WO2015051688A1 - 开关电源输入电压保护电路 - Google Patents

开关电源输入电压保护电路 Download PDF

Info

Publication number
WO2015051688A1
WO2015051688A1 PCT/CN2014/086319 CN2014086319W WO2015051688A1 WO 2015051688 A1 WO2015051688 A1 WO 2015051688A1 CN 2014086319 W CN2014086319 W CN 2014086319W WO 2015051688 A1 WO2015051688 A1 WO 2015051688A1
Authority
WO
WIPO (PCT)
Prior art keywords
resistor
power supply
voltage
switching power
circuit
Prior art date
Application number
PCT/CN2014/086319
Other languages
English (en)
French (fr)
Inventor
景铁龙
程良意
Original Assignee
珠海格力电器股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 珠海格力电器股份有限公司 filed Critical 珠海格力电器股份有限公司
Publication of WO2015051688A1 publication Critical patent/WO2015051688A1/zh

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/22—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices
    • H02H7/222—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions for distribution gear, e.g. bus-bar systems; for switching devices for switches
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/04—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage
    • H02H9/042—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage comprising means to limit the absorbed power or indicate damaged over-voltage protection device

Definitions

  • the present invention relates to the field of circuits, and in particular to a switching power supply input voltage protection circuit.
  • the overvoltage protection function of the switching power supply bus there are two methods for implementing the overvoltage protection function of the switching power supply bus.
  • One is that the chip itself of the switching power supply has its own overvoltage protection function, but many chips do not have this protection function, so it is necessary to use an external protection circuit.
  • the other is to realize the overvoltage protection function of the switching power supply bus through the external protection circuit.
  • the protection circuit is used to detect the bus voltage. When the detected bus voltage exceeds a certain value, the protection circuit outputs a trigger power supply chip.
  • the signal of other protection functions prevents the working device of the switching power supply from being damaged when the input voltage is too high, because the protection circuit starts the other protection functions of the switching power supply chip, the premise is that the input voltage is excessive Under the condition of pressure, it can be realized when the MOS tube has a switching action in the switching power supply chip. If the input voltage is overvoltage, the MOS tube in the switching power supply cannot be completely avoided, especially when it is commercial. Air conditioning unidirectional switching power supply is connected to three-phase or single-phase power When the pressure is too high, the MOS switch operation once the tube is likely to be blown up, and is not able to give protection to the input of the undervoltage.
  • a switching power supply input voltage protection circuit comprises a switching power supply input end, a first voltage dividing circuit, a second voltage dividing circuit, a reference voltage stabilizing source and a switch control circuit;
  • the first voltage dividing circuit is connected in parallel with the second voltage dividing circuit, and the input end of the first voltage dividing circuit and the input end of the second voltage dividing circuit are respectively connected to the input end of the switching power supply;
  • a first output end of the first voltage dividing circuit is connected to a cathode of the reference voltage stabilizing source, and a second output end of the first voltage dividing circuit is connected to an anode of the reference voltage stabilizing source and grounded;
  • a first output end of the second voltage dividing circuit is connected to a sampling end of the reference voltage stabilizing source, and a second output end of the second voltage dividing circuit is grounded;
  • a first input end of the switch control circuit is connected to a cathode of the reference voltage stabilizing source, and an output end of the switch control circuit is electrically connected to a power supply pin end of the main control chip of the switching power supply, the switch control circuit
  • the second input is grounded;
  • the first voltage dividing circuit is used for the cathode voltage division of the reference voltage stabilizing source
  • the second voltage dividing circuit is used for dividing the sampling end of the reference voltage stabilizing source
  • the switch control circuit is used for controlling the The switching power supply is turned on and off, the sampling voltage of the reference voltage stabilizing source affects the working state of the switch control circuit, and the working state of the switch control circuit affects the switching power supply.
  • the first voltage dividing circuit comprises a first resistor, a second resistor and a third resistor, wherein the first resistor, the second resistor and the third resistor are connected in series, and are connected in series at the input end of the switching power supply and the ground.
  • the second resistor is connected in series between the first resistor and the third resistor;
  • a common end of the second resistor and the third resistor serves as a first output end of the first voltage dividing circuit, and a ground end of the third resistor serves as a second output end of the first voltage dividing circuit.
  • the second voltage dividing circuit comprises a fourth resistor, a fifth resistor and a sixth resistor, wherein the fourth resistor, the fifth resistor and the sixth resistor are connected in series, and are connected in series at the input end and the ground end of the switching power supply.
  • the fifth resistor is connected in series between the fourth resistor and the sixth resistor;
  • the ground end of the sixth resistor serves as a second output end of the second voltage dividing circuit.
  • the switch control circuit includes a seventh resistor, an eighth resistor, a diode, and a triode;
  • a base of the triode is sequentially connected in series with the seventh resistor and the diode, and then connected to a cathode of the reference voltage stabilizing source, and a common end of the diode corresponding to a cathode of the reference voltage stabilizing source serves as the switch control circuit First input;
  • a collector of the triode is connected in series with the eighth resistor and grounded, and a ground end of the eighth resistor serves as a second input end of the switch control circuit;
  • the emitter of the triode is connected to a power supply pin end of the main control chip of the switching power supply, and an emitter of the triode serves as an output end of the switch control circuit.
  • the triode is a PNP triode.
  • the reference voltage regulator is of the type TL431.
  • the invention provides a switching power supply input voltage protection circuit, a first voltage dividing circuit divides a cathode of a reference voltage stabilizing source, and a second voltage dividing circuit divides a sampling end of a reference voltage stabilizing source to make a sampling voltage of a reference voltage stabilizing source Affecting the working state of the switch control circuit, the working state of the switch control circuit affects the on/off of the switching power supply, and can play a protection function when the input voltage of the switching power supply is too high or too low, which effectively solves the input overvoltage and undervoltage The problem that the MOS tube is damaged in the switching power supply.
  • FIG. 1 is a schematic diagram of an embodiment of a switching power supply input voltage protection circuit of the present invention.
  • an embodiment of a switching power supply input voltage protection circuit of the present invention includes a switching power supply input terminal V DC , a first voltage dividing circuit 100 , a second voltage dividing circuit 200 , a reference voltage stabilizing source U1 , and a switch control circuit 300 .
  • a voltage dividing circuit 100 is connected in parallel with the second voltage dividing circuit 200.
  • the input terminal IN110 of the first voltage dividing circuit and the input terminal IN210 of the second voltage dividing circuit are respectively connected to the switching power supply input terminal V DC , and the first voltage dividing circuit is The first output terminal OUT120 is connected to the cathode CU1 of the reference voltage stabilizing source, the second output terminal OUT130 of the first voltage dividing circuit is connected to the anode AU1 of the reference voltage stabilizing source and grounded, and the first output terminal IN220 of the second voltage dividing circuit is connected to the reference stable
  • the sampling terminal RU1 of the voltage source, the second output terminal OUT230 of the second voltage dividing circuit is grounded, the first input terminal IN310 of the switching control circuit 300 is connected to the cathode CU1 of the reference voltage stabilizing source U1, and the output terminal OUT330 of the switching control circuit 300 is
  • the main control chip of the switching power supply is electrically connected to the pin terminal V CC , and the second input terminal IN320 of the switch control circuit 300 is grounded.
  • the reference voltage regulator source U1 is preferably a reference voltage regulator source of the TL431, the first voltage divider circuit 100 is used for dividing the cathode CU1 of the reference voltage regulator source, and the second voltage divider circuit 200 is used for the sampling terminal RU1 of the reference voltage regulator source.
  • the voltage, switch control circuit 300 is used to control the on/off of the switching power supply, and the sampling voltage of the reference voltage regulator source U1 affects the working state of the switch control circuit, and the switch The working state of the control circuit 300 affects the on/off of the switching power supply, effectively avoiding the phenomenon that the switching power supply device is damaged under the condition of input overvoltage and input undervoltage, the circuit reaction speed is fast, and the instantaneous protection can be realized. After the input voltage returns to normal, normal operation starts and there is no restart.
  • the first voltage dividing circuit 100 includes a first resistor R1, a second resistor R2, and a third resistor R3.
  • the first resistor R1, the second resistor R2, and the third resistor R3 are connected in series, in series.
  • the second resistor R2 is connected in series between the first resistor R1 and the third resistor R3; the corresponding common end of the second resistor R2 and the third resistor R3 is used as the first voltage divider
  • the first output terminal OUT120 of the circuit and the ground terminal of the third resistor R3 serve as the second output terminal OUT130 of the first voltage dividing circuit.
  • the reference voltage regulator U1 can have an operating current of at least about 1 mA, and when the input voltage of the switching power supply is low, the voltage of the third resistor R3 is also low, so that the voltage of the base B of the transistor U2 is low. Transistor U2 is turned on and starts to protect.
  • the second voltage dividing circuit 200 includes a fourth resistor R4, a fifth resistor R5, and a sixth resistor R6.
  • the fourth resistor R4, the fifth resistor R5, and the sixth resistor R6 are connected in series, in series.
  • the fifth resistor R5 is connected in series between the fourth resistor R4 and the sixth resistor R6; the corresponding common terminal of the fifth resistor R5 and the sixth resistor R6 is used as the second voltage divider
  • the first output terminal OUT220 of the circuit; the ground terminal of the sixth resistor R6 serves as the second output terminal OUT230 of the second voltage dividing circuit.
  • the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are used to divide the sampling terminal RU1 of the reference voltage stabilizing source U1, and the resistance values of the fourth resistor R4, the fifth resistor R5 and the sixth resistor R6 are reasonably set, so that When the input voltage of the switching power supply is the set maximum protection voltage, that is, the threshold voltage value, the voltage of the sixth resistor R6 is equal to 2.5V, that is, the voltage of the sampling terminal RU1 of the reference voltage regulator source U1 is 2.5V.
  • the switch control circuit 300 includes a seventh resistor R7, an eighth resistor R8, a diode D1, and a transistor U2.
  • the base B of the transistor U2 is sequentially connected in series with the seventh resistor R7 and the diode D1.
  • the cathode CU1 of the voltage regulator source U1, the common terminal of the diode D1 corresponding to the cathode CU1 of the reference voltage regulator source is the first input terminal IN310 of the switch control circuit 300; wherein the transistor U2 is a PNP transistor.
  • the collector C of the transistor grounded with an eighth resistor R8, an eighth resistor R8 to ground the second input terminal of the switching control circuit 300 IN320; master chip supply pin terminal E connected to the emitter of transistor switching power supply V CC
  • the emitter E of the transistor acts as the output terminal OUT330 of the switch control circuit.
  • the input voltage V DC is within the normal range, the input voltage V DC is divided by the second voltage dividing circuit 200, so that the voltage V RU1 of the reference voltage source sampling terminal RU1 is less than 2.5V, due to the reference voltage regulator source TL431 The reference voltage is 2.5V. Therefore, the reference regulator source TL431 is in the off state.
  • the cathode voltage CU1 of the reference regulator source TL431 is the voltage value V R3 of the third resistor R3, and the voltage of the cathode CU1 of the reference regulator source TL431.
  • the PNP type transistor U2 is in an off state, and the switching power supply input voltage protection circuit is in an inoperative state, and does not have any influence on the switching power supply.
  • the input voltage V DC of the switching power supply is lower than the threshold voltage
  • the input voltage V DC is divided by the second voltage dividing circuit 200, so that the voltage V RU1 of the sampling terminal RU1 of the reference voltage regulator is less than 2.5V, and the reference is stable.
  • the voltage source TL431 is in an off state, but since the input voltage is lower than the threshold voltage value, the voltage divided by the third resistor R3 is correspondingly low, causing the diode D1 to be turned on, thereby making the base B and the emitter of the PNP type transistor U2
  • the voltage V EB between E is greater than 0.7V and is in a conducting state; after the PNP transistor U2 is turned on, the current of the switching power supply chip terminal V CC connected to the emitter E thereof flows through the PNP transistor U2 to the ground terminal. GND, so that the voltage V CC of the power supply pin of the switching power supply chip is pulled low.
  • the switching power supply stops working, reducing the switching power supply loss, and avoiding the protection process caused by the input undervoltage.
  • the switching power supply device is damaged, and after the input voltage V DC returns to the normal range, the switching power supply starts to work normally.
  • the input voltage V DC of the switching power supply is higher than the threshold voltage
  • the input voltage V DC is divided by the second voltage dividing circuit, so that the voltage V RU1 of the sampling terminal RU1 of the reference voltage regulator is greater than 2.5V
  • the reference voltage regulator When the source TL431 is in the on state, the level of the cathode CU1 of the reference regulator source TL431 is instantaneously pulled to a low potential, and the diode D1 is turned on, thereby affecting that the base B of the PNP transistor U2 is also pulled to a low potential, and the PNP type transistor is emitted.
  • the pole E is electrically connected to the power supply pin terminal V CC of the switching power supply chip, and the PNP type transistor U2 is turned on, so that the level V CC of the power supply pin terminal of the switching power supply chip is immediately pulled low, the switching power supply stops working, and the MOS transistor no longer has The switching action, until the input voltage returns to the normal range, the switching power supply will start to work, avoiding the MOS tube being damaged when the input overvoltage occurs.
  • the switching power supply input voltage protection circuit controls the switching state of the reference voltage stabilizing source through the first voltage dividing circuit and the second voltage dividing circuit, thereby affecting the working state of the switch control circuit, and the switch control circuit controls the switching power supply through its own working state.
  • the working state effectively avoids the phenomenon that the switching power supply device is damaged under the condition of input overvoltage and input undervoltage, the circuit reacts fast, realizes instantaneous protection, and the normal operation after the input voltage returns to normal, and There is no restart.

Landscapes

  • Dc-Dc Converters (AREA)
  • Protection Of Static Devices (AREA)
  • Emergency Protection Circuit Devices (AREA)

Abstract

一种开关电源输入电压保护电路，包括开关电源输入端、第一分压电路、第二分压电路、基准稳压源和开关控制电路，第一分压电路用于基准稳压源的阴极分压，第二分压电路用于基准稳压源的采样端分压，开关控制电路用于控制开关电源的通断，基准稳压源的采样电压影响开关控制电路的工作状态，开关控制电路的工作状态影响开关电源的通断。该开关电源输入电压保护电路有效解决了开关电源的输入电压过压和欠压时，开关电源中MOS管损坏的问题。

Description

开关电源输入电压保护电路
相关申请
本专利申请要求2013年10月9日申请的，申请号为201310466813.5，名称为“开关电源输入电压保护电路”的中国专利申请的优先权，在此将其全文引入作为参考。
技术领域
本发明涉及电路领域，特别是涉及一种开关电源输入电压保护电路。
背景技术
目前，实现开关电源母线过压保护功能的方法分为两种，一种是靠开关电源的芯片本身自带过压保护功能来实现，但是很多芯片没有该保护功能，因此需要通过外接保护电路来实现；另一种是通过外接保护电路实现开关电源母线过压保护功能，通常是采用该保护电路检测母线电压，当检测到的母线电压超过某值后，该保护电路输出一个能够触发开关电源芯片的其他保护功能的信号，从而实现开关电源母线过压保护功能，防止输入电压过高时，损坏开关电源的工作器件，由于该保护电路启动开关电源芯片的其他保护功能的前提是在输入电压过压的情况下才能实现，也就是在开关电源芯片中MOS管已经有开关动作的时候才会出现保护，如果输入电压过压就无法完全避免开关电源中MOS管被损坏的现象，尤其是当商用空调单向开关电源在接入三相电或单相电电压过高时，MOS管一旦有开关动作就有可能被炸毁，并且对于输入电压欠压的情况也不能够给予保护。
发明内容
基于此，有必要针对在输入电压在过压和欠压时，开关电源中MOS管被损坏的问题，提供一种开关电源输入电压保护电路。
为实现本发明目的，采用如下技术方案：
一种开关电源输入电压保护电路，包括开关电源输入端、第一分压电路、第二分压电路、基准稳压源和开关控制电路；
所述第一分压电路与第二分压电路并联连接，所述第一分压电路的输入端和所述第二分压电路的输入端分别与所述开关电源输入端连接；
所述第一分压电路的第一输出端连接所述基准稳压源的阴极，所述第一分压电路的第二输出端连接所述基准稳压源的阳极并接地；
所述第二分压电路的第一输出端连接所述基准稳压源的采样端，所述第二分压电路的第二输出端接地；
所述开关控制电路的第一输入端与所述基准稳压源的阴极连接，所述开关控制电路的输出端与所述开关电源的主控芯片供电引脚端电连接，所述开关控制电路的第二输入端接地；
所述第一分压电路用于所述基准稳压源的阴极分压，所述第二分压电路用于所述基准稳压源的采样端分压，所述开关控制电路用于控制所述开关电源的通断，所述基准稳压源的采样电压影响所述开关控制电路的工作状态，所述开关控制电路的工作状态影响所述开关电源的通断。
较优地，所述第一分压电路包括第一电阻、第二电阻和第三电阻，所述第一电阻、第二电阻和第三电阻串联，串联在所述开关电源输入端与接地端之间，所述第二电阻串联于所述第一电阻和所述第三电阻之间；
所述第二电阻和第三电阻相应的公共端作为所述第一分压电路的第一输出端，所述第三电阻的接地端作为所述第一分压电路的第二输出端。
较优地，所述第二分压电路包括第四电阻、第五电阻和第六电阻，所述第四电阻、第五电阻和第六电阻串联，串联在所述开关电源输入端与接地端之间，所述第五电阻串联于所述第四电阻和所述第六电阻之间；
所述第五电阻和第六电阻相应的公共端作为所述第二分压电路的第一输出端；
所述第六电阻的接地端作为所述第二分压电路的第二输出端。
较优地，所述开关控制电路包括第七电阻、第八电阻、二极管和三极管；
所述三极管的基极依次串联所述第七电阻和所述二极管后连接所述基准稳压源的阴极，所述二极管与所述基准稳压源的阴极相应的公共端作为所述开关控制电路的第一输入端；
所述三极管的集电极串联所述第八电阻后接地，所述第八电阻的接地端作为所述开关控制电路的第二输入端；
所述三极管的发射极与所述开关电源的主控芯片供电引脚端连接，所述三极管的发射极作为所述开关控制电路的输出端。
较优地，所述三极管为PNP三极管。
较优地，所述基准稳压源的型号为TL431。
本发明的有益效果是：
本发明提供的开关电源输入电压保护电路，第一分压电路对基准稳压源的阴极分压，第二分压电路对基准稳压源的采样端分压，使得基准稳压源的采样电压影响开关控制电路的工作状态，开关控制电路的工作状态影响开关电源的通断，在开关电源输入电压过高或过低时都能起到保护功能，其有效解决了输入过压和欠压时，开关电源中MOS管被损坏的问题。
附图说明
图1为本发明的开关电源输入电压保护电路一实施例的示意图。
具体实施方式
为了使本发明的技术方案更加清楚，以下结合附图，对本发明的开关电源输入电压保护电路作进一步详细的说明。应当理解，此处所描述的具体实施例仅用以解释本发明，并不用于限定本发明。
参见图1，本发明的开关电源输入电压保护电路一实施例包括开关电源输入端VDC、第一分压电路100、第二分压电路200、基准稳压源U1和开关控制电路300，第一分压电路100与第二分压电路200并联连接，第一分压电路的输入端IN110和第二分压电路的输入端IN210分别与开关电源输入端VDC连接，第一分压电路的第一输出端OUT120连接基准稳压源的阴极CU1，第一分压电路的第二输出端OUT130连接基准稳压源的阳极AU1并接地，第二分压电路的第一输出端IN220连接基准稳压源的采样端RU1，第二分压电路的第二输出端OUT230接地，开关控制电路300的第一输入端IN310与基准稳压源U1的阴极CU1连接，开关控制电路300的输出端OUT330与开关电源的主控芯片供电引脚端VCC电连接，开关控制电路300的第二输入端IN320接地。
基准稳压源U1优选型号为TL431的基准稳压源，第一分压电路100用于基准稳压源的阴极CU1分压，第二分压电路200用于基准稳压源的采样端RU1分压，开关控制电路300用于控制开关电源的通断，基准稳压源U1的采样电压影响开关控制电路的工作状态，开关 控制电路300的工作状态影响开关电源的通断，有效地避免了在输入过压和输入欠压的情况下，开关电源器件被损坏的现象，电路反应速度快，可以做到瞬时保护，开关电源输入电压恢复正常后随即开始正常工作，且不会出现重启动现象。
较优地，作为一种可实施方式，第一分压电路100包括第一电阻R1、第二电阻R2和第三电阻R3，第一电阻R1、第二电阻R2和第三电阻R3串联，串联在开关电源输入端VDC与接地端GND之间，第二电阻R2串联于第一电阻R1和第三电阻R3之间；第二电阻R2和第三电阻R3相应的公共端作为第一分压电路的第一输出端OUT120，第三电阻R3的接地端作为第一分压电路的第二输出端OUT130。
通过合理设置第一电阻R1、第二电阻R2和第三电阻R3的阻值，保证第一电阻R1、第二电阻R2和第三电阻R3从开关电源输入端分得的电压使得在正常工作电压范围内，基准稳压源U1能够至少有大概1mA左右的工作电流，并且当开关电源输入电压较低时，第三电阻R3分得的电压也低，从而使得三极管U2基极B电压较低触发三极管U2导通，启动保护。
较优地，作为一种可实施方式，第二分压电路200包括第四电阻R4、第五电阻R5和第六电阻R6，第四电阻R4、第五电阻R5和第六电阻R6串联，串联在开关电源输入端VDC与接地端GND之间，第五电阻R5串联于第四电阻R4和第六电阻R6之间；第五电阻R5和第六电阻R6相应的公共端作为第二分压电路的第一输出端OUT220；第六电阻R6的接地端作为第二分压电路的第二输出端OUT230。第四电阻R4、第五电阻R5和第六电阻R6用来给基准稳压源U1的采样端RU1分压，合理设置第四电阻R4、第五电阻R5和第六电阻R6的阻值，使得在开关电源输入电压为所设定的最高保护电压即临界电压值时，第六电阻R6分得的电压等于2.5V，即基准稳压源U1的采样端RU1的电压为2.5V。
较优地，作为一种可实施方式，开关控制电路300包括第七电阻R7、第八电阻R8、二极管D1和三极管U2；三极管U2的基极B依次串联第七电阻R7和二极管D1后连接基准稳压源U1的阴极CU1，二极管D1与基准稳压源的阴极CU1相应的公共端作为开关控制电路300的第一输入端IN310；其中，三极管U2为PNP三极管。
三极管的集电极C串联第八电阻R8后接地，第八电阻R8的接地端作为开关控制电路300的第二输入端IN320；三极管的发射极E连接开关电源的主控芯片供电引脚端VCC，三极管的发射极E作为开关控制电路的输出端OUT330。二极管D1用于防止开关电源输入电压高但还未达到保护的临界电压值时，第三电阻R3分压较高导致三极管的基极与发射极之 间的电压VBE过高而损坏器件。
当输入电压VDC在正常范围内时，经第二分压电路200对输入电压VDC进行分压，使得基准稳压源采样端RU1的电压VRU1小于2.5V，由于基准稳压源TL431的基准电压为2.5V，因此，基准稳压源TL431处于截止状态，基准稳压源TL431的阴极CU1电压VCU1为第三电阻R3分得的电压值VR3，基准稳压源TL431阴极CU1的电压为高电平，PNP型三极管U2处于截止状态，该开关电源输入电压保护电路处于不工作状态，对开关电源不产生任何影响。
当开关电源的输入电压VDC低于临界电压值时，经第二分压电路200对输入电压VDC进行分压，同样使得基准稳压源采样端RU1的电压VRU1小于2.5V，基准稳压源TL431处于截止状态，但是由于输入电压低于临界电压值，所以第三电阻R3分得的电压相应也很低，导致二极管D1导通，从而使得PNP型三极管U2的基极B与发射极E之间的电压VEB大于0.7V而处于导通状态；PNP型三极管U2导通后，与其发射极E相连接的开关电源芯片供电引脚端VCC的电流通过PNP型三极管U2流向接地端GND，从而使得开关电源芯片供电引脚端的电压VCC被拉低，VCC被拉低后，开关电源停止工作，减小了开关电源损耗，避免了在输入欠压时，保护过程中引起的开关电源器件损坏的现象，并且在输入电压VDC恢复正常范围后，开关电源开始正常工作。
当开关电源的输入电压VDC高于临界电压值时，经第二分压电路对输入电压VDC进行分压，同样使得基准稳压源采样端RU1的电压VRU1大于2.5V，基准稳压源TL431处于导通状态，基准稳压源TL431阴极CU1电平瞬时被拉到低电位，二极管D1导通，从而影响PNP型三极管U2的基极B同时也被拉到低电位，PNP型三极管发射极E与开关电源芯片供电引脚端VCC电连接，PNP型三极管U2导通，从而使得开关电源芯片供电引脚端的电平VCC随即被拉低，开关电源停止工作，MOS管不再有开关动作，直到输入电压恢复正常范围，开关电源才会开始工作，避免了输入过压时MOS管被损坏的现象。
本发明提供的开关电源输入电压保护电路通过第一分压电路和第二分压电路控制基准稳压源的开关状态，进而影响开关控制电路的工作状态，开关控制电路通过自身工作状态控制开关电源的工作状态，其有效地避免了在输入过压和输入欠压的情况下，开关电源器件被损坏的现象，电路反应速度快，做到瞬时保护，输入电压恢复正常后随即开始正常工作，且不会出现重启动现象。
以上所述实施例仅表达了本发明的几种实施方式，其描述较为具体和详细，但并不能 因此而理解为对本发明专利范围的限制。应当指出的是，对于本领域的普通技术人员来说，在不脱离本发明构思的前提下，还可以做出若干变形和改进，这些都属于本发明的保护范围。因此，本发明专利的保护范围应以所附权利要求为准。

Claims (6)

  1. 一种开关电源输入电压保护电路，其特征在于：
    包括开关电源输入端、第一分压电路、第二分压电路、基准稳压源和开关控制电路；
    所述第一分压电路与第二分压电路并联连接，所述第一分压电路的输入端和所述第二分压电路的输入端分别与所述开关电源输入端连接；
    所述第一分压电路的第一输出端连接所述基准稳压源的阴极，所述第一分压电路的第二输出端连接所述基准稳压源的阳极并接地；
    所述第二分压电路的第一输出端连接所述基准稳压源的采样端，所述第二分压电路的第二输出端接地；
    所述开关控制电路的第一输入端与所述基准稳压源的阴极连接，所述开关控制电路的输出端与所述开关电源的主控芯片供电引脚端电连接，所述开关控制电路的第二输入端接地；
    所述第一分压电路用于所述基准稳压源的阴极分压，所述第二分压电路用于所述基准稳压源的采样端分压，所述开关控制电路用于控制所述开关电源的通断，所述基准稳压源的采样电压影响所述开关控制电路的工作状态，所述开关控制电路的工作状态影响所述开关电源的通断。
  2. 根据权利要求1所述的开关电源输入电压保护电路，其特征在于：
    所述第一分压电路包括第一电阻、第二电阻和第三电阻，所述第一电阻、第二电阻和第三电阻串联，串联在所述开关电源输入端与接地端之间，所述第二电阻串联于所述第一电阻和所述第三电阻之间；
    所述第二电阻和第三电阻相应的公共端作为所述第一分压电路的第一输出端，所述第三电阻的接地端作为所述第一分压电路的第二输出端。
  3. 根据权利要求1所述的开关电源输入电压保护电路，其特征在于：
    所述第二分压电路包括第四电阻、第五电阻和第六电阻，所述第四电阻、第五电阻和第六电阻串联，串联在所述开关电源输入端与接地端之间，所述第五电阻串联于所述第四电阻和所述第六电阻之间；
    所述第五电阻和第六电阻相应的公共端作为所述第二分压电路的第一输出端；
    所述第六电阻的接地端作为所述第二分压电路的第二输出端。
  4. 根据权利要求1所述的开关电源输入电压保护电路，其特征在于：
    所述开关控制电路包括第七电阻、第八电阻、二极管和三极管；
    所述三极管的基极依次串联所述第七电阻和所述二极管后连接所述基准稳压源的阴极，所述二极管与所述基准稳压源的阴极相应的公共端作为所述开关控制电路的第一输入端；
    所述三极管的集电极串联所述第八电阻后接地，所述第八电阻的接地端作为所述开关控制电路的第二输入端；
    所述三极管的发射极与所述开关电源的主控芯片供电引脚端连接，所述三极管的发射极作为所述开关控制电路的输出端。
  5. 根据权利要求4所述的开关电源输入电压保护电路，其特征在于：
    所述三极管为PNP三极管。
  6. 根据权利要求1至5任一项所述的开关电源输入电压保护电路，其特征在于：
    所述基准稳压源的型号为TL431。
PCT/CN2014/086319 2013-10-09 2014-09-11 开关电源输入电压保护电路 WO2015051688A1 (zh)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201310466813.5A CN104577993B (zh) 2013-10-09 2013-10-09 开关电源输入电压保护电路
CN201310466813.5 2013-10-09

Publications (1)

Publication Number Publication Date
WO2015051688A1 true WO2015051688A1 (zh) 2015-04-16

Family

ID=52812512

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2014/086319 WO2015051688A1 (zh) 2013-10-09 2014-09-11 开关电源输入电压保护电路

Country Status (2)

Country Link
CN (1) CN104577993B (zh)
WO (1) WO2015051688A1 (zh)

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107124022A (zh) * 2017-06-14 2017-09-01 中能易电新能源技术有限公司 蓄电池充电保护电路
CN108110835A (zh) * 2017-12-27 2018-06-01 苏州易美新思新能源科技有限公司 一种用于高压电池系统的低功耗控制电路
CN108919728A (zh) * 2018-08-23 2018-11-30 深圳和而泰智能控制股份有限公司 一种控制电路
CN109450031A (zh) * 2018-12-03 2019-03-08 京信通信系统（中国）有限公司 一种电池过放电保护电路
CN109546847A (zh) * 2019-01-16 2019-03-29 合肥惠科金扬科技有限公司 开关电源的同步关断电路、驱动电路及同步关断方法
CN109672255A (zh) * 2019-02-25 2019-04-23 威胜信息技术股份有限公司 后备电容充放电电路、充放电方法及其故障指示器
CN109757020A (zh) * 2019-03-12 2019-05-14 江苏北方湖光光电有限公司 一种基于微光保护的控制电路
CN109888738A (zh) * 2019-01-25 2019-06-14 惠州三华工业有限公司 自锁式输出过压保护电路及电压输出系统
CN110445100A (zh) * 2019-07-22 2019-11-12 江苏云意电气股份有限公司 一种igbt退饱和保护和驱动电源欠压保护电路
CN111786368A (zh) * 2020-07-13 2020-10-16 珠海格力智能装备有限公司 断电保护电路与电子设备
CN112217179A (zh) * 2020-10-23 2021-01-12 北京精密机电控制设备研究所 一种用于外骨骼机器人的开关及保护电路
CN112242692A (zh) * 2019-07-18 2021-01-19 浙江宇视科技有限公司 一种过流保护电路及电源电路
CN112467689A (zh) * 2020-11-05 2021-03-09 瑞芯微电子股份有限公司 一种过压保护装置
CN113163243A (zh) * 2020-01-22 2021-07-23 海信视像科技股份有限公司 显示装置
CN113778212A (zh) * 2021-09-15 2021-12-10 天津通广集团振通电子有限公司 固态存储介质电源失效保护装置
CN113872147A (zh) * 2021-11-10 2021-12-31 珠海格力智能装备有限公司 过压保护电路及具有其的控制器
CN113885636A (zh) * 2021-11-05 2022-01-04 安徽海勤科技有限公司 一种输入电压范围可调保护电路
CN116885669A (zh) * 2023-09-08 2023-10-13 广东东菱电源科技有限公司 一种由mcu控制输入电压过压欠压保护电路

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106786456A (zh) * 2016-12-15 2017-05-31 李小司 一种安全稳定的伸缩门控制器
CN109818343B (zh) * 2017-11-20 2021-06-08 深圳光峰科技股份有限公司 一种过压保护电路及投影机
CN108270199B (zh) * 2018-03-28 2023-12-12 广州金升阳科技有限公司 一种输出过压保护电路
CN112433022A (zh) * 2019-08-26 2021-03-02 无锡统安安全科技有限公司 防爆多继电器气体探测器
CN117460123B (zh) * 2023-12-26 2024-03-15 深圳莱福德科技股份有限公司 一种led驱动电源防止空载失控的方法

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN200976485Y (zh) * 2006-11-30 2007-11-14 青岛海信电器股份有限公司 欠压保护电路
CN201138747Y (zh) * 2008-01-04 2008-10-22 深圳晶辰电子科技股份有限公司 开关电源交流输入过欠压保护电路
CN203026918U (zh) * 2012-11-29 2013-06-26 无锡市金赛德电子有限公司 一种智能电网终端电源输入过压保护电路
CN203166467U (zh) * 2013-03-20 2013-08-28 向智勇 一种过压保护电路
CN203553906U (zh) * 2013-10-09 2014-04-16 珠海格力电器股份有限公司 开关电源输入电压保护电路

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN200976485Y (zh) * 2006-11-30 2007-11-14 青岛海信电器股份有限公司 欠压保护电路
CN201138747Y (zh) * 2008-01-04 2008-10-22 深圳晶辰电子科技股份有限公司 开关电源交流输入过欠压保护电路
CN203026918U (zh) * 2012-11-29 2013-06-26 无锡市金赛德电子有限公司 一种智能电网终端电源输入过压保护电路
CN203166467U (zh) * 2013-03-20 2013-08-28 向智勇 一种过压保护电路
CN203553906U (zh) * 2013-10-09 2014-04-16 珠海格力电器股份有限公司 开关电源输入电压保护电路

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
ZHANG, XIGENG ET AL.: "Protection System Design Of Two Phase Inverter", POWER ELECTRONICS, 30 November 1997 (1997-11-30), pages 64 *

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107124022A (zh) * 2017-06-14 2017-09-01 中能易电新能源技术有限公司 蓄电池充电保护电路
CN108110835A (zh) * 2017-12-27 2018-06-01 苏州易美新思新能源科技有限公司 一种用于高压电池系统的低功耗控制电路
CN108110835B (zh) * 2017-12-27 2023-11-24 苏州易美新思新能源科技有限公司 一种用于高压电池系统的低功耗控制电路
CN108919728A (zh) * 2018-08-23 2018-11-30 深圳和而泰智能控制股份有限公司 一种控制电路
CN108919728B (zh) * 2018-08-23 2023-09-26 深圳和而泰智能控制股份有限公司 一种控制电路
CN109450031A (zh) * 2018-12-03 2019-03-08 京信通信系统（中国）有限公司 一种电池过放电保护电路
CN109546847A (zh) * 2019-01-16 2019-03-29 合肥惠科金扬科技有限公司 开关电源的同步关断电路、驱动电路及同步关断方法
CN109888738A (zh) * 2019-01-25 2019-06-14 惠州三华工业有限公司 自锁式输出过压保护电路及电压输出系统
CN109888738B (zh) * 2019-01-25 2024-04-19 惠州三华工业有限公司 自锁式输出过压保护电路及电压输出系统
CN109672255A (zh) * 2019-02-25 2019-04-23 威胜信息技术股份有限公司 后备电容充放电电路、充放电方法及其故障指示器
CN109672255B (zh) * 2019-02-25 2024-09-10 威胜信息技术股份有限公司 后备电容充放电电路、充放电方法及其故障指示器
CN109757020B (zh) * 2019-03-12 2023-08-15 江苏北方湖光光电有限公司 一种基于微光保护的控制电路
CN109757020A (zh) * 2019-03-12 2019-05-14 江苏北方湖光光电有限公司 一种基于微光保护的控制电路
CN112242692A (zh) * 2019-07-18 2021-01-19 浙江宇视科技有限公司 一种过流保护电路及电源电路
CN112242692B (zh) * 2019-07-18 2022-10-04 浙江宇视科技有限公司 一种过流保护电路及电源电路
CN110445100A (zh) * 2019-07-22 2019-11-12 江苏云意电气股份有限公司 一种igbt退饱和保护和驱动电源欠压保护电路
CN113163243A (zh) * 2020-01-22 2021-07-23 海信视像科技股份有限公司 显示装置
CN113163243B (zh) * 2020-01-22 2022-12-13 海信视像科技股份有限公司 显示装置
CN111786368A (zh) * 2020-07-13 2020-10-16 珠海格力智能装备有限公司 断电保护电路与电子设备
CN112217179B (zh) * 2020-10-23 2022-12-27 北京精密机电控制设备研究所 一种用于外骨骼机器人的开关及保护电路
CN112217179A (zh) * 2020-10-23 2021-01-12 北京精密机电控制设备研究所 一种用于外骨骼机器人的开关及保护电路
CN112467689A (zh) * 2020-11-05 2021-03-09 瑞芯微电子股份有限公司 一种过压保护装置
CN113778212A (zh) * 2021-09-15 2021-12-10 天津通广集团振通电子有限公司 固态存储介质电源失效保护装置
CN113885636B (zh) * 2021-11-05 2022-12-20 安徽海勤科技有限公司 一种输入电压范围可调保护电路
CN113885636A (zh) * 2021-11-05 2022-01-04 安徽海勤科技有限公司 一种输入电压范围可调保护电路
CN113872147A (zh) * 2021-11-10 2021-12-31 珠海格力智能装备有限公司 过压保护电路及具有其的控制器
CN116885669A (zh) * 2023-09-08 2023-10-13 广东东菱电源科技有限公司 一种由mcu控制输入电压过压欠压保护电路
CN116885669B (zh) * 2023-09-08 2024-01-12 广东东菱电源科技有限公司 一种由mcu控制输入电压过压欠压保护电路

Also Published As

Publication number Publication date
CN104577993A (zh) 2015-04-29
CN104577993B (zh) 2018-11-09

Similar Documents

Publication Publication Date Title
WO2015051688A1 (zh) 开关电源输入电压保护电路
TWI574480B (zh) 過電流保護電路以及其伺服器
CN202513543U (zh) 一种过流保护电路
CN103474954B (zh) 一种基于三端可调分流基准源的过压及欠压保护电路
CN202373957U (zh) 过压及欠压保护电路
CN207398814U (zh) 欠压过压保护电路和供电系统
CN201629569U (zh) Usb接口过压保护电路
CN104218558A (zh) 防浪涌高压保护电路
CN204886121U (zh) 可自动恢复的快速过流保护电路
WO2017206082A1 (zh) 一种 dc-dc 电源及其低压关断控制电路
CN203800576U (zh) 一种mos管输出过流、欠流保护电路
US8767365B2 (en) Protection circuit
CN203553906U (zh) 开关电源输入电压保护电路
CN203690913U (zh) 一种带短路保护的防反接装置
CN113690845B (zh) 电源输出保护控制装置
CN109066598A (zh) 一种低电平触发自锁电路
CN203562754U (zh) 一种基于三端可调分流基准源的过压及欠压保护电路
CN208753973U (zh) 一种低电平触发自锁电路
CN205726196U (zh) 一种地面广播机顶盒tuner供电电路
CN103091543B (zh) 电流检测电路、恒流电路和电池充放电保护系统
CN202977969U (zh) 一种激光器耦合电源的高效保护电路
CN203522162U (zh) 欠压保护及过流保护电路
CN207939194U (zh) 一种过压保护电路
CN110676801A (zh) 防震荡过压保护电路
CN206212156U (zh) 一种防止雷击测试误保护电路及电视机

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14851597

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14851597

Country of ref document: EP

Kind code of ref document: A1