WO2016082302A1 - 一种led驱动输出端电容的保护电路 - Google Patents

一种led驱动输出端电容的保护电路 Download PDF

Info

Publication number
WO2016082302A1
WO2016082302A1 PCT/CN2015/000823 CN2015000823W WO2016082302A1 WO 2016082302 A1 WO2016082302 A1 WO 2016082302A1 CN 2015000823 W CN2015000823 W CN 2015000823W WO 2016082302 A1 WO2016082302 A1 WO 2016082302A1
Authority
WO
WIPO (PCT)
Prior art keywords
protection circuit
capacitor
switching element
output terminal
output
Prior art date
Application number
PCT/CN2015/000823
Other languages
English (en)
French (fr)
Inventor
刁显江
Original Assignee
欧普照明股份有限公司
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 欧普照明股份有限公司 filed Critical 欧普照明股份有限公司
Priority to EP15863014.5A priority Critical patent/EP3211970A1/en
Publication of WO2016082302A1 publication Critical patent/WO2016082302A1/zh
Priority to US15/603,114 priority patent/US10321538B2/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B47/00—Circuit arrangements for operating light sources in general, i.e. where the type of light source is not relevant
    • H05B47/20—Responsive to malfunctions or to light source life; for protection
    • H05B47/24—Circuit arrangements for protecting against overvoltage
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B45/00—Circuit arrangements for operating light-emitting diodes [LED]
    • H05B45/50—Circuit arrangements for operating light-emitting diodes [LED] responsive to malfunctions or undesirable behaviour of LEDs; responsive to LED life; Protective circuits

Definitions

  • the invention relates to an LED driving circuit, in particular to a protection circuit for an LED driving output terminal capacitance.
  • the LED drive circuit has a fixed output circuit topology, and the output terminal has a capacitive component, such as a buck circuit topology, which has a simple circuit structure and a low overall structure cost, and is widely used in LED self-rectifying lamps.
  • the usual LED driver circuit may have the following two abnormal conditions: 1.
  • the power tube is abnormally short-circuited; 2.
  • the output is open (caused by abnormality such as LED damage, output line disconnection, etc.). These abnormal conditions can cause the output voltage to become very large, resulting in damage to the output capacitor.
  • a protection circuit for an LED driving output terminal capacitor the protection circuit being connected to two sides of the output terminal capacitor, including a switching element, a voltage dividing unit, and a one-way conduction unit.
  • the switching element is connected in parallel with the output terminal capacitor, and the unidirectional conduction unit is connected between the switching element and the output terminal capacitor, and the switching element is turned on when the voltage exceeds a threshold value, thereby
  • the output capacitor is short-circuited at both ends to prevent an excessive voltage from being applied to the output terminal capacitor, and the one-way conduction unit allows the current to flow from the protection circuit to the output terminal.
  • the protection circuit further includes a threshold voltage conducting unit, and the threshold voltage conducting unit is connected to the The voltage dividing unit and the switching element are turned on when a voltage across the protection circuit exceeds a certain value.
  • the threshold voltage conducting unit is a triode.
  • the protection circuit further includes a filter capacitor, wherein the filter capacitor is connected at one end between the threshold voltage conduction unit and the switching element, and the other end is connected to the capacitor element and the output terminal.
  • the unidirectional conduction unit is a diode.
  • the switching element is a thyristor.
  • the protection capacitor is used for the output of the buck topology circuit.
  • the LED drive comprises an LED drive circuit having a buck topology circuit.
  • the protection circuit of the LED driving output terminal capacitor of the invention has the following advantages: the output terminal capacitance can be effectively protected, and the current can be reversed when the output terminal capacitance has a large voltage, thereby damaging the protection circuit. Switching element in the middle.
  • FIG. 1 is a circuit diagram of a preferred embodiment of a protection circuit for an LED driver output terminal capacitor of the present invention.
  • FIG. 2 is a circuit diagram of a preferred embodiment of an LED driving circuit of the present invention.
  • a protection circuit 1 for driving an output capacitor of an LED is provided.
  • the protection circuit 1 is connected to both sides of the output capacitor EC1, and includes a switching element SCR1, a voltage dividing unit 11 and a one-way unit D2.
  • the switching element SCR1 is connected in parallel with the output terminal capacitance EC1, and the one-way conduction unit D2 is connected between the switching element SCR1 and the output terminal capacitance EC1.
  • the switching element SCR1 is turned on when the voltage exceeds the threshold value, thereby short-circuiting the output terminal capacitance EC1.
  • the one-way conduction unit D2 allows current to self-protection circuit 1
  • the single-conductor flows to the output capacitor EC1.
  • the one-way conduction unit D2 prevents the voltage released across the output terminal capacitance EC1 from being reversely loaded to the protection circuit 1 so that the switching element SCR1 of the protection circuit 1 is not damaged by excessive voltage.
  • the elements referred to in the present invention are not limited to only one single electronic component, and may be circuits including a plurality of electronic components.
  • the switching element SCR1 is a thyristor. In other embodiments, the switching element SCR1 can be designed as other components or circuits having a threshold voltage conduction function as needed.
  • the unidirectional conduction unit D2 is a diode. In other embodiments, the unidirectional conduction unit D2 may be another component or circuit capable of achieving a single conduction.
  • the protection circuit 1 further includes a threshold voltage conduction unit ZD1.
  • the threshold voltage conduction unit ZD1 is connected between the voltage dividing unit 10 and the switching element SCR1, and is turned on when the voltage across the protection circuit 1 exceeds a certain value.
  • the threshold voltage conducting unit ZD1 is turned on, thereby turning on the switching element SCR1.
  • the threshold voltage conduction unit ZD1 is a triode, and the specific one is a voltage regulator triode. Therefore, the conduction condition can be realized by selecting different voltage regulator triodes according to requirements, which is convenient and simple.
  • the threshold voltage conducting unit ZD1 may also be other components or circuits capable of achieving threshold voltage conduction.
  • the voltage dividing unit 11 includes a first resistor R1 and a second resistor R2. One end of the threshold voltage conducting unit ZD1 is connected to the switching element SCR1, and the other end is connected between the first resistor R1 and the second resistor R2. In other embodiments, the voltage dividing unit 11 can also be adjusted as needed.
  • the protection circuit 1 further includes a filter capacitor C2.
  • One end of the filter capacitor C2 is connected between the threshold voltage conduction unit ZD1 and the switching element SCR1, and the other end is connected to the junction of the switching element SCR1 and the output terminal capacitor EC1.
  • the filter capacitor C2 is used to prevent the noise circuit from causing the protection circuit 1 to malfunction.
  • the protection circuit 1 of the LED driving output terminal of the present invention is mostly used for the output of the LED driving circuit 3 having the buck topology circuit 2.
  • the protection of the LED drive output capacitor of the present invention Circuit 1 can also be used for other topological circuits.
  • the output voltage is normal.
  • the threshold voltage conduction unit ZD1 cannot be broken.
  • the switching element SCR1 is lower than the trigger threshold and is in the off state, and the line works normally.
  • the output voltage rises, and the output voltage divided by the first resistor R1 and the second resistor R2 breaks through the threshold voltage conduction unit ZD1, and the switching element SCR1 reaches the trigger threshold. , thus conducting, so that no excessive voltage is applied to the output capacitor EC1.
  • the one-way conduction unit D2 blocks the stored energy back-input switching element SCR1 on the output terminal capacitor EC1, thereby preventing the switching element SCR1 from being damaged due to excessive current at the moment of turning on the short circuit.
  • the transistor Q1 of the LED driving circuit 3 is damaged, and when the emitter and the base are short-circuited, the output voltage of the first resistor R1 and the second resistor R2 is broken, and the threshold voltage is turned on.
  • the switching element SCR1 reaches the trigger threshold value and is turned on. Since the input power becomes larger, the fuse RF1 of the LED driving circuit is opened, and the mains input is disconnected, thereby realizing protection of the output terminal capacitance EC1.
  • the one-way conduction unit D2 blocks the stored energy back-input switching element SCR1 on the output terminal capacitor EC1, thereby preventing the switching element SCR1 from being damaged due to excessive current at the moment of turning on the short circuit.

Landscapes

  • Circuit Arrangement For Electric Light Sources In General (AREA)
  • Led Devices (AREA)

Abstract

一种LED驱动输出端电容的保护电路(1)，所述保护电路连接于所述输出端电容(EC1)两侧，包括开关元件(SCR1)、分压单元(11)以及单向导通单元(D2)，所述开关元件(SCR1)与所述输出端电容(EC1)并联，所述单向导通单元(D2)连接于所述开关元件(SCR1)与所述输出端电容(EC1)之间，所述开关元件(SCR1)在电压超过门限值时导通，从而将所述输出端电容(EC1)两端短路，阻止过大电压加载于所述输出端电容(EC1)，所述单向导通单元(D2)允许所述电流自所述保护电路(1)单向导通流向所述输出端电容(EC1)。

Description

一种LED驱动输出端电容的保护电路 技术领域
本发明涉及一种LED驱动电路，尤其指LED驱动输出端电容的保护电路。
技术背景
LED驱动电路多具有固定的输出电路拓扑，而输出端具有电容元件，如降压电路拓扑，其线路架构简单，整体结构成本低廉，广泛的使用在LED自整流灯上。但是，通常的LED驱动电路可能出现如下两种异常状况：1.功率管异常短路；2.输出开路(由LED损坏，输出线断开等等异常情况导致)。而这些异常情况会造成输出端电压变得很大，从而造成输出端电容的损坏。
因此，为了克服上述缺陷，有必要提供一种改进的LED驱动输出端电容的保护电路以保护输出端电容。
发明概要
本发明的目的在于提供一种LED驱动输出端电容的保护电路。
为了实现上述目的，本发明采用如下技术方案：一种LED驱动输出端电容的保护电路，所述保护电路连接于所述输出端电容两侧，包括开关元件、分压单元以及单向导通单元，所述开关元件与所述输出端电容并联，所述单向导通单元连接于所述开关元件与所述输出端电容之间，所述开关元件在电压超过门限值时导通，从而将所述输出端电容两端短路，阻止过大电压加载于所述输出端电容，所述单向导通单元允许所述电流自所述保护电路单向导通流向所述输出端电容。
优选地，所述保护电路还包括门限电压导通单元，所述门限电压导通单元连接于所 述分压单元与所述开关元件之间，在所述保护电路两端的电压超过一定值时导通。
优选地，所述门限电压导通单元为三极管。
优选地，所述保护电路还包括滤波电容，所述滤波电容一端连接于所述门限电压导通单元和所述开关元件之间，另一端连接所述开关元件与所述输出端电容连接处。
优选地，所述单向导通单元为二极管。
优选地，所述开关元件为晶闸管。
优选地，所述保护电容用于降压拓扑电路的输出端。
优选地，所述LED驱动包括具有降压拓扑电路的LED驱动电路。
相较于现有技术，本发明LED驱动输出端电容的保护电路有以下优点：既能够有效的保护输出端电容，又能够在输出端电容具有较大电压时，不会电流倒流而损坏保护电路中的开关元件。
附图说明
图1为本发明LED驱动输出端电容的保护电路的较佳实施例的电路图。
图2为本发明LED驱动电路的较佳实施例的电路图。
发明内容
请参照图1所示，本发明一种LED驱动输出端电容的保护电路1，保护电路1连接于输出端电容EC1两侧，包括开关元件SCR1、分压单元11以及单向导通单元D2。开关元件SCR1与输出端电容EC1并联，单向导通单元D2连接于开关元件SCR1与输出端电容EC1之间，开关元件SCR1在电压超过门限值时导通，从而将输出端电容EC1两端短路，阻止过大电压加载于输出端电容EC1，单向导通单元D2允许电流自保护电路1 单向导通流向输出端电容EC1。同时，单向导通单元D2阻止输出端电容EC1两端释放的电压反向加载于保护电路1从而使保护电路1的开关元件SCR1不会因电压过大而损坏。本发明中所指的元件，并非仅指单独的一个电子元件，也可以是包括多个电子元件的电路。
本实施例中，开关元件SCR1为晶闸管，其他实施例中，可以根据需要将开关元件SCR1设计为具有门限电压导通功能的其他元件或电路。
本实施例中，单向导通单元D2为二极管，其他实施例中，单向导通单元D2也可以为能够实现单向导通的其他元件或电路。
保护电路1还包括门限电压导通单元ZD1，门限电压导通单元ZD1连接于分压单元10与开关元件SCR1之间，在保护电路1两端的电压超过一定值时导通。分压单元10分压后的电压超过一定值时，门限电压导通单元ZD1导通，从而使开关元件SCR1导通。本实施例中，门限电压导通单元ZD1为三极管，具体的为稳压三极管，因此导通条件可以根据需要选择不同的稳压三极管来实现，方便、简单。其他实施例中，门限电压导通单元ZD1，也可以为其他能够实现门限电压导通的元件或电路。
本实施例中，分压单元11包括第一电阻R1和第二电阻R2，门限电压导通单元ZD1的一端与开关元件SCR1连接，另一端连接于第一电阻R1和第二电阻R2之间。其他实施例中，分压单元11也可以根据需要调整。
保护电路1还包括滤波电容C2，滤波电容C2一端连接于门限电压导通单元ZD1和开关元件SCR1之间，另一端连接开关元件SCR1与输出端电容EC1连接处。滤波电容C2用于防止干扰杂讯信号引起保护电路1误动作。
请参照图2所示，本发明LED驱动输出端电容的保护电路1多用于具有降压拓扑电路2的LED驱动电路3的输出端。其他实施例中，本发明LED驱动输出端电容的保护 电路1也可以用于其他拓扑电路。
线路正常工作时，输出电压正常，第一电阻R1和第二电阻R2分压后不能击穿门限电压导通单元ZD1，开关元件SCR1低于触发门限值，处于截止状态，线路正常工作。
线路出现异常情况时(例如输出开路状态等)，输出电压升高，第一电阻R1和第二电阻R2分压后的输出电压击穿门限电压导通单元ZD1，开关元件SCR1达到触发门限值，从而导通，从而使得不会有过大的电压加载于输出端电容EC1。同时单向导通单元D2阻挡输出端电容EC1上的存储能量反灌开关元件SCR1，从而防止开关元件SCR1由于导通短路瞬间电流过大引起损坏。
又例如当电路线路出现另一种异常情况，LED驱动电路3的三极管Q1损坏，发射极和基极短路时，第一电阻R1和第二电阻R2分压后的输出电压击穿门限电压导通单元ZD1，开关元件SCR1达到触发门限值，从而导通，由于输入功率变大，则LED驱动电路的保险丝RF1则开路，断开市电输入，从而实现对输出端电容EC1的保护。同时单向导通单元D2阻挡输出端电容EC1上的存储能量反灌开关元件SCR1，从而防止开关元件SCR1由于导通短路瞬间电流过大引起损坏。
应当注意的是，本发明的实施例有较佳的实施性，且并非对本发明作任何形式的限制，任何熟悉该领域的技术人员可能利用上述揭示的技术内容变更或修饰为等同的有效实施例，但凡未脱离本发明技术方案的内容，依据本发明的技术实质对以上实施例所作的任何修改或等同变化及修饰，均仍属于本发明技术方案的范围内。

Claims (8)

  1. 一种LED驱动输出端电容的保护电路，所述保护电路连接于所述输出端电容两侧，包括开关元件、分压单元以及单向导通单元，所述开关元件与所述输出端电容并联，所述单向导通单元连接于所述开关元件与所述输出端电容之间，所述开关元件在电压超过门限值时导通，从而将所述输出端电容两端短路，阻止过大电压加载于所述输出端电容，所述单向导通单元允许所述电流自所述保护电路单向导通流向所述输出端电容。
  2. 如权利要求1所述的LED驱动输出端电容的保护电路，其特征在于：所述保护电路还包括门限电压导通单元，所述门限电压导通单元连接于所述分压单元与所述开关元件之间，在所述保护电路两端的电压超过一定值时导通。
  3. 如权利要求2所述的LED驱动输出端电容的保护电路，其特征在于：所述门限电压导通单元为三极管。
  4. 如权利要求3所述的LED驱动输出端电容的保护电路，其特征在于：所述保护电路还包括滤波电容，所述滤波电容一端连接于所述门限电压导通单元和所述开关元件之间，另一端连接所述开关元件与所述输出端电容连接处。
  5. 如权利要求1所述的LED驱动输出端电容的保护电路，其特征在于：所述单向导通单元为二极管。
  6. 如权利要求1所述的LED驱动输出端电容的保护电路，其特征在于：所述开关元件为晶闸管。
  7. 如权利要求6所述的LED驱动输出端电容的保护电路，其特征在于：所述保护电容用于降压拓扑电路的输出端。
  8. 如权利要求7所述的LED驱动输出端电容的保护电路，其特征在于：所述LED驱动包括具有降压拓扑电路的LED驱动电路。
PCT/CN2015/000823 2014-11-25 2015-11-27 一种led驱动输出端电容的保护电路 WO2016082302A1 (zh)

Priority Applications (2)

Application Number Priority Date Filing Date Title
EP15863014.5A EP3211970A1 (en) 2014-11-25 2015-11-27 Led driving output end capacitor protection circuit
US15/603,114 US10321538B2 (en) 2014-11-25 2017-05-23 Protective circuit for output terminal capacitor of light-emitting diode (LED) driver

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN201410690465.4 2014-11-25
CN201410690465.4A CN104411051A (zh) 2014-11-25 2014-11-25 一种led驱动输出端电容的保护电路

Related Child Applications (1)

Application Number Title Priority Date Filing Date
US15/603,114 Continuation US10321538B2 (en) 2014-11-25 2017-05-23 Protective circuit for output terminal capacitor of light-emitting diode (LED) driver

Publications (1)

Publication Number Publication Date
WO2016082302A1 true WO2016082302A1 (zh) 2016-06-02

Family

ID=52648631

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2015/000823 WO2016082302A1 (zh) 2014-11-25 2015-11-27 一种led驱动输出端电容的保护电路

Country Status (4)

Country Link
US (1) US10321538B2 (zh)
EP (1) EP3211970A1 (zh)
CN (1) CN104411051A (zh)
WO (1) WO2016082302A1 (zh)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104411051A (zh) * 2014-11-25 2015-03-11 欧普照明股份有限公司 一种led驱动输出端电容的保护电路
CN105162454B (zh) * 2015-10-12 2020-04-28 索尔思光电（成都）有限公司 一种光模块及其信号输出端口、信号输出端口保护电路

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100090604A1 (en) * 2008-10-09 2010-04-15 Yasuhiro Maruyama Led drive circuit, led illumination component, led illumination device, and led illumination system
CN202197098U (zh) * 2011-09-09 2012-04-18 深圳市澳磁电源科技有限公司 一种过压保护电路、led驱动电源及led照明装置
CN203352856U (zh) * 2013-06-24 2013-12-18 合肥龙多电子科技有限公司 带开路保护的电容降压led照明电源
CN104411051A (zh) * 2014-11-25 2015-03-11 欧普照明股份有限公司 一种led驱动输出端电容的保护电路
CN204859603U (zh) * 2014-11-25 2015-12-09 欧普照明股份有限公司 一种led驱动输出端电容的保护电路

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010043499A1 (en) * 2008-10-13 2010-04-22 Audioasics A/S A multi-state dc-dc converter
CN103683885B (zh) * 2013-12-12 2017-02-15 安伏（苏州）电子有限公司 防止电流反灌和输出电容放电的装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20100090604A1 (en) * 2008-10-09 2010-04-15 Yasuhiro Maruyama Led drive circuit, led illumination component, led illumination device, and led illumination system
CN202197098U (zh) * 2011-09-09 2012-04-18 深圳市澳磁电源科技有限公司 一种过压保护电路、led驱动电源及led照明装置
CN203352856U (zh) * 2013-06-24 2013-12-18 合肥龙多电子科技有限公司 带开路保护的电容降压led照明电源
CN104411051A (zh) * 2014-11-25 2015-03-11 欧普照明股份有限公司 一种led驱动输出端电容的保护电路
CN204859603U (zh) * 2014-11-25 2015-12-09 欧普照明股份有限公司 一种led驱动输出端电容的保护电路

Also Published As

Publication number Publication date
US20170257915A1 (en) 2017-09-07
CN104411051A (zh) 2015-03-11
US10321538B2 (en) 2019-06-11
EP3211970A1 (en) 2017-08-30

Similar Documents

Publication Publication Date Title
JP2017529046A5 (zh)
EP2706639B1 (en) Surge protection circuit
US9083181B2 (en) Over-current protection circuit for light source driving module and related backlight module
JP5708817B2 (ja) 負荷駆動回路
TWI532286B (zh) Discharge circuit
JP2015500566A5 (zh)
US8780513B2 (en) Reverse battery cutoff circuit for an actuator or the like
TW201530999A (zh) 具有過電流與過電壓保護功能的升壓裝置
CN109067161B (zh) 一种电源安全启动系统
TWI524638B (zh) 升壓轉換器及其供電控制方法
TWI485948B (zh) 電力系統及其短路保護電路
WO2016082302A1 (zh) 一种led驱动输出端电容的保护电路
JP6103719B2 (ja) 自動車の高エネルギートランジエントから電子制御ユニットを保護するための保護回路
WO2021056917A1 (zh) 一种直流电源并机输入防反接电路及服务器系统
US8237420B2 (en) Inrush current suppressing circuit and electronic device using the same
JP6048164B2 (ja) 過電流保護回路
JP2011135665A (ja) 保護装置
WO2017190430A1 (zh) 升压型直流-直流转换器
TWI641197B (zh) 電池狀態監視電路及電池裝置
US9065445B2 (en) Voltage clamp assist circuit
JP2008270813A5 (zh)
CN204859603U (zh) 一种led驱动输出端电容的保护电路
JP2019047301A5 (zh)
KR20170096424A (ko) 서지 보호회로
KR101147258B1 (ko) 포지티브 직류전원 과부하 차단회로

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: 15863014

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

REEP Request for entry into the european phase

Ref document number: 2015863014

Country of ref document: EP