PCB board-mounted surge protection device

Abstract

PCB board-mounted surge protection device, including the surge protection components which form surge protection for the protected circuit on the PCB board, the surge protection components are welded on the PCB board, characterized in that: further comprising a tripping device for tripping protection of the surge protection components, the tripping device is welded on the PCB board and is in series with the surge protection components to form a tripping protection circuit, the tripping protection circuit is in parallel with the protected circuit, the tripping device trips off with the overheat, overcurrent or overload of the surge protection components, and the tripping protection circuit is disconnected. The present application realizes reliable and effective front-end protection for the surge protection components on the PCB board, ensures that the surge protection circuit is disconnected in time when the surge protection components are overheated, overcurrent or overloaded, prolongs the service life of the surge protection components, improves the surge protection reliability of the protected circuit on the PCB board, and meets the installation requirements of compactness on the circuit board.

Description

Technical Field

[0001] This invention relates to a PCB-mounted surge protection device, belonging to the field of electrical equipment protection technology. Background Technology

[0002] As electronic components become increasingly miniaturized and integrated, traditional power surge protectors are far from meeting the needs of current technology, especially in situations where circuit boards with high-density component placement have limited space, particularly in the height direction. When used on PCBs, surge protectors or surge protection components are typically limited by factors such as installation space and size, making it difficult to provide reliable overheat or overcurrent protection. Currently, overcurrent protection is usually achieved using common overcurrent fuses. However, using overcurrent fuses for surge protection components presents several problems, including small-current fuses failing to withstand lightning current, leading to malfunctions, and large-current fuses failing to melt during short circuits.

[0003] The relevant existing patent documents retrieved include:

[0004] 1. CN201220712885.4 - A PCB board lightning protection tripping device;

[0005] 2. CN201821913798.9 - A surge protection device that directly trips on a PCB;

[0006] 3. CN201920629494.8 - A PCB-onboard surge protector;

[0007] 4. CN201922280516.7 - A three-phase power supply surge protector;

[0008] 5. CN202021163700.X - A small PCB-based SPD that can meet T1 level lightning current requirements. Summary of the Invention

[0009] The PCB-mounted surge protection device provided by this invention connects a trip unit in series with the surge protection components on the PCB board, providing overheat, overcurrent, and overload protection for the surge protection components. It provides reliable and effective front-end protection for the surge protection components on the PCB board, ensuring that the surge protection circuit disconnects in time when the surge protection components are overheated, overcurrent, or overloaded, extending the service life of the surge protection components, improving the surge protection reliability of the protected circuit on the PCB board, reducing the space volume of the trip unit, and meeting the compact installation requirements of the circuit board.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] A PCB-mounted surge protection device includes surge protection components that provide surge protection for a protected circuit on a PCB board. The surge protection components are soldered onto the PCB board. The device is characterized by further including a trip unit that provides trip protection for the surge protection components. The trip unit is soldered onto the PCB board and connected in series with the surge protection components to form a trip protection circuit. The trip protection circuit is connected in parallel with the protected circuit. The trip unit trips when the surge protection components overheat, experience overcurrent, or become overloaded, thus disconnecting the trip protection circuit.

[0012] Preferably, it also includes an alarm contact board soldered to the detection circuit on the PCB board. The alarm contact board has signal contacts corresponding to the trip unit, and the signal contacts contact the trip unit when the trip unit trips.

[0013] Preferably, the trip unit is a double-layer structure that covers the surge protector element. The lower layer is connected to the surge protection element and the protected circuit respectively, and the upper layer provides tripping power for the trip unit.

[0014] Preferably, the trip unit includes a lower welding plate that covers the surge protection component and an upper power plate connected above the lower welding plate. One end of the lower welding plate is low-temperature welded to the series welding end of the surge protection component to form a trip protection circuit. The other end of the lower welding plate and the parallel welding end of the surge protection component are respectively connected to the two poles of the protected circuit to form a parallel connection between the trip protection circuit and the protected circuit. The upper power plate pulls the lower welding plate to swing upward as the lower welding plate trips with the surge protection component.

[0015] Preferably, one end of the lower welding piece has a high-temperature welding foot, and the other end has a low-temperature welding foot. The high-temperature welding foot is welded to one pole of the protected circuit at a high temperature, and the low-temperature welding foot is welded to the series welding terminal at a low temperature. The upper power piece is a metal spring with upward elasticity. One end is connected to the high-temperature welding foot, and the other end overlaps on the lower welding piece. As the lower welding piece trips with the surge protection element, it swings upward and contacts the signal contact.

[0016] Preferably, the section of the lower welding sheet near the low-temperature welding foot is an overcurrent protection section, which melts when the surge protection device experiences overcurrent or overload.

[0017] Preferably, both the high-temperature soldering foot and the low-temperature soldering foot are right-angled. The horizontal side of the low-temperature soldering foot is close to the series soldering end and is soldered to the series soldering end by low-temperature solder. The horizontal side of the high-temperature soldering foot is close to the PCB board and is soldered to one pole of the protected circuit by ordinary high-temperature solder.

[0018] Preferably, the lower welding sheet has an outwardly extending overlap strip, the overlap strip is close to the top of the overcurrent protection section, and one end of the upper power sheet has an overlap edge that overlaps with the overlap strip. The overlap strip extends into the upper power sheet and presses against the overlap edge to restrict the upper power sheet from swinging upward.

[0019] Preferably, one end of the upper power plate is a contact end corresponding to the signal contact, the overlapping edge is set on the contact end, the contact end is suspended and does not contact the PCB board, and contacts the signal contact as the upper power plate swings upward.

[0020] Preferably, the lower welding sheet and the upper power sheet are integrally formed, and the overcurrent protection section is the weakest section with the smallest load-bearing area processed on the lower welding sheet.

[0021] The beneficial effects of the invention are:

[0022] 1. The PCB-mounted surge protection device of the present invention connects a trip unit in series with the surge protection components on the PCB board to protect the surge protection components. When the current of the surge protection components deteriorates and increases, the heat generated by the components themselves is quickly conducted to the trip unit. The trip unit overheats and trips, promptly disconnecting the surge protection circuit, thus providing overheat protection for the surge protection components. When a short circuit or overcurrent occurs in the surge protection components, the trip unit itself melts and promptly disconnects the surge protection circuit, thus providing overcurrent and overload protection for the surge protection components. The trip unit has a strong surge current withstand capability and will not malfunction due to surge current discharge. The trip unit is designed with different tripping temperatures, tripping currents, and overload surge currents according to the protection requirements of surge protection components to achieve the best protection effect. It replaces the overcurrent fuse in surge protection components and provides reliable and effective front-end protection for surge protection components on the PCB board. It overcomes the technical defects of surge protection components when used on PCB boards, such as incomplete failure protection or overcurrent protection being too sensitive and prone to false tripping. It ensures that the surge protection circuit disconnects in time when the surge protection component is overheated, overcurrent, or overloaded, extends the service life of the surge protection component, and improves the surge protection reliability of the protected circuit on the PCB board.

[0023] 2. An alarm contact plate is soldered onto the PCB board. When the trip unit trips, it contacts the signal contacts on the alarm contact plate. The signal contacts transmit a trip alarm signal to the controller on the PCB board through the detection circuit on the PCB board, enabling the trip unit to have a real-time trip signal alarm function. This allows for real-time monitoring of the on / off status of the surge protection line, further improving the reliability of the surge protection.

[0024] 3. The trip unit is designed as a double-layer structure that covers the surge protection component. The upper layer is connected to the surge protection component and the protected surge, and the upper layer provides the tripping power. The trip unit and the tripping movement of the trip unit only occupy the space above the surge protection component, reducing the space volume of the trip unit and meeting the installation requirements of compact space on the circuit board. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a PCB-based surge protection device in a specific implementation.

[0026] Figure 2 This is a block diagram showing the structure of a surge protection circuit connected in parallel with the protected circuit.

[0027] Figure 3 This is a schematic diagram of a PCB-mounted surge protection device tripping due to overheating.

[0028] Figure 4 This is a schematic diagram of a PCB-mounted surge protection device tripping due to overcurrent or overload. Detailed Implementation

[0029] The following is combined with Figures 1-4 The embodiments of the present invention will be described in detail below.

[0030] A PCB-mounted surge protection device includes a surge protection component 1 that provides surge protection to a protected circuit on a PCB board. The surge protection component 1 is soldered onto the PCB board. The device is characterized by further including a trip unit 2 that provides trip protection for the surge protection component 1. The trip unit 2 is soldered onto the PCB board and connected in series with the surge protection component 1 to form a trip protection circuit. The trip protection circuit is connected in parallel with the protected circuit. The trip unit 2 trips when the surge protection component 1 overheats, experiences overcurrent, or is overloaded, thus disconnecting the trip protection circuit.

[0031] The PCB-mounted surge protection device described above connects a trip unit 2 in series with the surge protection component 1 on the PCB board to protect the surge protection component 1. When the current of the surge protection component 1 deteriorates and increases, the heat generated by the component itself is quickly conducted to the trip unit 2. The trip unit 2 overheats and trips, promptly disconnecting the surge protection circuit, thus providing overheat protection for the surge protection component. When a short circuit or overcurrent occurs in the surge protection component 1, the trip unit 2 melts and promptly disconnects the surge protection circuit, providing overcurrent and overload protection for the surge protection component. The trip unit 2 has a strong surge current withstand capability and will not malfunction due to surge current discharge. The trip unit 2 is designed with different tripping temperatures, tripping currents, and overload surge currents according to the protection requirements of surge protection components to achieve the best protection effect. It replaces the overcurrent fuse in surge protection components and provides reliable and effective front-end protection for surge protection components on PCB board 100. It overcomes the technical defects of surge protection components on PCB board that fail to provide complete protection or are too sensitive to overcurrent protection and are prone to false tripping. It ensures that the surge protection circuit of surge protection component 1 is disconnected in time when overheated, overcurrent, or overloaded, extends the service life of surge protection components, and improves the surge protection reliability of the protected circuit on PCB board.

[0032] This includes an alarm contact plate 3 soldered to the detection circuit on the PCB board 100. The alarm contact plate 3 has a signal contact 31 corresponding to the trip unit. The signal contact 31 contacts the trip unit 2 when the trip unit trips. By soldering the alarm contact 3 onto the PCB board 100, the trip unit 2's tripping movement contacts the signal contact 31 on the alarm contact plate 3. The signal contact 31 transmits a trip alarm signal to the controller on the PCB board through the detection circuit on the PCB board, enabling the trip unit to have a real-time trip signal alarm function. This allows for real-time monitoring of the on / off status of the surge protection line, further improving the reliability of the surge protection.

[0033] The trip unit 2 is a double-layer structure that covers the surge protector element 1. The lower layer is connected to both the surge protector element 1 and the protected circuit, while the upper layer provides the tripping force for the trip unit 2. The trip unit and its tripping motion only occupy the space above the surge protector element, reducing the size of the trip unit and meeting the compact installation requirements on the circuit board.

[0034] The trip unit 2 includes a lower welding piece 4 that covers the surge protection component 1 and an upper power piece 5 connected above the lower welding piece 4. One end of the lower welding piece 4 is low-temperature welded to the series welding end 11 of the surge protection component 1 to form a trip protection circuit. The other end of the lower welding piece 4 and the parallel welding end 12 of the surge protection component 1 are respectively connected to the two poles of the protected circuit to form a parallel connection between the trip protection circuit and the protected circuit. The upper power piece 5 pulls the lower welding piece 4 to swing upward as the lower welding piece 4 is tripped from the surge protection component 1. One end of the lower layer solder pad 4 is low-temperature soldered to the series soldering terminal 11, connecting the trip unit 2 and the surge protection component 1 in series to form a surge protection circuit. The lower layer solder pad 4 and the surge protection component 1 are respectively connected to the two poles of the protected circuit on the PCB board, connecting the surge protection circuit and the protected circuit in parallel. The upper layer power plate 5 applies an upward force to the lower layer solder pad 4. When the deterioration current of the surge protection component 1 increases, the heat generated by the component itself is quickly conducted to the trip unit 2. The low-temperature soldering of the lower layer solder pad 4 and the series soldering terminal 11... When the contact point is melted, the surge protection circuit is tripped in time, providing overheat protection for the surge protection component and preventing it from overheating further. At the same time, the upper power plate 5 will drive the lower welding plate 4 to swing upward away from the melted position. During the upward swing, the upper power plate 5 will contact the signal contact 31, and the signal contact 31 will transmit the trip alarm signal to the controller. The overheat protection of the surge protection component 1 is timely and reliable. When the lower welding plate 4 and the series welding end 11 are completely melted, the lower welding plate 4 will swing upward in time, and the tripping reliability is high.

[0035] The lower welding piece 4 has a high-temperature welding foot 41 at one end and a low-temperature welding foot 42 at the other end. The high-temperature welding foot 41 is heat-resistant welded to one pole of the protected circuit, and the low-temperature welding foot 41 is low-temperature welded to the series welding terminal 11. The upper power piece 5 is a metal spring with upward elasticity. One end is connected to the high-temperature welding foot 41, and the other end overlaps the lower welding piece 4. As the lower welding piece 4 trips with the surge protection element 1, it swings upward and contacts the signal contact 31. The low-temperature welding foot 42 is low-temperature welded to the series welding terminal 11. When overheated, the weld melts. The high temperature of the high-temperature welding foot 41 keeps the connection stationary. The upward elasticity of the upper power piece 5 causes one end of the low-temperature welding foot 42 to swing upward and separate from the series welding terminal 11. When the upper power piece 5 contacts the signal contact 31, it swings into place.

[0036] The section of the lower welding piece 4 near the low-temperature welding foot 42 is an overcurrent protection section 43, which melts when the surge protection device experiences overcurrent or overload. When the surge protection device 1 experiences a short circuit or overcurrent, the overcurrent protection section 43 melts and disconnects the surge protection circuit in time. At the same time, the upper power piece 5 pulls the lower welding piece 4 upward to swing away from the melted position, forming a trip and ensuring that the surge protection circuit is completely disconnected. During the upward swing, the upper power piece 5 contacts the signal contact 31, and the signal contact 31 transmits a trip alarm signal to the controller, thus providing reliable overcurrent and overload protection for the surge protection device.

[0037] The high-temperature soldering foot 41 and the low-temperature soldering foot 42 are both right-angled. The horizontal side of the low-temperature soldering foot 42 is close to the series soldering end 11 and is soldered to the series soldering end 11 with low-temperature solder. The horizontal side of the high-temperature soldering foot 41 is close to the PCB board 100 and is soldered to one pole of the protected circuit with ordinary high-temperature solder. Because the horizontal side of the low-temperature soldering foot 42 is close to the series soldering end 11, when the current of the surge protection component 1 deteriorates, the heat on the surge protection component 1 will be quickly conducted to the low-temperature soldering foot 42, causing the low-temperature solder between the low-temperature soldering foot 42 and the series soldering end 11 to melt. The upward force of the upper power plate 5 pulls the low-temperature soldering foot 42 upward and away from the series soldering end 11 before the low-temperature soldering foot 42 and the series soldering end 11 are completely melted, thus tripping. The proximity of the low-temperature welding pin 42 to the series welding end 11 ensures that the surge protection component 1 will conduct heat to the low-temperature welding position in a timely manner, thus ensuring the timeliness of tripping. The upward force of the upper power plate 5 on the lower welding plate 4 also ensures the effectiveness of tripping, thus forming reliable overheat protection for the surge protection component 1.

[0038] The lower welding sheet 4 has an outwardly extending overlap strip 44, which is close to the top of the overcurrent protection section 43. One end of the upper power sheet 5 has an overlap edge 51 that overlaps with the overlap strip 44. The overlap strip 44 extends into the upper power sheet 5 and presses against the overlap edge 51 to restrict the upper power sheet 5 from swinging upward. The upper power piece 5 has an upward elastic force. The overlapping strip 44 extends into the upper power piece 5 and presses on the overlapping edge 51. Since both ends of the lower welding piece 4 are welded and positioned, the overlapping strip 44 can press on the overlapping edge 51 to form a constraint and positioning of the upper power piece 5. When the low temperature welding end 42 and the series welding end 11 melt or the overcurrent protection section 43 melts, the upper power piece 5 can no longer be positioned and constrained. The upper power piece 5 will swing upward, causing the lower welding strip 4 to swing upward. The double-layer structure of the upper power piece 5 and the lower welding piece 4 is simple. The tripping force is effectively applied to the lower welding strip 4, and the tripping reliability is high.

[0039] The upper power plate 5 has a contact end 52 corresponding to the signal contact 31 at one end. The overlapping edge 51 is set on the contact end 52, which is suspended and does not contact the PCB board 100. It comes into contact with the signal contact 31 as the upper power plate 5 swings upward. The contact between the contact end 52 and the signal contact 31 sends a trip alarm signal to the controller. At the same time, it limits the upward swing of the upper power plate 5 to prevent excessive swing of the upper power plate 5 from interfering with other components on the PCB board, thus meeting the design requirements of the compact space on the PCB board.

[0040] The lower welding piece 4 and the upper power piece 5 are integrally formed, which has a simple forming structure, does not require welding assembly, has high structural reliability, good overall strength, and a more stable and reliable structure. The overcurrent protection section 43 is the weakest section with the smallest carrying area processed on the lower welding piece 4. The overcurrent protection section 43 is formed by drilling, cutting and other processing to form the part with the smallest carrying area. When the overcurrent per unit area is large, it will heat up and melt, thereby realizing overcurrent and overload protection for surge protection components.

[0041] The working principle of the PCB onboard surge protection device described above is as follows:

[0042] When the current deterioration of surge protection component 1 increases, the heat generated by the component itself is quickly conducted to the low-temperature soldering pin 42. When the temperature reaches the solder melting point of the low-temperature soldering pin 42, the solder between the low-temperature soldering pin 42 and the series soldering terminal 11 melts from solid to liquid. At this time, the upper power plate 5 will swing upward with the lower soldering plate 4, causing the low-temperature soldering pin 42 to separate from the series soldering terminal 11, and the surge protection circuit will be disconnected. This achieves the purpose of separating surge protection component 1 from the protected circuit and realizing the function of overheat protection. The upward swing of the upper power plate 5 causes the contact terminal 52 to contact the signal contact 31 and sends a trip alarm signal to the controller.

[0043] When surge protection component 1 is short-circuited, a large short-circuit current will pass through the lower welding piece 4. The overcurrent protection section 43, due to its smallest cross-sectional area, will heat up and melt due to the large overcurrent per unit area. At this time, the upper power piece 5 will swing upward with the lower welding piece 4, disconnecting the surge protection circuit and separating the surge protection component from the protected circuit, thus realizing the function of short-circuit and overcurrent protection. The upward swing of the upper power piece 5 causes the contact end 52 to contact the signal contact 31, sending a trip alarm signal to the controller.

[0044] When the surge current in the surge protection circuit exceeds the expected value by a large margin, the overcurrent protection section 43 will also heat up and melt due to the smallest load area and large overcurrent per unit area. The upper power piece 5 will also swing upward with the lower welding piece 4, disconnecting the surge protection circuit and separating the surge protection component from the protected circuit, thus realizing the function of surge current overload protection. The upper power piece 5 swings upward, causing the contact end 52 to contact the signal contact 31 and sending a trip alarm signal to the controller.

[0045] The technical solutions of the embodiments of the present invention have been fully described above with reference to the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

Claims

1. A PCB-on-board surge protection device, comprising surge protection components that provide surge protection to the protected circuit on the PCB, wherein the surge protection components are soldered onto the PCB, characterized in that: It also includes a trip unit that trips to protect surge protection components. The trip unit is soldered on the PCB board and connected in series with the surge protection components to form a trip protection circuit. The trip protection circuit is connected in parallel with the protected circuit. The trip unit trips when the surge protection components overheat, overcurrent, or overload, thus disconnecting the trip protection circuit. The trip unit is a double-layer structure that covers the surge protector element. The lower layer is connected to the surge protection element and the protected circuit respectively, and the upper layer provides tripping power for the trip unit. The trip unit includes a lower welding plate that covers the surge protection component and an upper power plate connected above the lower welding plate. One end of the lower welding plate is low-temperature welded to the series welding end of the surge protection component to form a trip protection circuit. The other end of the lower welding plate and the parallel welding end of the surge protection component are respectively connected to the two poles of the protected circuit to form a parallel connection between the trip protection circuit and the protected circuit. The upper power plate pulls the lower welding plate to swing upward as the lower welding plate is tripped from the surge protection component. The section near the low-temperature welding foot on the lower welding sheet is an overcurrent protection section, which melts when the surge protection device experiences overcurrent or overload. The lower welding sheet has an outwardly extending overlapping strip, which is close to the top of the overcurrent protection section. One end of the upper power sheet has an overlapping edge that overlaps with the overlapping strip. The overlapping strip extends into the upper power sheet and presses against the overlapping edge to restrict the upper power sheet from swinging upward. The lower welding sheet is integrally formed with the upper power sheet, and the overcurrent protection section is the weakest section with the smallest carrying area processed on the lower welding sheet.

2. The PCB-mounted surge protection device according to claim 1, characterized in that: It also includes an alarm contact board soldered to the detection circuit on the PCB board. The alarm contact board has signal contacts corresponding to the trip unit. The signal contacts contact the trip unit when the trip unit trips.

3. The PCB-onboard surge protection device according to claim 1, characterized in that: The lower welding piece has a high-temperature welding foot at one end and a low-temperature welding foot at the other end. The high-temperature welding foot is welded to one pole of the protected circuit at a high temperature, and the low-temperature welding foot is welded to the series welding terminal at a low temperature. The upper power piece is a metal spring with upward elasticity. One end is connected to the high-temperature welding foot, and the other end overlaps the lower welding piece. As the lower welding piece trips with the surge protection device, it swings upward and contacts the signal contact.

4. The PCB-onboard surge protection device according to claim 3, characterized in that: Both the high-temperature soldering foot and the low-temperature soldering foot are right-angled. The horizontal side of the low-temperature soldering foot is close to the series soldering end and is soldered to the series soldering end by low-temperature solder. The horizontal side of the high-temperature soldering foot is close to the PCB board and is soldered to one pole of the protected circuit by ordinary high-temperature solder.

5. The PCB-onboard surge protection device according to claim 4, characterized in that: One end of the upper power plate is a contact end corresponding to the signal contact. The overlapping edge is set on the contact end. The contact end is suspended and does not contact the PCB board. It contacts the signal contact as the upper power plate swings upward.

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