阅读说明：本技术 一种新型大功率开关电源浪涌电流抑制电路 (Novel high-power switching power supply surge current suppression circuit ) 是由 闫照勇 赵军 张昱 于 2020-11-14 设计创作，主要内容包括：本发明涉及开关电路技术领域,尤其为一种新型大功率开关电源浪涌电流抑制电路,包括EMC电路、整流桥、浪涌电流控制电路、大电容、LLC控制电路、变压器、二次侧整流滤波电路和输出电压反馈电路,整流桥的输入端与EMC电路的输出端连接,浪涌电流控制电路的输入端连接于整流桥的输出端,浪涌电流控制电路的输出端连接有大电容,大电容的输出端连接LLC控制电路和变压器,LLC控制电路的输入端还连接输出电压反馈电路输出端浪涌电流控制电路包括NTC、MOS管Q1、电阻R46和稳压二极管ZD1。本发明可提高电源效率和改善电源温度两个优点,非常实用,可以减少开关电源的输入损耗,还可以改善输入部分元件温度。(The invention relates to the technical field of switch circuits, in particular to a novel surge current suppression circuit of a high-power switch power supply, which comprises an EMC circuit, a rectifier bridge, a surge current control circuit, a large capacitor, an LLC control circuit, a transformer, a secondary side rectifier filter circuit and an output voltage feedback circuit, wherein the input end of the rectifier bridge is connected with the output end of the EMC circuit, the input end of the surge current control circuit is connected with the output end of the rectifier bridge, the output end of the surge current control circuit is connected with the large capacitor, the output end of the large capacitor is connected with the LLC control circuit and the transformer, and the input end of the LLC control circuit is also connected with the surge current control circuit at the output end of the output voltage feedback circuit and comprises an NTC, an MOS tube Q1. The invention can improve the power efficiency and the power temperature, is very practical, can reduce the input loss of the switching power supply, and can improve the element temperature of an input part.)

1. The utility model provides a novel high-power switching power supply surge current suppression circuit, includes EMC circuit, rectifier bridge, surge current control circuit, big electric capacity, LLC control circuit, transformer, secondary side rectification filter circuit and output voltage feedback circuit, the input of rectifier bridge is connected with the output of EMC circuit, surge current control circuit's input is connected in the output of rectifier bridge, surge current control circuit's output is connected with big electric capacity, and LLC control circuit and transformer are connected to the output of big electric capacity, and output voltage feedback circuit output is still connected to LLC control circuit's input, and secondary side rectification filter circuit's output is connected to the output of transformer, surge current control circuit includes NTC, MOS pipe Q1, resistance R46 and zener diode ZD 1.

2. The novel high-power switching power supply surge current suppression circuit according to claim 1, wherein: the internal resistance of the MOS tube Q1 is 0.01-0.05 omega.

3. The novel high-power switching power supply surge current suppression circuit according to claim 1, wherein: the surge current of the large capacitor is 60-100A.

4. The novel high-power switching power supply surge current suppression circuit according to claim 1, wherein: the NTC adopts a negative temperature coefficient thermistor, and the negative temperature coefficient thermistor is a power type thermistor for suppressing surge current.

5. The novel high-power switching power supply surge current suppression circuit according to claim 1, wherein: v of the MOS transistor Q1_DSIs 100V, I_DIs 35A, R_DS(ON)Is 14m omega.

6. The novel high-power switching power supply surge current suppression circuit according to claim 1, wherein: the zener diode ZD1 is used for protecting the MOS transistor Q1.

Technical Field

The invention relates to the technical field of switching circuits, in particular to a novel surge current suppression circuit of a high-power switching power supply.

Background

The input surge current of the switching power supply is always a difficulty which troubles research and development personnel, particularly for a high-power switching power supply, the most effective countermeasure at present is to add a high-power NTC at the input end to solve the problem, but the efficiency of the whole switching power supply is influenced, for example, a NTC with 12A of 5 ohm is added to a 200W switching power supply, when 100Vac is input, if the temperature of an NTC body is 100 ℃, the resistance value of the NTC is about 0.6 ohm, the input current is calculated to be 2A, the consumed power is 1.2W, and the existing problem always influences the efficiency and also influences the temperature of the power supply. The conventional surge suppression circuit works in principle: the AC voltage from the power input end passes through the EMC circuit and the rectifier bridge to charge a large capacitor (at this time, the surge current is large and is generally about 60-100A), the current flows out from the negative electrode after passing through the large capacitor, when the current passes through the NTC1, the surge current is reduced because of the NTC impedance, then the current passes through the rectifier bridge and the EMC circuit to form a loop, the NTC1 can be seen from the upper surge current loop to reduce the surge current by utilizing the self impedance, when the switching power supply normally works, the switching power supply is also a high-power resistor, although the resistance value is reduced along with the temperature rise of the switching power supply, the high-power resistor is also greatly damaged when the switching power supply is applied to the switching power supply of more than 100W.

Disclosure of Invention

The invention aims to provide a novel surge current suppression circuit of a high-power switching power supply, which aims to solve the problem that the input surge current of the switching power supply not only affects the efficiency, but also affects the temperature of the power supply at present in the background technology.

In order to achieve the purpose, the invention provides the following technical scheme:

the utility model provides a novel high-power switching power supply surge current suppression circuit, includes EMC circuit, rectifier bridge, surge current control circuit, big electric capacity, LLC control circuit, transformer, secondary side rectification filter circuit and output voltage feedback circuit, the input of rectifier bridge is connected with the output of EMC circuit, surge current control circuit's input is connected in the output of rectifier bridge, surge current control circuit's output is connected with big electric capacity, and LLC control circuit and transformer are connected to the output of big electric capacity, and output voltage feedback circuit output is still connected to LLC control circuit's input, and secondary side rectification filter circuit's output is connected to the output of transformer, surge current control circuit includes NTC, MOS pipe Q1, resistance R46 and zener diode ZD 1.

Preferably, the internal resistance of the MOS transistor Q1 is 0.01-0.05 omega.

Preferably, the surge current of the large capacitor is 60-100A.

Preferably, the NTC is a negative temperature coefficient thermistor, and the negative temperature coefficient thermistor is a power type thermistor for suppressing a surge current.

Preferably, V of the MOS transistor Q1_DSIs 100V, I_DIs 35A, R_DS(ON)Is 14m omega.

Preferably, the zener diode ZD1 is used to protect the MOS transistor Q1.

Compared with the prior art, the invention has the beneficial effects that:

1. this novel high-power switching power supply surge current suppression circuit can improve power efficiency and improve two advantages of power supply temperature, and is very practical, can reduce switching power supply's input loss, can also improve input part component temperature.

2. When the novel high-power switching power supply surge current suppression circuit works, AC voltage incoming from a power supply input end passes through an EMC circuit and a rectifier bridge to charge a large capacitor (at the moment, the surge current is very large and is generally about 60-100A), the current flows out from a negative electrode after passing through the large capacitor, when the current passes through NTC1, the surge current is reduced due to NTC impedance, then the surge current passes through the rectifier bridge and the EMC circuit to form a loop, when a switching power supply control circuit is started, voltage is generated on an auxiliary winding of a transformer, VCC voltage is output after being rectified by a diode D1, the VCC voltage drives an MOS tube Q1 through R46, MOS adopts low-voltage low internal resistance, adopts the voltage of less than 0.05 omega, a voltage stabilizing diode 1 is used for preventing Q1 from being damaged when VCC is too high, after MOS is conducted, the thermistor is equivalent to short-circuit NTC1, at the moment, the resistance of NTC1 is connected with the conduction internal resistance of Q1 in, the NTC power consumption is calculated by adopting a 200W switching power supply, and the input current 2A is used for calculation, specifically: 2A × 0.05 Ω ═ 0.1W; 1.1W is reduced compared with the conventional 1.2W, and the NTC body does not dissipate heat and improves the power supply temperature.

Drawings

FIG. 1 is an overall circuit schematic of the present invention;

FIG. 2 is a schematic diagram of an inrush current control circuit according to the present invention;

FIG. 3 is a schematic diagram of a portion of a circuit according to the present invention;

FIG. 4 is a second partial circuit diagram of the present invention;

fig. 5 is a schematic flow chart of the working principle of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the equipment or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Referring to fig. 1-5, the present invention provides the following technical solutions:

the utility model provides a novel high-power switching power supply surge current suppression circuit, including the EMC circuit, the rectifier bridge, surge current control circuit, big electric capacity, LLC control circuit, the transformer, secondary side rectification filter circuit and output voltage feedback circuit, the input of rectifier bridge is connected with the output of EMC circuit, surge current control circuit's input is connected in the output of rectifier bridge, surge current control circuit's output is connected with big electric capacity, LLC control circuit and transformer are connected to big electric capacity's output, output voltage feedback circuit output is still connected to LLC control circuit's input, secondary side rectification filter circuit's output is connected to the output of transformer, surge current control circuit includes the NTC, MOS pipe Q1, resistance R46 and zener diode ZD 1.

Specifically, the internal resistance of the MOS transistor Q1 in this embodiment is 0.05 Ω, and the surge current of the large capacitor is 60 to 100A.

It should be noted that the NTC employs a negative temperature coefficient thermistor, which is a power type thermistor for suppressing a surge current.

Further, V of MOS transistor Q1_DSIs 100V, I_DIs 35A, R_DS(ON)At 14m Ω, the zener diode ZD1 is used to protect the MOS transistor Q1.

The working principle of the novel high-power switching power supply surge current suppression circuit is as follows:

the AC voltage from the power input end passes through the EMC circuit and the rectifier bridge to charge a large capacitor (at this time, the surge current is very large and is generally about 60-100A), the current flows out from the negative electrode after passing through the large capacitor, when the current passes through the NTC1, the surge current is reduced because of the NTC impedance, then the surge current passes through the rectifier bridge and the EMC circuit to form a loop, when the switching power supply control circuit is started, the voltage is generated on the auxiliary winding of the transformer, the VCC voltage is output after being rectified by a diode D1, the VCC voltage drives a MOS tube Q1 through R46, the MOS adopts a low voltage with low internal resistance of less than 0.05 omega, a voltage stabilizing diode ZD1 is used for preventing the Q1 from being damaged when the VCC is too high, after the MOS is conducted, the thermistor is equivalent to short circuit NTC1, and the resistance is the conduction of the NTC1 in parallel connection with the Q1 and.

In this embodiment, a 200W switching power supply is used to calculate the NTC power consumption, and the input current 2A is used to calculate, specifically:

2A*0.05Ω＝0.1W；

reduce 1.1W than traditional 1.2W, NTC body does not have the heat to come out yet moreover, has improved the power temperature simultaneously, can prove from above, this novel switching power supply surge current suppression circuit has two advantages of improving power efficiency and improving the power temperature, and is very practical, can reduce switching power supply's input loss, can also improve input part component temperature.

The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and the preferred embodiments of the present invention are described in the above embodiments and the description, and are not intended to limit the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.