TW201628040A - Switch module with built-in surge absorption and open-circuit structure - Google Patents

Abstract

A switch module with a built-in surge absorption and open-circuit structure has an overcurrent protection switch as the body having a temperature-durable housing provided therein with a surge absorption and open-circuit structure, comprising: a compression spring, a fastener belt, a voltage-dependent resistor (i.e. surge absorber), a temperature-sensitive binder, and a rod. When a first contact and a second contact of the switch module are contacted and turned on, excessive surge or high voltage lightning stroke increases the voltage-dependent resistor temperature higher than the melting point of the temperature-sensitive binder, such that the temperature-sensitive binder is melted to loosen the fastener, making the compression spring upwardly bounce to push the rod to shift upward, further forcing the first contact on the flat spring to be released from the second contact. Thus, the first lug, when the bimetallic alloy sheet is not deformed and jumped off, can instantaneously form the open-circuit (OFF) with the second lug, so as to enhance the safety of electricity usage.

Description

Switch module for built-in surge absorption and breaking structure

The invention relates to a switch module for a built-in surge absorption and open circuit structure, in particular to a surge protection and open circuit protection structure built in an overcurrent protection switch.

1A and FIG. 1B disclose an overcurrent protection switch 10, which generally includes a housing 11 having a pressing block 12 at its upper end and a first tab 12a and a second portion at the bottom end. The first lug 12a is provided with a double metal contact spring 13 and a first contact 131. The second lug 12b is disposed above the first contact. a second contact 121 that can be in contact therewith; a linking member 14 having one end pivotally disposed at the bottom of the pressing block 12 and the other end interlocking with the free end of the double-bonded metal contact spring 13 by the pressing block 12 Pressing, driving the first contact 131 on the double metal contact spring 13 to contact the second contact 121 to form an ON state, and when the current is overloaded, the variability of the double metal contact spring 13 is The temperature is increased to deform, and the first contact 131 is disconnected from the second contact 121 to form an open circuit (OFF), thereby forming an overcurrent protection switch 10. This type of patent is found in patents 540811, 367091, 320335, 262168, 208384, etc. in China.

However, the above-mentioned conventional overcurrent protection switch 10 is designed for current overload. However, for sudden surges such as overshoot or high voltage lightning strikes, the voltage is instantaneously overloaded and there is no automatic open circuit (OFF) protection. The device is therefore easy to cause damage to the electrical appliance or has a safety hazard.

Therefore, in order to be safe in use, in many circuits, the conventional overcurrent protection switch 10 is additionally connected to a surge absorber (Metal Oxide Varistor) and a main power supply in series. Fuse, 俾 to prevent damage caused by overvoltage.

Figure 2 is a TW. No. 4,087, 172 (U.S. Patent No. 8,643, 462) patent, which discloses a "switch module" for preventing surge, which is applied to a power supply system. The switch module includes a power switch 105 and an insulating member. 106. A surge absorber 107 and a heat shrink tape 108. The insulating member 106 is inserted on the power switch 105; the surge absorber 107 is adjacent to the power switch 105; the heat shrink band 108 is connected to the surge absorber 107 and the insulating member 106, and the heat shrink band 108 is used for absorption by the surge. The temperature rise of the device 107 causes a contraction; when the insulating member 106 is in the initial state, the switching of the power switch is not affected, and when the heat shrinkage of the heat shrinkable tape 108 is sufficient to drive the insulating member to block the start of the power switch 105, the power switch 105 is in an open state. However, the components such as the insulating member 106, the surge absorber 107, and the heat shrinkable tape 108 are disposed outside the power switch 105, and are not integral with the power switch 105.

Therefore, in addition to the quality of the switch structure, the danger of high temperature, slow reaction, all have the limitations of excessive volume and too complex components, so more space and assembly processes are required, so only external switches can be used independently. The external method is applied and cannot be built into the switch, so there is still room for improvement.

According to UL1449 3rd Edition (2009.10), there is a specification for a new TYPE 4 SPD-component surge protector. At the same time, the new version is included in the Low Voltage surge arrester (Low Voltage surge Arrestres). The name changed from (Transient Voltage Surge Suppressors) to (Surge Protective Devices). It is obvious that the integration of components and the necessity of lightning protection (surge Arrestres)

Therefore, it is considered how to construct a surge absorption and breaking structure together in the overcurrent protection switch 10 with a fireproof and temperature resistant material casing, so as to ensure that the breaking operation of the lightning high voltage and the surge excess can be successfully completed. It is the subject of the present invention.

The main object of the present invention is to provide a switch module with built-in surge absorption and open circuit structure, which has the functions of a current overload protection switch and has the functions of surge absorption and disconnection in the same switch. It is enhanced by the efficacy of electricity safety.

Another object of the present invention is to build the built-in surge absorption and breaking structure into the switch module, so that it has overall safety and is convenient to be assembled in electrical products such as sockets.

In order to achieve the above effects, the technical features adopted by the present invention include: a casing having a pressing block at its upper end and a first lug as a positive input and a second as a positive output at the bottom end. a lug piece and a third lug as a negative input, wherein the first lug is connected with a double metal piece, and the double metal piece is provided with a contact spring and a first contact, and the upper part of the second lug The surface is provided with a second contact point with respect to the first contact; a linking member having one end pivoted at the bottom of the pressing block and the other end interlocking with the free end of the contact spring, by which the pressure is The pressing of the block drives the double-bonded metal piece and the contact spring on the deformation thereof, so that the first contact on the contact spring contacts the second contact to form an ON state, and when the current is overloaded, the The varicoseness of the double metal piece is deformed due to an increase in temperature, and the first contact on the contact spring is separated from the second contact to form an open circuit (OFF), thereby forming a current overload protection switch module. It is characterized by: The surge absorption and breaking structure is built in the housing and located under the contact spring 42 and includes: at least one varistor having an upper and lower surface and a set of electricity a connecting member; a compression spring disposed on a surface of the varistor; a strap having a first end and a corresponding second end, the strap compressing the compression spring at the varistor And the first end and the second end are in a correspondingly corresponding and close shape; at least one temperature-sensitive conjugate is glued to the surface of the varistor, and the first end of the strap is And bonding the second end to tightly bundle the compression spring; a rod member located on the bottom surface of the contact spring. Thereby, when the first contact is in contact with the second contact, a high voltage is encountered, the temperature of the varistor is instantaneously increased higher than the temperature of the temperature sensitive conjugate, and the temperature conjugate is forced. Melting and releasing the strap, so that the compression spring is lifted upward, thereby causing the lever to be displaced upward, forcing the first contact on the contact spring to disengage from the second contact, so that the first lug In the case that the double-bonded metal piece is not deformed and tripped, the second lug can be instantaneously opened (OFF) with a slight thrust.

According to the foregoing feature, the temperature-sensitive bonding material comprises any one selected from the group consisting of a non-metal heat-sensitive substance and a metal-based low-temperature fast-melting metal compound.

By means of the above-mentioned technical features, the invention solves the lack of the external surge absorber of the conventional current overload protection switch, utilizes the internal space of the general current overload protection switch for temperature and fire prevention, and cleverly builds a surge absorption and breaking structure, encounters the surge In the case of excessive or high-voltage lightning strikes, the varistor that generates heat and the temperature-sensitive joint that can be instantaneously melted are used to loosen the band, and the compression spring is used to push the rod member upward to release the first and second contacts. Quickly form an open circuit. Therefore, in addition to the current overload protection function, the present invention further has an overvoltage protection and a surge absorption function in the same switch, and has a surge over-circuit design, which is safe for use and convenient to use. Improved efficacy.

First, referring to FIG. 3 to FIG. 6 , a preferred embodiment of the present invention includes a housing 31 having a pressing block 32 at an upper end and a first lug 40 as a positive input at a bottom end. a second lug 50 as a positive output, and a third lug 60 as a negative input, wherein the first lug 40 is connected to a double metal piece 41, and a contact spring is disposed in the middle of the double metal piece 41. a piece 42 and a first contact 421, the upper portion 51 of the second lug 50 is provided with a second contact 511 which is in contact with the first contact 421; a linking member 33, the upper end thereof The pivoting portion is disposed at the bottom of the pressing block 32, and the bottom end of the double end metal piece 41 is connected to the free end 411. As shown in FIG. 4 and FIG. 4A, the double piece metal piece 41 is driven upward by the pressing of the pressing piece 32. Forcing the contact reed 42 to bounce downward, causing the first contact 421 thereon to contact the second contact 511 to form an ON state, and when the current is overloaded, the variability of the contact reed 41 rises due to temperature. Deformed high, jumping back to the state shown in Figure 3, and disengaging the first contact 421 from the second contact 511 Disconnection (OFF), according to a configuration of a current overload protection switch body of the switch module 30; However, the above prior art metal-based configuration (Prior Art), capacity is not repeated here.

The present invention is characterized in that, in a possible embodiment of the switch module 30 of the current overload protection switch, the upper portion 51 of the second lug 50 is provided with a notch 52 on the side of the second contact 511. A surge absorption and breaking structure 70 is built into the housing 31 and located below the contact spring 42 and includes:

At least one varistor (also referred to as a surge absorber) 71, the varistor 71 has an upper and lower surface 711 and a set of electrical connectors 712, which may be conductive wires, conductive sheets or A conductive member extending from the surface of the varistor 71 is acceptable.

a compression spring 73 is disposed on the surface 711 of the varistor 71; a strap 74 having a first end 741 and a corresponding second end 742, the strap 74 compressing the compression spring 73 The varistor 71 has the first end 741 and the second end 742 in a correspondingly facing configuration; that is, the compression spring 73 which is normally in an extended state is contracted by the strap 74 to be contracted by the pressing force. Become a shorter length.

The at least one temperature-sensitive adhesive 72 is adhesively adhered to one surface of the varistor 71, and the first end 741 and the second end 742 of the strap 74 are adhesively fixed on the surface of the varistor 71. Then, the band 74 is brought into an annular body to tighten the compression spring 73 so that its contraction is subjected to a pressing force to exhibit a short length. In this embodiment, the temperature-sensitive bonding material 72 may be composed of a non-metallic heat-sensitive substance or a metal-based low-temperature fast-melting metal compound (for example, a metal compound for a general fuse), but is not limited thereto. . Therefore, as long as the temperature rise of the varistor (surge absorber) 71 reaches the set temperature, and such a substance is melted, a conductive or non-conductive substance may be used when the temperature is not raised to a high temperature. This compound consists in a fixed melting point and fast chain-breaking melting characteristics. In addition, the material of the temperature sensing joint 72 and the belt 74 can be used for metal and non-metal interaction, for example, a non-metallic band and a metal-like temperature bonding joint, or a belt 74 and a temperature-sensitive joint. 72 is the same temperature sensing material and is adhered to the heating surface 711 of the varistor 71 is feasible. Therefore, as long as it can be adhered to the surface 711 of the varistor 71, and when the varistor 71 is heated, it can be melted to separate the band 74, which is generally known to the designer and will not be described.

a rod member 75 having an upper end penetrating the notch 52 of the upper portion 51 of the second lug piece 50, and when the first contact point 421 of the contact spring piece 42 contacts the second contact point 511, the position is The bottom surface of the contact spring 42 is provided. In this embodiment, the rod 75 can be provided with a base 751, and the base 751 abuts against the top surface of the compression spring 73, but is not limited thereto, for example, as long as the rod 75 The width of the compression spring 73 is greater than the top surface of the compression spring 73. The main function of the lever 75 is to push the contact spring 42 upward when the switch module 30 is abnormal, forcing the first contact 421 thereon to be disengaged from the second contact 511.

Referring to FIG. 5 and FIG. 5A , the first contact 421 and the second contact 511 are in contact with each other (ON), but a high voltage is encountered, so that the temperature of the varistor 71 rises instantaneously higher than the sense. When the melting value of the temperature bonding material 72 is forced, the temperature sensing joint 72 is forced to melt, and the belt 74 is loosened, so that the pressing force of the compression spring 73 disappears instantaneously and rises upward, thereby pushing the rod member 75 upward. Displacement, forcing the first contact 421 on the contact spring 42 to disengage from the second contact 511, so that the first lug 40 can be instantaneously deformed without being deformed and disengaged. An open circuit (OFF) is formed with the second lug 50.

6 is an exploded perspective view of the main components of the present invention, and the surge absorbing and breaking structure 70 of the present invention mainly includes the foregoing: a varistor (also referred to as a surge absorber) 71, a temperature sensitive joint 72, and a compression spring 73. , the strap 74 and the rod 75 are formed; please also show the surge absorption and breaking structure 70 between the first lug 40 and the second lug 50 as shown in each of FIGS. 3 to 5 . In this embodiment, the inner space of the casing 31 is provided with a stop surface 34 and a lateral positioning surface 35. The positioning surface 35 is disposed for positioning the upper portion 51 of the second lug 50. The position of the positioning surface 35 relative to the notch 52 of the upper portion 51 is provided with a through slot 36 for facilitating the passage of the rod 75; further, the inner space of the housing 31 is at the first tab 40 and Between the second lugs 50, a pair of oppositely facing slits 37 are provided for the two sides of the varistor 71 to be embedded, so that the entire surge absorbing and breaking structure 70 is firmly built in the housing 31. .

In the present invention, when the temperature of the varistor 71 is instantaneously raised to a preset value when the switch module 30 is overvoltage, the temperature-sensitive conjugate 72 pasted on the surface 711 of the varistor 71 is instantaneously melted. The varistor (Metal Oxide Varistor or Voltage Dependent Resistor, VDR), also known as varistor or surge absorber, is an electronic component with significant non-ohmic conductor properties. The resistance value changes with the external voltage, so its current - The voltage characteristic curve has significant nonlinearity and is widely used in electronic circuits to protect against damage to the circuit due to transient voltage surges in the power supply system. The present invention uses the varistor 71 when the high temperature comes, and when the surface temperature rapidly rises to a preset value, the temperature sensing conjugate 72 can react quickly and melt instantaneously, so that the band 74 is released, so that the The pressing force of the compression spring 73 disappears instantaneously and rises upward, thereby causing displacement of the rod 75, forcing the first contact 421 on the contact spring 42 to be disengaged from the second contact 511, so that the first lug 40 is When the double-bonded metal piece 41 is not deformed and tripped, the second terminal piece 50 can be opened (OFF) with a slight thrust moment.

The varistor 71 disclosed in the above embodiment is one, but is not limited thereto; FIG. 7A is a schematic view showing the use of two parallel-connected varistor 71 and the strap 74 in the present invention, which has the advantage that Increasing the surge absorption function and utilizing the two corresponding surfaces 711 of the two varistor 71a, 71b, when the high voltage comes, the two surface heating temperatures have a temperature that allows the temperature sensing conjugate 72 to react more quickly. Instantly melts and enhances the safety of use. In addition, another way is to connect another varistor pin to the ground line for the simple positive pole and ground protection of the three-wire type circuit, except for the original AC line and the neutral pole. In addition to the wave absorption protection, there is a set of surge absorption protection structures between the positive electrode and the ground electrode. This is also a feasible embodiment and will not be described.

Figure 7B is a schematic view showing the complete protection of the three-wire type circuit of the present invention using three varistor 71a, 71b, 71c and the band 74, which differs from the above embodiment in that the first difference is made by using the position difference. The temperature-sensitive conjugate 72a fixes the first end 741 of the strap 74 between the first varistor 71a and the second varistor 71b, and the second end 742 utilizes the second temperature-sensitive conjugate 72b. The first varistor 71b is fixed between the second varistor 71b and the third varistor 71c; and the three varistors are respectively independently connected between the three lines of the live line, the neutral line and the ground line, thereby achieving An open circuit can be completed when a set of surges exceeds the temperature rise or the lightning strikes any of the electrodes. Similarly, the combination of the position difference and the parallel wiring can also be used to connect the three varistor to the triple swell absorption function as described in the foregoing section, and is used in the embodiment of the two-wire type circuit. 7A and FIG. 7B, it is understood that the varistor 71 built in the interior of the housing 31 of the current overload protection switch can be implemented by one or more configurations, and will not be described again.

FIG. 8 is a front perspective view of a preferred embodiment of the present invention. In this embodiment, the surface of the housing 31 can be provided with a display unit 38 in a state in which the surge absorption and breaking structure 70 is in use, that is, the switch module. The internal temperature sensing splicing 72 has been melted, causing the contact to be tripped. At this time, the display unit 38 can inform the user of the internal state of the switch module 30 by using an element such as an LED bulb or a top block, or The rod 75 pushes the other set of negative contact points to make the synchronous separation into a positive and negative two-wire breaking structure. However, the configuration of the display unit 38 or the negative electrode contact separation structure is the same as that described above, and can be easily accomplished by those having ordinary knowledge, and will not be described again.

9 is a perspective view of the bottom surface of FIG. 8. In this embodiment, the bottom surface of the casing 31 is different from the first lug 40 of the positive input, the second lug 50 of the positive output, and the third lug 60 of the negative input. In addition, a fourth lug 61 as a negative output and a fifth lug 62 as a ground electrode (G) are provided for the ground connection of the electrical connection 712 of the varistor 71 (G) The connection; accordingly, the switch module 30 of the present invention is more complete.

By means of the above-mentioned technical features, the invention solves the problem that the conventional current overload protection switch needs an external temperature fuse and a surge absorber. In the internal space of the current overload protection switch, a surge absorption and breaking structure 70 is skillfully built. When the surge voltage is high, the heat-sensitive varistor 71 and the temperature-sensitive adhesive 72 that can be instantaneously melted are used to loosen the band 74, and the compression spring 73 is used to push the rod member 75 upwardly to disengage the two contacts. Quickly form an open circuit. Therefore, in addition to the current overload protection function, the present invention further has an overvoltage protection and a surge absorption function in the same switch, and has a surge over-circuit design, which is safe for use and convenient to use. Improved efficacy.

In summary, the technical means disclosed in the present invention have the invention patents such as "novelty", "progressiveness" and "available for industrial use", and pray for the patent to encourage the invention. German sense.

The drawings and the descriptions of the present invention are merely preferred embodiments of the present invention, and those skilled in the art, which are subject to the spirit of the present invention, should be included in the scope of the patent application.

30‧‧‧Switch Module
31‧‧‧Shell
32‧‧‧Clamps
33‧‧‧ linkages
34‧‧‧ stop surface
35‧‧‧ positioning surface
36‧‧‧through slot
37‧‧‧The narrow groove
38‧‧‧Display unit
40‧‧‧First lug
41‧‧‧ Double metal sheet
411‧‧‧Free end
42‧‧‧Contact reeds
421‧‧‧ first joint
50‧‧‧second lug
51‧‧‧The last section
511‧‧‧second junction
52‧‧‧ gap
60‧‧‧ Third lug
61‧‧‧fourth lug
62‧‧‧5th lug
70, 71a, 71b, 71c‧‧‧ surge absorption and breaking structure
71‧‧‧ varistor
711‧‧‧ surface
712‧‧‧Electrical connectors
72, 72a, 72b‧‧‧ Temperature conjugate
73‧‧‧Compressed spring
74‧‧‧Belt
741‧‧‧ first end
742‧‧‧ second end
75‧‧‧ rods
751‧‧‧Base

Fig. 1A is a perspective view showing the appearance of a current overload protection switch. Figure 1B is a cross-sectional view of a conventional current overload protection switch. Fig. 2 is a schematic view showing the anti-surge breaking mode of the conventional TW I408717 (i.e., U.S. Patent No. 8,643,462). Figure 3 is a cross-sectional view showing the structure of the switch in an OFF state in accordance with a preferred embodiment of the present invention. 4 is a cross-sectional view of the structure of the preferred embodiment of the present invention showing the switch in an ON state. Figure 4A is a cross-sectional view showing a side view of 4A-4A in Figure 4; Fig. 5 is a view showing the state of use of the present invention, showing that the temperature-sensitive conjugate is dissolved and the band is loosened, and the rod is displaced to form a contact open circuit (OFF). Figure 5A is a cross-sectional view showing a side view of 5A-5A in Figure 5; Figure 6 is an exploded perspective view of the main components of a preferred embodiment of the present invention. Fig. 7A is a schematic view showing the differential wiring of the present invention using two varistor. Fig. 7B is a schematic view showing the use of three varistor in combination with the difference position of the belt of the present invention. Figure 8 is a front perspective view of a preferred embodiment of the present invention. Figure 9 is a perspective view of the bottom surface and terminal of a preferred embodiment of the present invention.

30‧‧‧Switch Module

31‧‧‧Shell

32‧‧‧Clamps

33‧‧‧ linkages

34‧‧‧ stop surface

35‧‧‧ positioning surface

36‧‧‧through slot

37‧‧‧The narrow groove

40‧‧‧First lug

41‧‧‧ Double metal sheet

411‧‧‧Free end

42‧‧‧Contact reeds

421‧‧‧ first joint

50‧‧‧second lug

51‧‧‧The last section

511‧‧‧second junction

52‧‧‧ gap

60‧‧‧ Third lug

70‧‧‧ Surge absorption and breaking structure

71‧‧‧ varistor

711‧‧‧ surface

712‧‧‧Electrical connectors

72‧‧‧ Temperature conjugate

73‧‧‧Compressed spring

74‧‧‧Belt

741‧‧‧ first end

742‧‧‧ second end

75‧‧‧ rods

751‧‧‧Base

Claims (12)

A switch module with a built-in surge absorption and breaking structure comprises: a housing having a pressing block at an upper end thereof, and a first lug, a second lug and a third lug at the bottom end, wherein A first metal piece is connected to the first wire, and a contact spring and a first contact are disposed in the middle of the double metal piece. The upper surface of the second wire is opposite to the first contact. a second contact; a linking member, one end of which is pivotally disposed at the bottom of the pressing block, and the other end of which is coupled with the free end of the contact spring, and the pressing of the pressing block drives the double metal piece and the upper portion thereof The contact spring is deformed, so that the first contact on the contact spring contacts the second contact to form an ON state, and when the current is overloaded, the variability of the double metal piece is deformed due to an increase in temperature. And forming a disconnection (OFF) from the first contact on the contact spring, thereby forming a current overload protection switch; characterized by: a surge absorption and breaking structure, built in In the housing and in the contact Below the sheet, comprising: at least one varistor having an upper and lower surface and a set of electrical connectors; a compression spring disposed on a surface of the varistor; The belt has a first end and a corresponding second end, the strap compresses the compression spring on the varistor, and the first end and the second end are in a correspondingly corresponding form; at least one temperature sensing The joint is glued to the surface of the varistor, and the first end and the second end of the strap are bonded to form an annular body to tighten the compression spring; a rod member, an upper end thereof Located at a bottom surface of the contact spring; thereby, when the first contact is in contact with the second contact, a high voltage is encountered to cause the temperature of the varistor to rise instantaneously higher than the temperature sensitive conjugate a melting value forcing the temperature-sensitive conjugate to melt and release the band, whereby the compression spring is lifted upward, thereby pushing the rod upwardly, forcing the first contact on the contact spring to disengage from the first Two contacts, so that the first lug is not deformed in the double metal piece In the case of the off-state, the second lug can be broken (OFF) with a slight thrust moment. The switch module of the built-in surge absorption and disconnection structure according to claim 1, wherein the temperature sensitive joint comprises: a non-metal heat sensitive substance, a metal low temperature fast-melting metal compound. A composition. The switch module of the built-in surge absorption and breaking structure according to the second aspect of the invention, wherein the band and the temperature sensing joint comprise two different materials, metal and non-metal. The switch module of the built-in surge absorption and disconnection structure according to claim 2, wherein the band and the temperature sensitive joint are the same temperature sensing material. The switch module of the built-in surge absorption and breaking structure according to claim 1, wherein the inner space of the casing is provided with a stop surface and a lateral positioning surface, and the positioning surface is provided for The upper portion of the second lug is placed and positioned. The switch module of the built-in surge absorption and disconnection structure according to the fifth aspect of the invention, wherein the upper portion of the second lug is provided with a notch on a side of the second contact, the positioning surface being opposite to the The position of the notch of the upper section is provided with a perforation for facilitating the penetration of the rod. The switch module of the built-in surge absorption and disconnection structure according to claim 1, wherein the internal space of the casing is provided between the first lug and the second lug. The narrow groove is embedded for positioning on both sides of the varistor. The switch module of the built-in surge absorbing and breaking structure according to claim 1, wherein the lever member is provided with a base, and the base abuts against the top surface of the compression spring. The switch module of the built-in surge absorption and breaking structure according to claim 1, wherein the varistor is one, and the first end and the second end of the strap are connected by a temperature sensing joint. The end is fixed to the surface of the varistor. The switch module of the built-in surge absorption and breaking structure according to claim 1, wherein the varistor has two, and the first end of the strap and the first end of the strap are connected by a temperature sensing joint. The two ends are fixed between the two varistor. The switch module of the built-in surge absorption and disconnection structure according to the first aspect of the patent application, wherein the varistor has three, the temperature-sensitive joint is two, and the first temperature-sensitive joint is used. Fixing the first end of the strap between the first varistor and the second varistor, the second end of the strap being secured to the second varistor by a second temperature splicing Between the third varistor. The switch module of the built-in surge absorption and disconnection structure according to the first aspect of the invention, wherein the surface of the casing further comprises a display unit provided with a state of use of the switch module, and the surface of the casing is provided with one The fourth lug of the negative output and the fifth lug as the ground are used for the ground connection of the electrical connection of the varistor.