CN221669557U - Lightning protection circuit, circuit board and lightning protection socket - Google Patents

Abstract

The application provides a lightning protection circuit, a circuit board and a lightning protection socket, wherein the lightning protection circuit comprises: the voltage-sensitive resistor, the current limiting unit, the first light-emitting diode and the second light-emitting diode; the first end of the piezoresistor is respectively and electrically connected with the input positive electrode of the power strip and the first end of the current limiting unit, the second end of the current limiting unit is respectively and electrically connected with the anode of the first light emitting diode and the cathode of the second light emitting diode, and the second end of the piezoresistor is respectively and electrically connected with the cathode of the first light emitting diode, the anode of the second light emitting diode and the input negative electrode of the power strip. The first light-emitting diode and the second light-emitting diode are arranged as the indicator lamp, and the first light-emitting diode and the second light-emitting diode are in anti-parallel connection, so that when reverse voltage occurs, a corresponding loop can be provided, and the conditions of breakdown and the like are avoided; in addition, the device can work in an alternating current power supply to achieve the purpose of alternating current and direct current, thereby expanding the application scene.

Description

Lightning protection circuit, circuit board and lightning protection socket

Technical Field

The present application relates to the field of electrical technology, and in particular to a lightning protection circuit, a circuit board and a lightning protection socket strip.

Background Art

A power strip (also called a power strip) is a portable power distribution device, usually consisting of a plug and multiple power interfaces. Users can connect the power strip to a wall socket or other power interface through the plug, and then provide power to multiple electrical devices through the multiple power interfaces on the power strip.

Currently, there are power strips with lightning protection functions on the market. This type of power strip usually uses a varistor as the core lightning protection element for lightning protection. The varistor is connected in parallel to the power supply. When a lightning signal appears, the varistor overvoltage is shunted and directed to the ground. Lightning protection power strips are generally equipped with indicator lights for the varistor, which can indicate the corresponding normal or faulty state of the varistor. However, the indicator light solution of existing lightning protection power strips is not effective and has limitations in application scenarios.

Summary of the invention

In view of the deficiencies in the prior art, the present application provides a lightning protection circuit, a circuit board and a socket strip.

In a first aspect, in one embodiment, the present application provides a lightning protection circuit, the lightning protection circuit comprising:

A varistor, a current limiting unit, a first light emitting diode and a second light emitting diode;

The first end of the varistor is electrically connected to the positive pole of the power strip power input and the first end of the current limiting unit, respectively; the second end of the current limiting unit is electrically connected to the anode of the first light-emitting diode and the cathode of the second light-emitting diode, respectively; the second end of the varistor is electrically connected to the cathode of the first light-emitting diode, the anode of the second light-emitting diode and the negative pole of the power strip power input, respectively.

In one embodiment, the varistor comprises a zinc oxide varistor.

In one embodiment, the current limiting unit includes a current limiting resistor.

In one embodiment, the lightning protection circuit further comprises:

Temperature protection unit;

The first end of the temperature protection unit is electrically connected to the cathode of the first light-emitting diode, the anode of the second light-emitting diode and the second end of the varistor respectively, and the second end of the temperature protection unit is electrically connected to the negative electrode of the power strip power input;

The temperature protection unit disconnects when the varistor overheats.

In one embodiment, the temperature protection unit comprises a temperature fuse.

In one embodiment, the lightning protection circuit further comprises:

Switching unit;

The first end of the switch unit is electrically connected to the positive pole of the power strip power input, and the second end of the switch unit is electrically connected to the first end of the current limiting unit.

In one embodiment, the switch unit comprises a mechanical switch.

In a second aspect, in one embodiment, the present application provides a circuit board integrated with the lightning protection circuit in any of the above embodiments.

In one embodiment, a lightning protection circuit in one of the above embodiments is integrated;

On the circuit board, the first light emitting diode and the second light emitting diode are arranged on one side of the varistor, and the temperature fuse is arranged on the other side of the varistor.

In a third aspect, in one embodiment, the present application provides a lightning protection power strip, comprising the circuit board in any one of the above embodiments.

Through the above-mentioned lightning protection circuit, circuit board and socket strip, a first light-emitting diode and a second light-emitting diode are set as indicator lights. Since the first light-emitting diode and the second light-emitting diode are anti-parallel connected, when a reverse voltage occurs, a corresponding circuit can be provided to avoid breakdown and the like. In addition, it can also work in an AC power supply to achieve the purpose of AC and DC dual use, thereby expanding the application scenarios of the indicator lights on the lightning protection socket strip.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

FIG1 is a schematic structural diagram of a lightning protection circuit provided by an embodiment of the present application;

FIG2 is a schematic structural diagram of a lightning protection circuit including a switch unit and a temperature protection unit provided by an embodiment of the present application;

FIG3 is a schematic diagram of a specific circuit implementation of a lightning protection circuit provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of the structure of a circuit board provided in one embodiment of the present application.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In the present application, the word "exemplary" is used to mean "used as an example, illustration or description". Any embodiment described as "exemplary" in the present application is not necessarily interpreted as being more preferred or more advantageous than other embodiments. In order to enable any person skilled in the art to implement and use the present application, the following description is provided. In the following description, details are listed for the purpose of explanation. It should be understood that one of ordinary skill in the art will recognize that the present application can be implemented without using these specific details. In other examples, well-known structures and processes will not be elaborated in detail to avoid unnecessary details that make the description of the present application obscure. Therefore, the present application is not intended to be limited to the embodiments shown, but is consistent with the broadest range of principles and features disclosed in the present application.

In a first aspect, as shown in FIG. 1 , in one embodiment, the present application provides a lightning protection circuit, which includes a varistor MOV1 , a current limiting unit 101 , a first light emitting diode LED1 , and a second light emitting diode LED2 .

The first end of the varistor MOV1 is electrically connected to the positive pole IN+ of the power strip power input and the first end of the current limiting unit 101, respectively. The second end of the current limiting unit 101 is electrically connected to the anode of the first light-emitting diode LED1 and the cathode of the second light-emitting diode LED2, respectively. The second end of the varistor MOV1 is electrically connected to the cathode of the first light-emitting diode LED1, the anode of the second light-emitting diode LED2 and the negative pole IN- of the power strip power input.

Among them, the varistor MOV1 is the core component of lightning protection. When the power strip introduces a lightning signal, the voltage amplitude of the lightning signal is relatively high, exceeding the threshold voltage of the varistor MOV1, thereby rapidly reducing the resistance of the varistor MOV1, and then shunting the overvoltage to the ground, avoiding damage to the rear-end electrical equipment and playing a protective role.

Among them, the varistor MOV1 may also be damaged during use, such as short circuit failure. Specifically, when the varistor MOV1 is subjected to excessive voltage shock or long-term overvoltage, it may cause the varistor MOV1 to burn out or short-circuit, causing it to lose its normal resistance characteristics and no longer be able to play the role of overvoltage protection. If the short circuit failure of the varistor MOV1 is not discovered in time, there will be a major safety hazard for the electrical equipment at the back end due to the long-term lack of lightning protection.

To address the above problems, this embodiment provides a first light-emitting diode LED1 and a second light-emitting diode LED2 respectively connected in parallel with the varistor MOV1. When the varistor MOV1 is in a normal state or in a short-circuit fault state, the first light-emitting diode LED1 and the second light-emitting diode LED2 can provide different indications.

Specifically, when the power supply of the socket is direct current, when the varistor MOV1 is in a short-circuit fault state, the first light-emitting diode LED1 and the second light-emitting diode LED2 are both short-circuited, and the first light-emitting diode LED1 and the second light-emitting diode LED2 are not bright; when the varistor MOV1 is in a normal state, the first light-emitting diode LED1 and the second light-emitting diode LED2 are not short-circuited. Since direct current is connected, only the first light-emitting diode LED1 is bright, while the second light-emitting diode LED2 is not bright.

In the DC scenario, the second light-emitting diode LED2 serves the purpose of preventing reverse pressure. When reverse pressure occurs in the circuit and the voltage amplitude is high (exceeding the breakdown voltage of the light-emitting diode), if there is only the first light-emitting diode LED1, it is easy to be broken down and damaged, resulting in failure of the indication function. In this embodiment, the second light-emitting diode LED2 connected in anti-parallel can provide a corresponding circuit when reverse pressure occurs, so that the reverse pressure will not break down the first light-emitting diode LED1. In other embodiments, a Zener diode connected in series in the same direction as the first light-emitting diode LED1 can also be directly set, and the high breakdown voltage of the Zener diode can be used to protect the first light-emitting diode LED1, but the Zener diode is more expensive and larger in size. In addition to being able to protect the first light-emitting diode LED1 from reverse pressure, the second light-emitting diode LED2 can also indicate reverse pressure. When reverse pressure occurs, current passes through the second light-emitting diode LED2, making the second light-emitting diode LED2 light up. Combined with the type of power strip power supply, users can be informed of the current reverse pressure.

Specifically, when the power supply of the socket is AC, when the varistor MOV1 is in a short-circuit fault state, the first light-emitting diode LED1 and the second light-emitting diode LED2 are both short-circuited, and the first light-emitting diode LED1 and the second light-emitting diode LED2 are not lit; when the varistor MOV1 is in a normal state, the first light-emitting diode LED1 and the second light-emitting diode LED2 are not short-circuited, and since AC power is connected, the first light-emitting diode LED1 and the second light-emitting diode LED2 are both lit.

In addition, the first light-emitting diode LED1 and the second light-emitting diode LED2 can serve as indicator lights for the power strip in addition to the indicator lights for the varistor MOV1. Specifically, when there is a DC power input, only the first light-emitting diode LED1 is on, and when there is an AC power input, both the first light-emitting diode LED1 and the second light-emitting diode LED2 are on.

The current limiting unit 101 is used to limit the current flowing through the first light emitting diode LED1 and the second light emitting diode LED2, so that the first light emitting diode LED1 and the second light emitting diode LED2 operate within a safe current range to avoid overcurrent and damage to the first light emitting diode LED1 and the second light emitting diode LED2. In this embodiment, the current limiting unit 101 can be specifically a current limiting diode and a current limiting field effect transistor (MOSFET) and other components.

In a DC circuit, a diode can limit current by being reverse biased, a property known as reverse breakdown voltage. When the reverse voltage exceeds the reverse breakdown voltage of the diode, the diode will begin to conduct and limit the current passing through. This property allows the diode to be used for long-term current limiting protection.

Field effect transistors can achieve precise current limiting function in the circuit by properly controlling voltage and current, and also have the characteristics of low power consumption and fast response.

Through the above-mentioned lightning protection circuit, the first light-emitting diode and the second light-emitting diode are set as indicator lights. Since the first light-emitting diode and the second light-emitting diode are anti-parallel connected, when a reverse voltage occurs, a corresponding circuit can be provided to avoid breakdown and the like; in addition, it can also work in an AC power supply to achieve the purpose of AC and DC dual use.

In one embodiment, the varistor comprises a zinc oxide varistor.

Among them, the zinc oxide varistor is composed of zinc oxide and other additives and has nonlinear resistance characteristics.

Characteristics of zinc oxide varistors include fast response time, high energy absorption capability, and a wide operating temperature range.

Fast response time: Zinc oxide varistors can respond to voltage changes within nanoseconds and transform into a low resistance state.

High energy absorption capability: Zinc oxide varistors can absorb large amounts of energy, protecting circuits from overvoltage damage.

Wide operating temperature range: Zinc oxide varistors are suitable for a wide temperature range and can usually operate normally between -40℃ and +85℃.

In other embodiments, other varistors besides zinc oxide varistors may also be used, such as indium tin oxide varistors (Indium Tin Oxide Varistors, ITOV for short) and multilayer ceramic varistors (Multilayer Ceramic Varistors, MCV for short).

Among them, the model of the zinc oxide varistor can be 20D391, which has a breakdown voltage of 390V and a breakdown current of 15000A. Compared with the 14D varistor with a breakdown current of 8000A, it is larger in size, but can provide a flow capacity and energy tolerance that is nearly twice that of 14D.

The current carrying capacity is also called the flow rate, which refers to the maximum pulse (peak) current value allowed to pass through the varistor under the specified conditions (applying the standard impulse current at the specified time interval and number of times). The so-called current carrying capacity, that is, the peak value of the maximum pulse current, is the maximum pulse current value when the change of the varistor voltage does not exceed ±10% for the specified impulse current waveform and the specified number of impulse currents under the condition of an ambient temperature of 25°C.

Energy tolerance refers to the maximum energy absorbed by the varistor when a specified pulse energy waveform (such as a 10/1000μs waveform) is applied. The symbol is E and the unit is J (Joule). The larger the diameter of the varistor, the greater its energy tolerance and the greater the impact current resistance.

As shown in FIG. 2 , in one embodiment, the lightning protection circuit further includes a temperature protection unit 102 .

The first end of the temperature protection unit 102 is electrically connected to the cathode of the first light-emitting diode LED1, the anode of the second light-emitting diode LED2 and the second end of the varistor MOV1 respectively, and the second end of the temperature protection unit 102 is electrically connected to the negative input electrode IN- of the power strip.

The temperature protection unit 102 is disconnected when the varistor MOV1 is overheated.

Among them, when the varistor MOV1 is in a short-circuit fault state, since its internal resistance becomes very small, the current will increase significantly, causing the varistor MOV1 to generate a large amount of heat energy. This heat energy cannot be dissipated in time, causing the temperature of the varistor MOV1 to gradually increase. If the varistor MOV1 is always in a short-circuit state, the temperature may continue to rise until it reaches a temperature that burns or causes other faults. In addition, the varistor MOV1 will form a local high-temperature area after a short-circuit fault, which may burn the surrounding circuit components and cause more serious damage. Therefore, in view of this situation, this embodiment sets a temperature protection unit 102, which can disconnect the circuit where the varistor MOV1 is located after a short-circuit fault occurs in the varistor MOV1.

Specifically, in the present embodiment, the temperature protection unit 102 may be a fuse. When the varistor MOV1 is in a short-circuit fault state, the current will increase significantly due to its internal resistance becoming very small. Similarly, the current of the fuse connected in series will also increase, causing the fuse to heat up. When the temperature reaches its temperature threshold (i.e., the melting temperature), the fuse will disconnect, thereby disconnecting the circuit where the varistor MOV1 is located, thereby avoiding continuous high temperature and protecting other devices.

As shown in FIG. 2 , in one embodiment, the lightning protection circuit further includes a switch unit 103 .

A first end of the switch unit 103 is electrically connected to the positive input electrode IN+ of the power strip, and a second end of the switch unit 103 is electrically connected to a first end of the current limiting unit 101 .

Among them, the switch unit 103 is used to control the input of the power strip. When the switch unit 103 is in the on state, the power strip can be input into the lightning protection circuit and output to the rear-end electrical equipment after passing through the power strip output terminals OUT+ and OUT-.

As shown in FIG. 3 , in one embodiment, the switch unit includes a mechanical switch K1 .

Among them, mechanical switches are a common electronic component that is used to open or close the path of current in a circuit. Mechanical switches usually switch circuits based on physical contact. According to the classification of switch methods, they can be further divided into button switches, slide switches, and rotary switches.

A push button switch is typically a switch that can be pressed or released to open or close a circuit by pressing the button.

A slide switch has a slider that opens or closes a circuit by sliding it left or right.

A rotary switch is a knob-type switch that selects different circuit connections or functions by rotating the switch.

As shown in FIG. 3 , in one embodiment, the current limiting unit includes a current limiting resistor R1 .

Among them, compared with other current limiting components, the current limiting resistor R1 has the advantages of simplicity and reliability, low cost, good thermal stability, high reliability, and easy design and application.

Simple and reliable: The current limiting resistor R1 is a simple passive component with no active or moving parts, making it very reliable. They do not require external energy or control signals to operate and are not susceptible to external interference.

Low cost: Compared with some current limiting components that require additional control circuits or energy, the cost of the current limiting resistor R1 is usually low, which can reduce the overall circuit cost.

Good thermal stability: Within the appropriate power range, the thermal stability of the current limiting resistor R1 is usually good, and the current limit value is not easily changed due to temperature changes.

High reliability: The current limiting resistor R1 usually has a long life and high reliability. As long as it is used within the specified power range, its performance will be relatively stable.

Easy to design and apply: The design and application of the current limiting resistor R1 is relatively simple. Usually, it only requires selecting a suitable resistance value and connecting it. No complex control circuit or additional energy supply is required.

As shown in FIG. 3 , in one embodiment, the temperature protection unit includes a temperature fuse RT1 .

Among them, the temperature fuse RT1 is a device based on temperature protection. It is usually made of a thermosensitive material. When the ambient temperature rises to the trigger temperature, it will quickly disconnect the circuit to prevent the over-temperature from damaging the electrical equipment. The temperature fuse RT1 can sense the ambient temperature more intuitively, so that it can disconnect the circuit of the varistor MOV1 more promptly when the temperature is over.

In a second aspect, in one embodiment, the present application provides a circuit board integrated with the lightning protection circuit in any of the above embodiments.

Through the above-mentioned circuit board, a first light-emitting diode and a second light-emitting diode are set as indicator lights. Since the first light-emitting diode and the second light-emitting diode are anti-parallel connected, when a reverse voltage occurs, a corresponding circuit can be provided to avoid breakdown and the like; in addition, it can also work in an AC power supply to achieve the purpose of AC and DC dual use.

In one embodiment, a lightning protection circuit in one of the above embodiments is integrated.

Among them, it mainly refers to a lightning protection circuit that integrates a first light-emitting diode, a second light-emitting diode, a varistor and a temperature fuse.

As shown in FIG. 4 , on the circuit board, the first light emitting diode and the second light emitting diode (ie, the light emitting diode module LED) are arranged on one side of the varistor MOV1 , and the temperature fuse RT1 is arranged on the other side of the varistor MOV1 .

With the above circuit board layout, the effect is better.

As shown in FIG. 4 , when the lightning protection circuit further includes a current limiting resistor R1 , the current limiting resistor R1 is distributed above the light emitting diode module LED on the circuit board.

In a third aspect, in one embodiment, the present application provides a lightning protection power strip, comprising the circuit board in any one of the above embodiments.

Through the above-mentioned power strip, the first light-emitting diode and the second light-emitting diode are set as indicator lights. Since the first light-emitting diode and the second light-emitting diode are anti-parallel connected, when a reverse voltage occurs, a corresponding circuit can be provided to avoid breakdown and the like; in addition, it can also work in an AC power supply to achieve the purpose of AC and DC dual use.

In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, please refer to the detailed description of other embodiments above, and will not be repeated here.

The above is a detailed introduction to a lightning protection circuit, a circuit board and a lightning protection socket provided by the present application. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea; at the same time, for technical personnel in this field, according to the idea of the present application, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims (10)

1. A lightning protection circuit, characterized in that the lightning protection circuit comprises: A varistor, a current limiting unit, a first light emitting diode and a second light emitting diode; The first end of the varistor is electrically connected to the positive pole of the power strip power input and the first end of the current limiting unit, respectively; the second end of the current limiting unit is electrically connected to the anode of the first light-emitting diode and the cathode of the second light-emitting diode, respectively; the second end of the varistor is electrically connected to the cathode of the first light-emitting diode, the anode of the second light-emitting diode and the negative pole of the power strip power input, respectively. 2 . The lightning protection circuit according to claim 1 , wherein the varistor comprises a zinc oxide varistor. 3 . The lightning protection circuit according to claim 1 , wherein the current limiting unit comprises a current limiting resistor. 4. The lightning protection circuit according to claim 1, characterized in that the lightning protection circuit further comprises: Temperature protection unit; The first end of the temperature protection unit is electrically connected to the cathode of the first light-emitting diode, the anode of the second light-emitting diode and the second end of the varistor respectively, and the second end of the temperature protection unit is electrically connected to the negative input electrode of the power strip power supply; The temperature protection unit is disconnected when the varistor is overheated. 5 . The lightning protection circuit according to claim 4 , wherein the temperature protection unit comprises a temperature fuse. 6. The lightning protection circuit according to claim 1, characterized in that the lightning protection circuit further comprises: Switching unit; The first end of the switch unit is electrically connected to the positive input electrode of the power strip, and the second end of the switch unit is electrically connected to the first end of the current limiting unit. 7 . The lightning protection circuit according to claim 6 , wherein the switch unit comprises a mechanical switch. 8. A circuit board, characterized by comprising the lightning protection circuit according to any one of claims 1 to 7. 9. The circuit board according to claim 8, characterized in that the circuit board also includes a temperature fuse; wherein the first light-emitting diode and the second light-emitting diode are arranged on one side of the varistor, and the temperature fuse is arranged on the other side of the varistor. 10. A lightning protection socket strip, comprising the circuit board according to claim 8.