Self-heating discharge gap

Abstract

The invention relates to a self-heating discharge gap which comprises a pair of electrodes, and a preset gap distance, namely a gap, is kept between the two electrodes; the cavity is a component made of an insulating material and arranged on the periphery of the gap, and the cavity abuts against the pair of electrodes respectively; and the heating structure is arranged on the outer surface or the inner surface of the discharge gap or in the discharge gap. According to the self-heating discharge gap, when pulse current exists, voltage drop generated when part of current flows through the coating is higher than breakdown voltage in the gap so that the gap can be broken down, and at the moment, most of the current flows through the gap. When the surge protection device is influenced by power frequency overvoltage exceeding pressure-sensitive voltage, no matter whether the voltage can cause MOV thermal breakdown or not, current can flow through the discharge gap coating, because the voltage is lower than starting voltage after MOV series connection with a gap, the coating can be heated to the temperature for fusing a tin soldering point in a short time only by milliampere-level current, so that the temperature of the metal oxide semiconductor can be reduced, and the service life of the metal oxide semiconductor can be prolonged. Therefore, the surge protection device is separated from the power line.

Description

Technical Field

[0001] The present invention relates to the technical field related to surge protectors, and in particular to a self-heating discharge gap. Background Art

[0002] There are two main ways for traditional surge protectors to disconnect from the power line when a fault occurs: 1. Using MOV to generate leakage current under line AC overvoltage. The zinc oxide semiconductor material will heat up under this current. As the current increases, the MOV heats up further and is transmitted to the low-temperature welding point through its metal pins. When the melting point of the low-temperature solder is reached, the connection is pulled apart from the power connection line by the spring, thereby disconnecting the surge protector from the power line. 2. MOV is combined with a thermal fuse. When the power line is over-voltage for a long time, the MOV heats up and is transmitted to the thermal fuse, which blows internally to disconnect from the power line.

[0003] The above two methods are based on the premise that MOV can generate heat normally, but MOV also has a failure mode of "thermal breakdown". Under instantaneous large current, MOV is thermally broken down to form a low-resistance channel. At this time, the industrial frequency current flowing through MOV will not generate heat or the heat generated is insufficient, so it cannot be disconnected from the power line.

[0004] Therefore, the defects of the prior art are as follows: The existing method of disconnecting the surge protector from the power line when it fails is to use the fact that when the leakage current flows through the MOV, the MOV will generate heat. When the leakage current reaches a certain value, the MOV accumulates heat enough to melt the low-temperature solder point connected to the power line or cause the temperature fuse connected in series with the MOV to melt, thereby achieving the purpose of disconnecting the surge protector from the power line.

[0005] However, when the MOV is thermally broken down, a low-resistance current channel will be formed at the breakdown point. The MOV will not continue to generate heat or will generate insufficient heat. The welding point or thermal fuse will not melt, and the surge protector cannot be disconnected from the power line. Summary of the invention

[0006] The purpose of the present invention is to solve at least one of the deficiencies of the prior art and to provide a self-heating discharge gap.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions: Specifically, a self-heating discharge gap is proposed, comprising: A pair of electrodes, wherein a preset gap distance is maintained between the two electrodes, i.e., a gap is provided; A cavity, which is an insulating material component, is arranged at the periphery of the gap, and the cavity is respectively in contact with a pair of the electrodes; The heating structure is arranged on the outer surface, inner surface or inside the cavity.

[0008] Further, specifically, The distance of the gap meets a preset range.

[0009] Further, specifically, The cavity is a ceramic component.

[0010] Further, specifically, the heating structure includes a heating coating formed by any one or more combinations of graphene carbon paste coating, PTC coating, and MCH coating.

[0011] Further, specifically, the heating structure includes a high-power resistor and an MCH heating element. The high-power resistor is connected in series with the MCH heating element and then connected in parallel to the discharge gap.

[0012] The present invention proposes a self-heating discharge gap, which is made by coating a heating coating on the outer surface, inner surface or body of the discharge gap, and then connecting the gap in series with an MOV. When there is a pulse current, since the coating has a certain resistance value, a voltage drop higher than the breakdown voltage inside the gap is generated when part of the current flows through the coating, so the gap is broken down, and the resistance value inside the gap after the breakdown will drop to almost zero. At this time, most of the current will flow through the gap instead of the coating. When the surge protector is affected by an industrial frequency overvoltage exceeding the varistor voltage, regardless of whether the voltage will cause thermal breakdown of the MOV, the current will flow through the discharge gap coating, because the voltage is lower than the starting voltage after the MOV is connected in series with the gap, and the coating only needs a milliampere current to heat up to the temperature of melting the solder joint in a short time, thereby achieving the purpose of disconnecting the surge protector from the power line. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The above and other features of the present disclosure will become more apparent by describing in detail the embodiments shown in the accompanying drawings. The same reference numerals in the accompanying drawings of the present disclosure represent the same or similar elements. Obviously, the accompanying drawings described below are only some embodiments of the present disclosure. For those skilled in the art, other accompanying drawings can be obtained based on these accompanying drawings without creative work. In the accompanying drawings: Figure 1 The figure shows a structural principle diagram of a cross section of an embodiment of a self-heating discharge gap of the present invention; Figure 2 Shown is a structural principle diagram of another embodiment of a self-heating discharge gap of the present invention; Figure 3 Shown is a cross-sectional schematic diagram from a 3D perspective of an embodiment of a heat-generating coating of a self-heating discharge gap of the present invention. DETAILED DESCRIPTION

[0014] The following will be combined with the embodiments and drawings to clearly and completely describe the concept, specific structure and technical effects of the present invention, so as to fully understand the purpose, scheme and effect of the present invention. It should be noted that the embodiments in this application and the features in the embodiments can be combined with each other without conflict. The same reference numerals used throughout the drawings indicate the same or similar parts.

[0015] The present invention provides a self-heating discharge gap, comprising: A pair of electrodes, wherein a preset gap distance is maintained between the two electrodes, i.e., a gap is provided; A cavity, which is an insulating material component, is arranged at the periphery of the gap, and the cavity is respectively in contact with a pair of the electrodes; The heating structure is arranged on the outer surface, inner surface or inside the cavity.

[0016] As a preferred embodiment of the present invention, specifically, The distance of the gap meets a preset range.

[0017] In this preferred embodiment, the gap is controlled within the range of industry standards to meet the actual application scenarios of the present invention.

[0018] Specifically, The cavity is a ceramic component.

[0019] In this preferred embodiment, the cavity is set to be a ceramic material, which can be well adapted to the application scenario of the present invention. Of course, other insulating materials that can meet the actual application scenario of the present invention are also possible.

[0020] Reference Figure 1 as well as Figure 3 , Example 1, specifically, the heating structure includes a heating coating formed by any one or more combinations of graphene carbon paste coating, PTC coating, and MCH coating.

[0021] In the present embodiment 1, a heating structure is coated on the outer surface or inner surface or body of the discharge gap. The heating structure can be any one or more combinations of graphene carbon paste coating, PTC coating, and MCH coating to form a self-heating discharge gap, and then the gap is connected in series with the MOV. When there is a pulse current, since the coating has a certain resistance value, a voltage drop higher than the breakdown voltage inside the gap is generated when part of the current flows through the coating, so the gap is broken down, and the resistance value inside the gap after the breakdown will drop to almost zero. At this time, most of the current will flow through the gap instead of the coating. When the surge protector is affected by an industrial frequency overvoltage exceeding the varistor voltage, regardless of whether the voltage will cause thermal breakdown of the MOV, the current will flow through the discharge gap coating, because the voltage is lower than the starting voltage after the MOV is connected in series with the gap, and the coating only needs milliampere current to heat to the temperature of melting the solder joint in a short time, so as to achieve the purpose of disconnecting the surge protector from the power line.

[0022] Reference Figure 2 , Example 2, specifically, the heating structure includes a high-power resistor and an MCH heating element, the high-power resistor is connected in series with the MCH heating element, and then connected in parallel to the discharge gap, wherein the high-power resistor refers to a resistor with higher power than a conventional resistor.

[0023] In this embodiment 2, as an alternative to embodiment 1, a high-power resistor can be connected in series with the MCH heating sheet and then connected in parallel to the discharge gap. However, this has the following disadvantages: 1. The resistors and heaters must be matched according to different voltages; 2. The component cost is high; 3. The assembly is large in size.

[0024] Although the description of the present invention has been quite detailed and specifically describes several described embodiments, it is not intended to be limited to any of these details or embodiments or any particular embodiment, but should be regarded as providing a broad possible interpretation of these claims in view of the prior art by reference to the appended claims, thereby effectively covering the intended scope of the present invention. In addition, the above description of the present invention is based on the embodiments foreseeable by the inventor, and its purpose is to provide a useful description, and those non-substantial changes to the present invention that have not yet been foreseen may still represent equivalent changes to the present invention.

[0025] The above is only a preferred embodiment of the present invention. The present invention is not limited to the above implementation. As long as the technical effect of the present invention is achieved by the same means, it should belong to the protection scope of the present invention. Within the protection scope of the present invention, its technical scheme and / or implementation method can have various modifications and changes.

Claims

1. A self-heating discharge gap, characterized in that: include: A pair of electrodes, wherein a preset gap distance is maintained between the two electrodes, i.e., a gap is provided; A cavity, which is an insulating material component, is arranged at the periphery of the gap, and the cavity is respectively in contact with a pair of the electrodes; The heating structure is arranged on the outer surface, inner surface or inside the cavity.

2. A self-heating discharge gap according to claim 1, characterized in that: Specifically, The distance of the gap meets a preset range.

3. The discharge gap external thermal release device according to claim 1, characterized in that: Specifically, The cavity is a ceramic component.

4. A self-heating discharge gap according to claim 1, characterized in that: Specifically, the heating structure includes a heating coating formed by any one or more combinations of graphene carbon paste coating, PTC coating, and MCH coating.

5. The self-heating discharge gap according to claim 1, characterized in that: Specifically, the heating structure includes a high-power resistor and an MCH heating element. The high-power resistor is connected in series with the MCH heating element and then connected in parallel to the discharge gap.

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