CN102263407A - High voltage protection device - Google Patents

Abstract

The invention provides a high voltage protector which comprises a casing, a protection assembly provided in the casing, a circuit board and a screw made of a conductive material. The protection assembly is electrically connected with the circuit board. The circuit board is provided with a pad which comprises a pilot hole and a conduction region. The conduction region is arranged in the periphery of the pilot hole and is electrically connected with the protection assembly. Through the pilot hole the screw is detachably fixed in the casing. When the screw is assembled in the casing, the screw is electrically connected with the conduction region. The high voltage protector is easy to test and simple in assembly.

Description

High voltage protection device

technical field

The invention relates to a high-voltage protection device, in particular to a high-voltage protection device for AC power supply products.

Background technique

In order to prevent lightning strikes, lightning strike protection components are usually installed in the case of AC power products. When lightning strikes generate a momentary high voltage, the lightning strike protection components will start and provide a grounding path to directly conduct high voltage energy to the circuit board. ground terminal to avoid damage to the internal components of the product. On the other hand, most AC power products need to be tested according to safety regulations to ensure that the product will not have leakage. At this time, in order to prevent the lightning strike protection component from being triggered by the instantaneous high voltage during the test, which would cause the test to fail, it is usually necessary to take out the lightning strike protection component before the test, and reinstall the lightning strike protection component in the original circuit after the test. Obviously, this approach will increase the difficulty of assembling the product and prolong the manufacturing cycle of the product.

Contents of the invention

In view of the above circumstances, it is necessary to provide a high-voltage protection device that is simple to assemble and easy to test.

A high-voltage protection device, which includes a casing, a protective component arranged in the casing, a circuit board and a screw made of conductive material, the protective component is electrically connected to the circuit board, and the circuit There is a pad on the board, the pad includes an assembly hole and a conductive area, the conductive area is set on the outer periphery of the assembly hole and electrically connected with the protective component, the screw is detachably fixed on the casing through the assembly hole , when the screw is assembled on the casing, the screw is electrically connected to the conductive area.

Compared with the prior art, the high voltage protection device is detachably electrically connected between the casing and the conductive area on the pad by using a screw. When the screw is removed, the protective component and the casing are in an open circuit state for testing; after the test is completed, the screw is installed to establish an electrical connection between the protective component and the casing through the screw as a conductive path, and then the instantaneous The high-voltage current is diverted to the ground to avoid damage to the equipment. The high voltage guard is easy to test and easy to assemble.

Description of drawings

Fig. 1 is a schematic circuit diagram of a high voltage protection device in a preferred embodiment of the present invention;

Fig. 2 is a schematic diagram of a pad in a preferred embodiment of the present invention;

Fig. 3 is a cross-sectional view of the assembly relationship between the screw, the circuit board and the casing according to the preferred embodiment of the present invention.

Explanation of main component symbols

High voltage protection device 100

FireWire L

Zero Line N

Chassis 10

Copper pillars 12

circuit board 20

Ground terminal 22

Pads 24

Mounting hole 242

Insulation area 246

Conductive zone 248

Protective components 30

Resistors R1, R2, R3

screw 40

Screw 42

Nut 44

Detailed ways

Please refer to FIG. 1 , the embodiment of the present invention provides a high voltage protection device 100, which can be applied to various AC power products, such as power distribution cabinets (Power Distribution Unit, PDU). The high voltage protection device 100 includes a casing 10 , a live wire L (live fire), a neutral line N (neutral line), a circuit board 20 , a plurality of protection components 30 and a screw 40 . The live wire L, the neutral wire N, the circuit board 20 , the protection component 30 and the screw 40 are all installed in the casing 10 .

The casing 10 can be a part of the casing of the AC power supply product, and it is in direct contact with the ground to provide a current grounding path for the high voltage protection device 100 . A hollow copper column 12 is welded on the inner wall of the casing 10, and the copper column 12 adopts an internal thread design.

The live line L and the neutral line N are used to provide a 220V AC power path for the high voltage protection device 100 .

Please refer to FIG. 2 . In this embodiment, the thickness of the circuit board 20 is 1.6 mm, and a ground terminal 22 and a welding pad 24 are provided on one surface thereof. The pad 24 is opposite to the copper pillar 12 , and the pad 24 includes a mounting hole 242 , a ring-shaped insulating area 246 , and a ring-shaped conductive area 248 . The mounting hole 242 is used for mounting the screw 40 . The insulating area 246 is disposed on the periphery of the assembly hole 242 , and the insulating area 246 is a clean white area without any conductors disposed thereon. The conductive region 248 can be formed by pouring copper, which is disposed on the outer periphery of the insulating region 246 and electrically connected to the ground terminal 22 . Usually, the current path from the conductive area 248 to the copper pillar 12 can be defined as a safety distance required by safety regulations.

In this embodiment, the protection component 30 includes three existing resistors R1, R2 and R3. The characteristics of the resistors R1, R2 and R3 are: when a momentary high voltage (such as a lightning strike) is generated, the resistance will decrease rapidly. Poly falls, so that the current flows through the casing 10 into the ground. The resistor R1 is electrically connected between the live wire L and the neutral wire N, and the resistors R2 and R3 are respectively electrically connected between the live wire L and the ground terminal 22 and between the neutral wire N and the ground terminal 22 .

The screw 40 is made of conductive material (such as metal), and its specification can be determined according to the actual withstand voltage. The screw 40 includes a screw 42 and a nut 44 integrally disposed. The outer periphery of the screw rod 42 is provided with external threads to pass through the assembly hole 242 and be locked in the copper post 12 . The nut 44 is in contact with the conductive area 248 so that the protective component 30 , the screw 40 and the casing 10 form a current loop.

Please refer to Fig. 3, the following is an example to illustrate the basis for selecting the specifications of the screw 40. Usually, for products using 220V AC power supply, the AC test voltage during the safety standard test is 1.5KV, and the converted safety distance is about 2.5mm. The width of the ring defining the insulating region 246 is R, the thickness of the circuit board 20 is B, the diameter of the screw 42 is D, and the radial length of the nut 44 is M. From R+B=2.5mm, it can be known that R=2.5mm-1.6mm=0.9mm. The condition for the nut 44 to be in contact with the conductive region 248 is M>(D+2×R). Usually, a screw 40 with a screw diameter of about 3 mm and a radial length of the nut of about 5-7 mm can meet the above conditions.

When the high voltage protection device 100 is tested for safety standards, the screw 40 is not installed first. At this time, since the protection component 30 and the casing 10 do not form a current loop, even if there is an instantaneous high voltage, the resistance value of the protection component 30 will change. It will not affect the characteristics of other internal components, so it will not affect the test results. After the test is completed, the screw 40 is assembled on the circuit board 20 and the casing 10, and the nut 44 is in contact with the conductive area 248, so that the protective component 30 is electrically connected to the casing 10. When there is an instantaneous high voltage such as a lightning strike When generated, the current will be grounded through the protective component 30, the screw 40 and the casing 10, thereby preventing damage to AC power products caused by lightning strikes and the like.

It can be understood that in the present invention, a fixing hole for assembling the screw 40 can also be directly opened on the casing 10, and the copper post 12 can be omitted at this time.

In the present invention, a screw 40 is assembled between the protective component 30 and the casing 10 , and the screw 40 is in contact with the conductive area 248 , so as to establish an electrical connection between the casing 10 and the protective component 30 . During the test, the screw 40 is taken out to ensure the accuracy of the test. After the test is completed, install the screw 40, so that the AC power supply product has the function of protecting against instantaneous high voltage. The high voltage protection device 100 does not need to dismantle the protection component 30 in the circuit when testing, and is easy to test and easy to assemble.

Claims (8)

1. high-voltage protection device, it comprises a casing and is located at this casing interior a guard assembly and a circuit board, this guard assembly and circuit board electrically connect, it is characterized in that: described circuit board is provided with a pad, described pad comprises a pilot hole and a conduction region, this conduction region is located at the pilot hole periphery and is electrical connected with guard assembly, described high-voltage protection device also comprises a screw that adopts electric conducting material to make, described screw removably is fixed on the casing by pilot hole, when described screw was assemblied on the casing, described screw and conduction region were electrical connected.

2. high-voltage protection device as claimed in claim 1 is characterized in that: described pad also comprises an insulation layer, and described insulation layer is located between pilot hole and the conduction region.

3. high-voltage protection device as claimed in claim 1 is characterized in that: described circuit board is provided with an earth terminal, and described earth terminal and conduction region are electrical connected.

4. high-voltage protection device as claimed in claim 1 is characterized in that: assembling one bronze medal post on the described casing, described copper post cooperates with screw thread.

5. high-voltage protection device as claimed in claim 1 is characterized in that: described screw comprises a screw rod and a nut, and described screw rod passes pilot hole and is locked in the copper post, and described nut contacts with conduction region.

6. high-voltage protection device as claimed in claim 2 is characterized in that: described insulation layer and conduction region are circular, and described nut radical length is greater than the width sum of screw diameter and twice insulation layer.

7. high-voltage protection device as claimed in claim 1, it is characterized in that: described high-voltage protection device also comprises a live wire and a zero line, described guard assembly comprises three resistance, and described three resistance are respectively between electric connection and live wire and zero line, live wire and earth terminal and zero line and the earth terminal.

8. high-voltage protection device as claimed in claim 1 is characterized in that: described conduction region forms by covering copper.

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