CN203491882U - Lightning protection circuit of switching power supply - Google Patents

Abstract

A lightning protection circuit of a switching power supply comprises an inlet lightning protection unit and a resonant capacitor lightning protection unit. A metal oxide varistor MOV1 is connected between an inlet power supply L and a power supply N. A metal oxide varistor MOV3 is connected with a metal oxide varistor MOV4 in series, then an air discharge tube RA1 is connected at a midpoint of the metal oxide varistor MOV3, and the other end of the air discharge tube RA1 is connected with an electrical ground FG. Two ends of a resonant capacitor C25 are connected with a metal oxide varistor MOV2 in parallel. Access points of the metal oxide varistor MOV3 and the metal oxide varistor MOV4 are in front of a bridge rectifier circuit. When lightning stroke voltage is transmitted to the power supply from L, N and FG ends of an AC end, a first stage absorption loop composed of the MOV1, the MOV3, the MOV4 and the RA1 absorbs most energy firstly, and partial energy is transmitted to the two ends of the resonant capacitor C25. A second absorption loop composed of the MOV2 eliminates peaks and discharges energy, and thus the loop is protected from being damaged by lightning strokes.

Description

A kind of lightning protection circuit of Switching Power Supply

Technical field

The utility model relates to Switching Power Supply, especially relates to the lightning protection circuit of Switching Power Supply.

Background technology

In prior art, various street lamps all use LED lighting to throw light on, and to reaching the object of saving electric energy, are especially positioned at the both sides of road and the highway in countryside, city, and increasing LED street lamp is used.

Occasion in these fields, the outdoor driving power of high-power LED is widely applied, and because the power supply of LED lighting is all electronic circuit, the Lightning Protection of electronic component is wherein considered with regard to referred more important position.

Utility model content

In order to solve occasion high-power LED outdoor driving power Lightning Protection in field in prior art, the utility model proposes a kind of lightning protection circuit of Switching Power Supply.

The utility model patent is to design for high-power LLC resonant tank SURGE lightning protection, can have suburb to prevent the thunderbolt up to 6～8KV.

The utility model is by adopting following technology to realize:

The lightning protection circuit that manufactures and designs a kind of Switching Power Supply, comprising:

One entrance lightning protection unit;

One resonant capacitance lightning protection unit;

In described entrance lightning protection unit, piezo-resistance MOV1 is connected between entrance power supply L and power supply N, after piezo-resistance MOV3 and piezo-resistance MOV4 serial connection, meets therein an air discharge tube RA1, and another termination of air discharge tube RA1 is FG electrically;

In described resonant capacitance lightning protection unit, the two ends of resonant capacitance C25 also meet a piezo-resistance MOV2.

Described piezo-resistance MOV3 and piezo-resistance MOV4 access point are before bridge rectifier.

When thunderbolt voltage is held L from AC; N, FG holds while reaching power supply, first MOV1; MOV3; MOV4RA1 forms first order absorption circuit, absorbs most of energy, also has portion of energy to reach resonant capacitance C25 two ends; MOV2 forms second level absorption circuit; ream spike, the energy of releasing, thus protection loop exempts from broken by lightning.

Accompanying drawing explanation

Fig. 1 is the electric principle schematic of single led Switching Power Supply in the public constant-current source reference circuit of the many Switching Power Supplies of the utility model.

Embodiment

In order to further illustrate the utility model, now in conjunction with a preferred embodiment of the present utility model, be elaborated, yet described embodiment is only for furnishing an explanation and the use of explaining, can not be used for limiting scope of patent protection of the present utility model.

As shown in Figure 1, the lightning protection circuit of design Switching Power Supply, described circuit comprises:

One entrance lightning protection unit 10;

One resonant capacitance lightning protection unit 13;

In described entrance lightning protection unit 10, piezo-resistance MOV1 is connected between entrance power supply L and power supply N, after piezo-resistance MOV3 and piezo-resistance MOV4 serial connection, meets therein an air discharge tube RA1, and another termination of air discharge tube RA1 is FG electrically;

In described resonant capacitance lightning protection unit 13, the two ends of resonant capacitance C25 also meet a piezo-resistance MOV2.

Described piezo-resistance MOV3 and piezo-resistance MOV4 access point are before bridge rectifier.

PFC control loop 12 in Fig. 1 and LLC resonance control loop 12, be all prior art, at this, is no longer described in detail.

When thunderbolt voltage is held L from AC; N, FG holds while entering power supply, first MOV1; MOV3; MOV4 and RA1 form first order absorption circuit, absorb most of energy, also have portion of energy to reach resonant capacitance C25 two ends; MOV2 forms second level absorption circuit; ream spike, the energy of releasing, thus protection loop exempts from broken by lightning.

The utility model is widely applied on product, since using several years, has had no electronic circuit by broken by lightning.

Do not use the product of the utility model technology to have 10%～20% by the phenomenon of broken by lightning.

Above content is in conjunction with concrete preferred implementation further detailed description of the utility model, can not assert that concrete enforcement of the present utility model is confined to these explanations.For the utility model person of an ordinary skill in the technical field, without departing from the concept of the premise utility, can also make some employing silicon as simple deduction or replace, all should be considered as belonging to protection range of the present utility model.

Claims (2)

1. a lightning protection circuit for Switching Power Supply, is characterized in that, described lightning protection circuit comprises:

One entrance lightning protection unit (10);

One resonant capacitance lightning protection unit (13);

In described entrance lightning protection unit (10), piezo-resistance MOV1 is connected between entrance power supply L and power supply N, after piezo-resistance MOV3 and piezo-resistance MOV4 serial connection, meet therein an air discharge tube RA1, another termination of air discharge tube RA1 is FG electrically;

In described resonant capacitance lightning protection unit (13), the two ends of resonant capacitance C25 also meet a piezo-resistance MOV2.

2. the lightning protection circuit of a kind of Switching Power Supply according to claim 1, is characterized in that:

Described piezo-resistance MOV3 and piezo-resistance MOV4 access point are before bridge rectifier.

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