CN217388224U

CN217388224U - Low residual voltage high reliability lightning protection circuit

Info

Publication number: CN217388224U
Application number: CN202122979796.8U
Authority: CN
Inventors: 肖俊承; 王一龙; 韩燕�; 石从怀; 田卫红; 廖日云
Original assignee: Foshan Yigeer Electronics Co ltd; Eaglerise Electric and Electronic China Co Ltd; Foshan Shunde Eaglerise Electric Power Technology Co Ltd; Jian Eaglerise Electric Co Ltd; Jian Eaglerise Magnetic Technology Co Ltd
Current assignee: Foshan Yigeer Electronics Co ltd; Eaglerise Electric and Electronic China Co Ltd; Foshan Shunde Eaglerise Electric Power Technology Co Ltd; Jian Eaglerise Electric Co Ltd; Jian Eaglerise Magnetic Technology Co Ltd
Priority date: 2021-11-29
Filing date: 2021-11-29
Publication date: 2022-09-06
Anticipated expiration: 2031-11-29

Abstract

The utility model discloses a lightning protection circuit with low residual voltage and high reliability, which comprises a first filtering module, a second filtering module, a lightning protection module and a rectifying module; the input end of the first filtering module is electrically connected with a mains supply, and the output end of the first filtering module is electrically connected with the input end of the second filtering module; the output end of the second filtering module is electrically connected with the input end of the lightning protection module, the output end of the lightning protection module is electrically connected with the input end of the rectifying module, and the output end of the rectifying module is electrically connected with a load circuit; the application aims at providing a low residual voltage high reliability lightning protection circuit, and piezo-resistor RV1 and two low residual voltage device series connection of discharge tube GD1 increase the withstand voltage of circuit, and shunt resistance R1 and R2 play the voltage-sharing effect, guarantee circuit reliability, shock resistance and prevent mistake switch-on effect.

Description

Low residual voltage high reliability lightning protection circuit

Technical Field

The utility model relates to a protection circuit field especially relates to a low residual voltage high reliability lightning protection circuit.

Background

In a common 220-volt power frequency grid, a common grid fault is that zero line contact is poor or broken, so that the line voltage rises to be close to 380 volts in a short time, and the circuit is easily damaged. In order to protect the circuit, a series branch of a voltage dependent resistor and a discharge tube is connected into the circuit to divide the input voltage. However, such extreme imbalance in the distribution of the operating voltages of the series branches is likely to cause drawbacks. Such as: the direct current breakdown voltage value of the discharge tube needs to be selected to be higher, so that the thickness of the discharge tube is increased, and the price is increased; the capability of tolerating the abnormal fluctuation of the power grid voltage is weak, and the direct-current breakdown voltage value of the discharge tube needs to be greatly improved; the withstand voltage of the serial branch and the residual voltage conflict with each other, the high withstand voltage has high residual voltage, the withstand voltage is lower at low residual voltage, and the high withstand voltage and the low residual voltage cannot be considered; series circuits, as part of more complex combinatorial circuits, also do not work optimally due to non-ideal distribution of operating voltages.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a low residual voltage high reliability lightning protection circuit, piezo-resistor RV1 and two low residual voltage device series connection of discharge tube GD1 increase the withstand voltage of circuit, and parallel resistance R1 and R2 play the voltage-sharing effect, guarantee circuit reliability, impact resistance and prevent mistake switch-on action.

To achieve the purpose, the utility model adopts the following technical proposal: a lightning protection circuit with low residual voltage and high reliability comprises a first filtering module, a second filtering module, a lightning protection module and a rectifying module;

the input end of the first filtering module is electrically connected with a mains supply, and the output end of the first filtering module is electrically connected with the input end of the second filtering module; the output end of the second filtering module is electrically connected with the input end of the lightning protection module, the output end of the lightning protection module is electrically connected with the input end of the rectifying module, and the output end of the rectifying module is electrically connected with a load circuit;

the lightning protection module comprises a piezoresistor RV1, a discharge tube GD1, a resistor R1 and a resistor R2, wherein the piezoresistor RV1 and the discharge tube GD1 are connected in series to form a first branch, the resistor R1 is connected in parallel to two ends of the piezoresistor RV1, and the resistor R2 is connected in parallel to two ends of the discharge tube GD 1; one end of the resistor R1, which is far away from the discharge tube GD1, and one end of the resistor R2, which is far away from the piezoresistor RV1, are electrically connected with the output end of the second filtering module, and two ends of the first branch circuit are electrically connected with the input end of the rectifying module.

Preferably, first filtering module includes electric capacity CX1 and common mode inductance LF1, the both ends of electric capacity CX1 are parallelly connected at common mode inductance LF 1's first pin and fourth pin, common mode inductance LF 1's first pin is connected with the zero line end electricity of commercial power, common mode inductance LF 1's fourth pin is connected with the live wire end electricity of commercial power, common mode inductance LF 1's second pin and third pin are connected with the input electricity of second filtering module.

Preferably, the second filtering module includes electric capacity CX2 and common mode inductance LF2, the both ends of electric capacity CX2 are parallelly connected at common mode inductance LF 2's first pin and fourth pin, common mode inductance LF 2's first pin with common mode inductance LF 1's second pin is connected electrically, common mode inductance LF 2's fourth pin with common mode inductance LF 1's third pin is connected electrically, common mode inductance LF 2's second pin and third pin are connected electrically with the input of lightning protection module.

Preferably, the rectifier module comprises a rectifier bridge DB1, two ac input terminals of the rectifier bridge DB1 are electrically connected to two ends of the first branch, and a positive terminal and a negative terminal of the rectifier bridge DB 1.

Preferably, the power supply further comprises a fuse F1, and the fuse F1 is connected between the input end of the first filtering module and a live wire end of the commercial power.

Preferably, the filter further comprises a piezoresistor RV2, and the piezoresistor RV2 is connected in parallel between the input ends of the first filtering module.

Preferably, the lightning protection module further comprises a thermistor NTC1, one end of the thermistor NTC1 is electrically connected with the second pin of the common-mode inductor LF1, and the other end of the thermistor NTC1 is electrically connected with the lightning protection module.

The utility model discloses a technical scheme's beneficial effect: the voltage-sharing circuit is characterized in that the voltage-sharing resistor is connected with the discharge tube GD1 in series through the voltage dependent resistor RV1, the on-state voltage of the first branch is improved, the voltage-withstanding capability of the circuit is improved, the residual voltage of the circuit is reduced, meanwhile, the resistor R1 is connected in parallel at two ends of the voltage dependent resistor RV1, the resistor R2 is connected in parallel at two ends of the discharge tube GD1, the resistor R1 and the resistor R2 play a role in voltage sharing, the voltage-sharing effect of the voltage-sharing resistor RV1 and the discharge tube GD1 is prevented from bringing risks due to uneven voltage division, the reliability of the circuit is improved, the voltage balance of two devices of the voltage dependent resistor RV1 and the discharge tube GD1 can be guaranteed under high voltage, and the phenomenon that a single device is mistakenly switched on cannot occur.

This application is connected in series through two low residual voltage devices of piezo-resistor RV1 and discharge tube GD1 and is increased the withstand voltage of circuit, and shunt resistance R1 and R2 play the voltage-sharing effect, guarantee circuit reliability, shock resistance and prevent mistake conduction effect.

Drawings

FIG. 1 is a schematic diagram of the circuit connections of an embodiment of the present invention;

fig. 2 is a circuit diagram of an embodiment of the present invention.

Wherein: the lightning protection device comprises a first filtering module 1, a second filtering module 2, a lightning protection module 3 and a rectification module 4.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments with reference to the drawings.

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are exemplary only for explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, "a plurality" means two or more unless otherwise specified.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Referring to fig. 1 and 2, a low residual voltage and high reliability lightning protection circuit includes a first filtering module 1, a second filtering module 2, a lightning protection module 3 and a rectifying module 4;

the input end of the first filtering module 1 is electrically connected with a mains supply, and the output end of the first filtering module 1 is electrically connected with the input end of the second filtering module 2; the output end of the second filtering module 2 is electrically connected with the input end of the lightning protection module 3, the output end of the lightning protection module 3 is electrically connected with the input end of the rectifying module 4, and the output end of the rectifying module 4 is electrically connected with a load circuit;

the lightning protection module 3 comprises a piezoresistor RV1, a discharge tube GD1, a resistor R1 and a resistor R2, wherein the piezoresistor RV1 and the discharge tube GD1 are connected in series to form a first branch, the resistor R1 is connected in parallel to two ends of the piezoresistor RV1, and the resistor R2 is connected in parallel to two ends of the discharge tube GD 1; one end of the resistor R1, which is far away from the discharge tube GD1, and one end of the resistor R2, which is far away from the piezoresistor RV1, are electrically connected with the output end of the second filter module 2, and two ends of the first branch circuit are electrically connected with the input end of the rectifier module 4.

Adopt this kind of structure, connect in series through piezo-resistor RV1 and discharge tube GD1, the turn-on voltage of first branch road has been improved, the withstand voltage ability of circuit has been improved, the circuit residual voltage has been reduced, simultaneously, at the both ends parallel resistance R1 of piezo-resistor RV1, at the both ends parallel resistance R2 of discharge tube GD1, resistance R1 and resistance R2 play the effect of voltage-sharing, prevent that piezo-resistor RV1 and discharge tube GD1 partial pressure are uneven and bring the risk, the reliability of circuit has been improved, under high temperature high pressure, can guarantee that two device voltage of piezo-resistor RV1 and discharge tube GD1 are balanced, the phenomenon that can not have single device misconnection takes place.

In this embodiment, piezo-resistor RV1 is 390V piezo-resistor, and discharge tube GD1 is 200V discharge tube, and the whole withstand voltage of circuit reaches 400Vac, is far above rated input voltage, can work under the power frequency interchange condition of the majority, and the residual voltage of two devices is lower, has reduced the residual voltage of whole circuit in the electric current burst wave.

When the current surge comes, the voltage dependent resistor RV1 is firstly switched on, the resistance value of the voltage dependent resistor RV1 is rapidly reduced, the voltage is applied to the discharge tube GD1, the discharge tube GD1 is switched on to discharge, the residual voltage spike voltage is about 600V, and the plateau voltage is about 400V.

This application is established ties through piezo-resistor RV1 and two low residual voltage devices of discharge tube GD1 and is increased the withstand voltage of circuit, and shunt resistance R1 and R2 play the voltage-sharing effect, guarantee circuit reliability, shock resistance and prevent mistake switch-on effect.

Specifically, first filtering module 1 includes electric capacity CX1 and common mode inductance LF1, the both ends of electric capacity CX1 are parallelly connected at common mode inductance LF 1's first pin and fourth pin, common mode inductance LF 1's first pin is connected with the zero line end electricity of commercial power, common mode inductance LF 1's fourth pin is connected with the live wire end electricity of commercial power, common mode inductance LF 1's second pin and third pin are connected with second filtering module 2's input electricity.

Capacitor CX1 and common mode inductance LF1 constitute EMI filter circuit, can be through the frequency for the alternating current about 50Hz, and the filtering is higher than the high frequency interference clutter more than 50Hz, plays the high frequency pulse interference to the production of commercial power electric wire netting and plays the filtering effect, reduces lightning protection circuit itself simultaneously to external electromagnetic interference.

Preferably, the second filtering module 2 includes a capacitor CX2 and a common mode inductor LF2, the both ends of the capacitor CX2 are connected in parallel at the first pin and the fourth pin of the common mode inductor LF2, the first pin of the common mode inductor LF2 with the second pin of the common mode inductor LF1 is electrically connected, the fourth pin of the common mode inductor LF2 with the third pin of the common mode inductor LF1 is electrically connected, the second pin and the third pin of the common mode inductor LF2 are electrically connected with the input end of the lightning protection module 4.

Capacitor CX2 and common mode inductance LF2 constitute second grade EMI filter circuit, further play the effect of filtering high frequency interference clutter to the circuit, improve the stability of circuit.

Preferably, the rectifier module 4 includes a rectifier bridge DB1, two ac input terminals of the rectifier bridge DB1 are electrically connected to two ends of the first branch, and a positive terminal and a negative terminal of the rectifier bridge DB 1.

The rectifier bridge DB1 converts an ac input into a dc output to provide a stable power supply to the load circuit.

In this application, still include fuse F1, fuse F1 is connected between the input of first filter module 1 and the live wire end of commercial power.

A fuse F1 is provided to protect the current. When the current of the mains supply input is fluctuated to a certain degree, and when the current exceeds a certain value, the fuse F1 generates heat to melt the melt, so that the current is cut off, and the protection effect is achieved.

Specifically, the filter further comprises a piezoresistor RV2, wherein the piezoresistor RV2 is connected in parallel between the input ends of the first filtering module 1.

The voltage dependent resistor RV2 further plays a role of protecting the circuit, and when the circuit bears overvoltage, the voltage dependent resistor RV2 plays a role of voltage clamping, absorbs redundant current and plays a role of protecting the circuit.

Preferably, the lightning protection module further comprises a thermistor NTC1, one end of the thermistor NTC1 is electrically connected with the second pin of the common-mode inductor LF1, and the other end of the thermistor NTC1 is electrically connected with the lightning protection module 3.

In the description of the present specification, references to the description of the terms "embodiment," "example," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The technical principle of the present invention is described above with reference to specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without any inventive effort, which would fall within the scope of the present invention.

Claims

1. A lightning protection circuit with low residual voltage and high reliability is characterized by comprising a first filtering module, a second filtering module, a lightning protection module and a rectifying module;

the lightning protection module comprises a piezoresistor RV1, a discharge tube GD1, a resistor R1 and a resistor R2, wherein the piezoresistor RV1 and the discharge tube GD1 are connected in series to form a first branch, the resistor R1 is connected to two ends of the piezoresistor RV1 in parallel, and the resistor R2 is connected to two ends of the discharge tube GD1 in parallel; one end of the resistor R1, which is far away from the discharge tube GD1, and one end of the resistor R2, which is far away from the piezoresistor RV1, are electrically connected with the output end of the second filtering module, and two ends of the first branch circuit are electrically connected with the input end of the rectifying module.

2. The lightning protection circuit of claim 1, wherein the first filtering module comprises a capacitor CX1 and a common mode inductor LF1, the two ends of the capacitor CX1 are connected in parallel to a first pin and a fourth pin of the common mode inductor LF1, the first pin of the common mode inductor LF1 is electrically connected with a zero line end of a mains supply, the fourth pin of the common mode inductor LF1 is electrically connected with a fire line end of the mains supply, and the second pin and the third pin of the common mode inductor LF1 are electrically connected with an input end of the second filtering module.

3. The lightning protection circuit of claim 2, wherein the second filtering module includes a capacitor CX2 and a common mode inductor LF2, two ends of the capacitor CX2 are connected in parallel to the first pin and the fourth pin of the common mode inductor LF2, the first pin of the common mode inductor LF2 is electrically connected to the second pin of the common mode inductor LF1, the fourth pin of the common mode inductor LF2 is electrically connected to the third pin of the common mode inductor LF1, and the second pin and the third pin of the common mode inductor LF2 are electrically connected to the input terminal of the lightning protection module.

4. The lightning protection circuit with low residual voltage and high reliability according to claim 1, wherein the rectifier module comprises a rectifier bridge DB1, two AC input terminals of the rectifier bridge DB1 are electrically connected with two ends of a first branch, and a positive terminal and a negative terminal of the rectifier bridge DB 1.

5. The lightning protection circuit of claim 1, further comprising a fuse F1, wherein the fuse F1 is connected between the input terminal of the first filtering module and the live line terminal of the commercial power.

6. The lightning protection circuit of claim 1, further comprising a varistor RV2, wherein the varistor RV2 is connected in parallel between the input terminals of the first filtering module.

7. The lightning protection circuit of claim 3, further comprising a thermistor NTC1, wherein one end of the thermistor NTC1 is electrically connected to the second pin of the common-mode inductor LF1, and the other end of the thermistor NTC1 is electrically connected to the lightning protection module.