protection circuit, forming a loop. When the cable is powered, the LEDs illuminate. During use, the power line discharges into the strip's circuit, causing transient voltage to impact the protection circuit and the strip. If the number of discharges is small, the circuit will directly activate protection, and the fault indicator light may not illuminate. If the transient voltage impact is continuous, the fault indicator light will illuminate, followed by the operation indicator light turning off, and the strip will be protected. When the protection circuit in the low-voltage circuit is removed, the strip will burn out after being subjected to no more than five transient voltage shocks.

[0027] Specific scenario 3: The power cable has a 120mm² conductor and a voltage rating of 8.7kV. The power core consists of the power conductor, inner shield, insulation, and outer shield. The outer shield includes both insulating shield and braided metal shield. Three power wires are twisted into a cable, with each pair of power wires tangent to the others. The three gaps in the cable core are used to place the LED strip, ground wire, and LED strip return line, respectively. Finally, a translucent outer sheath is extruded over the cable core to ensure that the light can pass through it.

[0028] The light strip can be made up of LED beads connected in series and parallel. The light strip is 300 meters long and is connected to the return line of the light strip and the protection circuit to form a loop. When the cable is connected to the power supply, the LEDs light up. When the power line of the cable discharges to the light strip circuit during use, the transient voltage will impact the protection circuit and the light strip. After withstanding 50,000 discharges, the protection circuit can still protect the low-voltage circuit.

[0029] In Embodiment 2 of this solution, refer to Figure 4 Alternatively, an inductor and a resistive fuse can be connected in series in a direct load circuit, with a gas discharge tube and a bidirectional TVS device connected to the downstream end of the inductor. These components form a continuous protection circuit. The gas discharge tube provides level 1 protection, the bidirectional TVS device provides level 2 protection, and the resistive fuse provides level 3 protection. This protection circuit does not require indicator lights and can continuously provide voltage surge withstand protection.

[0030] The device of this invention can protect the low-voltage lines embedded in the cable and can also disconnect the low-voltage lines of the entire cable, thereby improving the safety of cable use and reducing economic losses.

[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A circuit capable of providing picosecond-level protection and indication for transient high voltage, characterized in that, It includes an input protection circuit, an output load circuit, and a fault indication circuit; the input protection circuit includes an input sensing power supply and a ground wire; a bidirectional TVS-1 (3) is connected between the input sensing power supply and the ground wire, a resistor fuse-2 (10) is connected in series on one side of the input sensing power supply, and the output load circuit is connected to the output terminal. The output load circuit includes a resistor (1); an LED-G working indicator (2) is connected in parallel across the two ends of the resistor (1); and a gas discharge tube (11), a bidirectional TVS (12), and an inductor (13) are connected to the front end of the resistor (1). The fault indication circuit includes a resistive fuse (4), an inductor (5), a gas discharge tube (6), a bidirectional TVS (7), a resistor (8), and an LED-R fault indicator (9); the resistive fuse (4) is connected in series with the bidirectional TVS (3); the inductor (5) and the gas discharge tube (6) are connected in parallel across the two ends of the resistive fuse (4); the bidirectional TVS (7) is connected in parallel across the two ends of the gas discharge tube (6); the resistor (8) and the LED-R fault indicator (9) are connected in parallel across the two ends of the bidirectional TVS (7).

2. The circuit according to claim 1, capable of providing picosecond-level protection and indication for transient high voltage, is characterized in that... The input terminal is used to connect the input induced power supply; the output terminal is used to connect the load; in the load circuit, resistor one (1) is connected in series in the output terminal; the LED-G working indicator (2) is connected in parallel across resistor one (1); bidirectional TVS two (11) and bidirectional TVS three (12) are connected between the front end of resistor one (1) and the ground wire to introduce energy to the ground and build a zero potential difference across the load, which constitutes the first level of protection and the second level of protection respectively; the inductor (13) improves the response time of the subsequent circuit.

3. The circuit according to claim 1, capable of providing picosecond-level protection and indication for transient high voltage, is characterized in that... The resistive fuse 2 (10) is connected in series between the input and output terminals to provide overcurrent protection and constitute the fourth level of protection.

4. A circuit according to claim 1 that can realize picosecond-level protection and indication of transient high voltage, characterized in that, The bidirectional TVS-(3) is connected between the input terminal and the ground wire to absorb transient voltage and form the third level of protection.

5. A circuit according to claim 1 that can realize picosecond-level protection and indication of transient high voltage, characterized in that, The inductor (5) can be multiple, depending on the number of coil turns, and can be connected in series with a resistive fuse (10).

6. A method for a circuit capable of providing picosecond-level protection and indication of transient high voltage according to claim 1, characterized in that, Includes the following steps; Step 1: When the input voltage is normal, the output terminal works normally. At this time, the LED-G working indicator (2) lights up normally, indicating that the circuit is working normally. The LED-R fault indicator (9) does not light up. Step 2: When the circuit is subjected to a transient voltage surge, bidirectional TVS 2 (11) and bidirectional TVS 3 (12) will first conduct, diverting the transient energy to the ground and protecting the load; Step 3: The bidirectional TVS-1 (3) also provides protection at the input end, diverting a portion of the transient energy to the ground; Step 4: When the above protection fails, the resistor fuse 2 (10) will disconnect the circuit and cut off the connection between the input and output terminals to prevent transient voltage from impacting the LED strip. Step 5: When a transient voltage occurs, the bidirectional TVS-1 (3) is damaged first, then the resistive fuse-1 (4) blows, the inductor (5) prevents the current from changing suddenly, and the gas discharge tube (6) and the bidirectional TVS (7) further clamp the voltage to prevent the transient voltage from damaging the LED-R fault indicator (9). When there is no transient voltage, the LED-R fault indicator (9) will not light up to avoid false alarms.

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