WO2008067686A1 - Protection circuit for single-board dc power source interface - Google Patents

Protection circuit for single-board dc power source interface Download PDF

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Publication number
WO2008067686A1
WO2008067686A1 PCT/CN2006/003261 CN2006003261W WO2008067686A1 WO 2008067686 A1 WO2008067686 A1 WO 2008067686A1 CN 2006003261 W CN2006003261 W CN 2006003261W WO 2008067686 A1 WO2008067686 A1 WO 2008067686A1
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Prior art keywords
node
protection circuit
current
power source
circuit according
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PCT/CN2006/003261
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French (fr)
Chinese (zh)
Inventor
Xiaogang Li
Jing Shi
Xiangyu Tang
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Zte Corporation
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Priority to PCT/CN2006/003261 priority Critical patent/WO2008067686A1/en
Publication of WO2008067686A1 publication Critical patent/WO2008067686A1/en

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    • 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
    • H02H9/041—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess voltage using a short-circuiting device

Definitions

  • the present invention relates to protection of a DC power port, and more particularly to a protection circuit for a single-board DC power port.
  • Background Art Due to lightning strikes, overvoltage of a power system, etc., even if the overcurrent overcurrent protection of the power supply device is passed, the DC power supply communication device may be subjected to a surge of a certain amount of energy at the DC port.
  • the single-board DC power port needs to set the surge absorbing circuit of the corresponding energy level.
  • the main application circuits for protection against surge and reverse power supply damage of single-board DC power ports are as follows. The following is a description of the -48V DC power input protection circuit.
  • Figure 1 shows a -48V DC power input protection circuit consisting of fuse FU1 and Transient Voltage Suppressor (TVS) D1.
  • D1 is used for surge absorption, and when the DC power supply is reversed, D1 is forward-conducting, and the overcurrent causes FU1 to operate.
  • the problem with this circuit is that the FU1 action generates a thermal shock after the DC power supply is connected, and the FU1 needs to be restored or replaced, increasing the maintenance cost.
  • the DC power supply is reversed and immediately impacts the subsequent power input circuit.
  • FIG. 2 shows a -48V DC power input protection circuit consisting of fuse FU1, rectifier diode D2 and silicon transient voltage absorbing diode (TVS) D1.
  • D2 is used for anti-reverse connection of DC power supply
  • D1 is used for surge absorption.
  • the problem with this circuit is that the anti-reverse diode is not conducive to surge bleed before the TVS. Because, if the reverse breakdown voltage of the anti-reverse diode is too high, the surge current may cause impact damage to the device through the subsequent discharge of the power supply; if the reverse breakdown voltage of the anti-reverse diode is low, the surge must break through the TVS one after another.
  • a primary object of the present invention is to provide a protection circuit for a DC power port of a single board, which overcomes the shortcomings of the prior art in which the device and the subsequent circuit are affected by the impact, and solves the reliability defects existing in the prior art. Comprehensive and reasonable solution to the problem of anti-surge and reverse power supply damage of the board-level DC power port.
  • the present invention provides a protection circuit for a single-board DC power port.
  • the protection circuit comprises: a first input for flowing a direct current; a second input for flowing a direct current; and a surge absorbing unit connected between the first node and the second node for preventing surges,
  • the first node is connected to the current inflow end of the subsequent circuit
  • the anti-reverse diode is connected between the current outlet end of the second node and the subsequent circuit for preventing reverse connection damage of the power source, and the positive pole of the anti-reverse diode is connected to the subsequent circuit a current outflow end, the negative pole of the anti-reverse diode is connected to the second node
  • an overcurrent protection unit connected between the second input end and the second node, or connected between the first input end and the first node, wherein When the overcurrent protection unit is connected between the second input terminal and the second node, the first node is connected to the first input end, and when the overcurrent protection unit is connected between the first input end and the first node, The two nodes are connected to the second input.
  • the surge absorbing unit can be a two-way surge absorbing element.
  • the surge absorbing unit is a bidirectional stone transient voltage absorbing diode or varistor.
  • the breakdown voltage of the surge absorbing unit is higher than the highest operating voltage of the DC power source, and the peak monthly current is determined based on the surge level.
  • the anti-reverse diode can be a rectifier diode. Further, the reverse breakdown voltage of the anti-reverse diode is higher than the highest operating voltage of the DC power supply, and the forward operating current exceeds the rated operating current of the single board.
  • the overcurrent protection unit can be an overcurrent fuse element.
  • the overcurrent protection unit is a fuse or a fuse.
  • the rated voltage of the overcurrent protection unit is greater than or equal to the maximum operating voltage of the DC power source, and the rated current is determined according to the rated operating current of the board, the working environment temperature, the derating design coefficient, and the peak pulse current of the surge absorbing unit.
  • the overcurrent protection unit is a slow melt device.
  • the DC power source is a DC power source that is grounded, and the overcurrent protection unit is connected between the second input end and the second node.
  • the DC power supply can be -48V.
  • the DC power source is a negatively grounded DC power source, and the overcurrent protection unit is connected between the first input end and the first node.
  • the DC power supply can be 24V or 12V.
  • FIG. 1 is a circuit diagram of a DC power input protection circuit 1 in the prior art
  • FIG. 2 is a circuit diagram of a DC power input protection circuit 2 in the prior art
  • FIG. 3 is a single-board DC power supply according to the present invention
  • FIG. 4 is a functional block diagram of a DC power surge protection circuit that is grounded in accordance with an embodiment of the present invention
  • FIG. 5 is a functional block diagram of a DC power surge protection circuit with a negative ground according to an embodiment of the present invention.
  • 6 is a DC power input surge waveform diagram according to an embodiment of the present invention
  • FIG. 7 is a residual surge waveform diagram before an anti-reverse diode according to an embodiment of the present invention
  • FIG. 8 is a waveform diagram of the DC power supply input -48V connected in front of the anti-reverse diode according to an embodiment of the present invention
  • FIG. 9 is a diagram of the DC power supply input -48V reversed after the anti-reverse diode according to the embodiment of the present invention
  • FIG. 10 is a circuit diagram of a -48 V DC power surge protection circuit according to an embodiment of the present invention
  • FIG. 11 is a circuit diagram of a 24 V DC power surge protection circuit according to an embodiment of the present invention
  • FIG. 12 is an implementation according to the present invention.
  • a protection circuit for a single-board DC power port includes: a first input terminal 11 for flowing a direct current; a second input terminal 12 for flowing a direct current; and a surge absorbing unit 21 connected to Between the first node and the second node, for preventing surge, wherein the first node is connected to the current inflow end of the subsequent circuit; the anti-reverse diode 22 is connected between the current outflow end of the second node and the subsequent circuit, For preventing reverse connection damage, the anode of the anti-reverse diode 22 is connected to the current outflow terminal of the subsequent circuit, the cathode of the anti-reverse diode 22 is connected to the second node; and the overcurrent protection unit 30 is connected to the second input terminal 12 and Between the second node, or connected between the first input end 11 and the first node, wherein when the overcurrent protection unit 30 is connected between the second input end 12 and the second node, the first node is connected to the first node An input terminal 11 is connected to the second
  • the surge absorbing unit 21 may be a two-way surge absorbing element.
  • the surge absorbing unit 21 is a bidirectional transient voltage absorbing diode or a varistor.
  • the breakdown voltage of the surge absorbing unit 21 is higher than the highest operating voltage of the DC power source, and the peak pulse current is determined based on the surge level.
  • the anti-reverse diode 22 can be a rectifier diode. Further, the reverse breakdown voltage of the anti-reverse diode 22 is higher than the highest operating voltage of the DC power supply, and the forward operating current exceeds the rated operating current of the single board.
  • the overcurrent protection unit 30 can be an overcurrent fuse element.
  • the overcurrent protection unit 30 is a fuse or a fuse.
  • the rated voltage of the overcurrent protection unit 30 is greater than or equal to the highest operating voltage of the DC power source, and the rated current is determined by the rated operating current of the board, the working environment temperature, the derating design coefficient, and the peak current of the surge absorbing unit 21. .
  • the overcurrent protection unit 30 is a slow melting device.
  • the DC power source is a DC power source that is grounded, and the overcurrent protection unit 30 is connected between the second input terminal 12 and the second node.
  • the DC power supply can be -48V.
  • the DC power source is a negatively grounded DC power source, and the overcurrent protection unit 30 is connected between the first input terminal 11 and the first node.
  • the DC power supply can be 24V or 12V.
  • the invention relates to a protection against surge and reverse power supply damage of a single-board DC power port of a communication device for DC power supply or other electronic devices using these DC power sources. It is applicable not only to plug-in boards that introduce power through the backplane of the power supply unit, but also to desktop boards that have external power leads.
  • Figure 4 is a functional block diagram of a surge protection circuit for a DC power supply (such as -48V) that is grounded.
  • Figure 5 is a functional block diagram of a negative-grounded DC power supply (such as 24V) surge protection circuit. Referring to FIG. 4 and FIG. 5, the technical solution according to the present invention is as follows:
  • the overcurrent protection component is close to the single-board power input interface and before the surge absorbing component, the overcurrent protection component is overcurrent when the subsequent circuit is short-circuited to prevent the short-circuit overcurrent of the single-board power supply circuit from igniting.
  • the two-way surge absorbing element is placed as close as possible to the overcurrent protection component to allow the lightning surge current to be vented to ground in the shortest path.
  • the anti-reverse diode is connected in series to the power supply circuit behind the parallel node of the surge absorbing element.
  • the reverse breakdown capability is greater than the DC operating voltage, so that the subsequent circuit can be prevented from being damaged.
  • the surge absorbing element is a two-way surge absorbing element.
  • the breakdown voltage exceeds the maximum working voltage of the DC power supply by more than 20%, and the overcurrent damage is not broken down regardless of whether the power supply is reversed or not.
  • the function modules in Figure 4 and Figure 5 illustrate:
  • the overcurrent protection component is an overcurrent fuse element such as a fuse.
  • the rated voltage should be equal to or greater than the maximum operating voltage of the DC power supply;
  • Rated current > According to the rated operating current of the board Operating ambient temperature
  • the derating design factor and the peak pulse current of VD 1 are determined. Slow-melting devices are generally available.
  • Bidirectional surge absorbing element such as bidirectional transient voltage absorbing diode
  • the circuit and the method of the present invention can effectively solve the problem of the protection of the single-board DC power input surge protection and the power supply reverse connection damage according to the application requirements of the device, thereby improving the reliability of the equipment and the board. Moreover, the circuit and method of the present invention avoids the reliability defects existing in the prior art, and is applicable to all communication devices and other electronic devices powered by a DC power source, and has high application value and wide application prospect.
  • Embodiment 1 Single board - 48V DC power input surge protection, see Figure 10.
  • Embodiment 2 Single board 24V DC power input surge protection, see Figure 11.
  • Embodiment 3 Single board 12V DC power input surge protection, see Figure 12.
  • the rated voltage should be equal to or greater than the maximum operating voltage of the DC power supply; Rated current 4 According to the rated operating current of the board Operating ambient temperature Derating design factor and the peak pulse current of VD1 are determined. Slow-melting devices are generally available.
  • VD1 - two-way shoe transient voltage absorbing diode The breakdown voltage exceeds about 20% of the maximum operating voltage of the DC power supply.
  • VD1 can select a TVS with a breakdown voltage of 68V.
  • VD1 can select a TVS with a breakdown voltage of 36V.
  • VD1 can be selected as a breakdown voltage.
  • the TVS is 18V; the peak pulse current is determined according to the surge level.
  • VD2 - rectifier diode The reverse breakdown voltage exceeds the maximum operating voltage of the DC power supply voltage by about 100%; the forward operating current exceeds the rated operating current of the board by about 100%.

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  • Emergency Protection Circuit Devices (AREA)

Abstract

A protection circuit for single-board DC power source interface comprises a first input terminal (11) for inputting DC current, a second input terminal (12) for outputting DC current, a surge absorbing unit (21) for preventing surge connected between a first node connected to the input terminal for the sequential circuit and a second node, a reverse connection preventing diode (22) to prevent the power source from damage by reverse connection connected between the second node and the output terminal for the sequential circuit, in which the positive pole is connected to the output terminal for the sequential circuit and the negative pole is connected to the second node, and a over-current preventing unit (30) connected between the second input terminal (12) and the second node or between the first input terminal (11) and the first node. When the over-current preventing unit (30) is connected between the second input terminal (12) and the second node, the first node is connected to the first input terminal. When the over-current preventing unit (30) is connected between the first input terminal (11) and the first node, the second node is connected to the second input terminal.

Description

单板直流电源端口的保护电路 技术领域 本发明涉及直流电源端口的保护，尤其涉及一种单板直流电源端口的保护 电路。 背景技术 因雷击、 电力系统的过电压等原因， 即使经过电源设备的前级过电压过电 流保护， 也可能使直流供电的通讯设备在直流端口遭受一定能量的浪涌冲击。 根据过电压过电流分级保护的原则， 单板直流电源端口需要设置相应能量级别 的浪涌吸收电路。 同时直流电源端口为了防止使用者接线时将正负极性接反， 出于安全考虑设置防反接保护也是一种需要。 目前，单板级直流电源端口的防浪涌和防电源反接损坏的保护的主要应用 电路有如下二种方式。 下面以 -48V直流电源输入保护电路来说明。  TECHNICAL FIELD The present invention relates to protection of a DC power port, and more particularly to a protection circuit for a single-board DC power port. Background Art Due to lightning strikes, overvoltage of a power system, etc., even if the overcurrent overcurrent protection of the power supply device is passed, the DC power supply communication device may be subjected to a surge of a certain amount of energy at the DC port. According to the principle of over-voltage over-current grading protection, the single-board DC power port needs to set the surge absorbing circuit of the corresponding energy level. At the same time, in order to prevent the user from reversing the positive and negative polarity of the DC power port, it is also necessary to set the anti-reverse protection for safety reasons. At present, the main application circuits for protection against surge and reverse power supply damage of single-board DC power ports are as follows. The following is a description of the -48V DC power input protection circuit.
1、 图 1为由保险管 FU1和单向硅瞬变电压吸收二极管（ Transient Voltage Suppressor, TVS ) D1组成的 -48V直流电源输入保护电路。 D1用于浪涌吸收， 且在直流电源接反时 D1正向导通， 过电流致使 FU1动作保护。 此电路存在的问题是直流电源接反后 FU1动作产生热冲击， FU1需要恢 复或更换， 增加维护成本。 而且直流电源接反后瞬间对后继的电源输入电路造 成冲击影响。 1. Figure 1 shows a -48V DC power input protection circuit consisting of fuse FU1 and Transient Voltage Suppressor (TVS) D1. D1 is used for surge absorption, and when the DC power supply is reversed, D1 is forward-conducting, and the overcurrent causes FU1 to operate. The problem with this circuit is that the FU1 action generates a thermal shock after the DC power supply is connected, and the FU1 needs to be restored or replaced, increasing the maintenance cost. Moreover, the DC power supply is reversed and immediately impacts the subsequent power input circuit.
2、图 2为由保险管 FU1、整流二极管 D2和硅瞬变电压吸收二极管（ TVS ) D1组成的 -48V直流电源输入保护电路。 D2用于直流电源防反接， D1用于浪 涌吸收。 此电路存在的问题是防反二极管在 TVS之前， 防反二极管不利于浪涌泄 放。 因为， 若防反二极管反向击穿电压过高， 则浪涌电流可能通过电源后继泄 放对设备造成冲击损坏； 若防反二极管反向击穿电压较低， 则浪涌要先后击穿 TVS管和防反二极管再泄放到大地，通道不畅且防反二极管也可能发生过流损 坏。 因此， 需要一种新的保护电路方案， 能够克服上述缺陷。 发明内容 本发明的主要目的在于提供一种单板直流电源端口的保护电路，用于克服 现有技术中存在器件和后继电路受到冲击影响的缺点， 解决现有技术中存在的 可靠性方面缺陷， 全面合理的解决单板级直流电源端口防浪涌和防电源反接损 坏问题。 为了实现上述目的，本发明提供了一种单板直流电源端口的保护电路。该 保护电路包括： 第一输入端， 用于流入直流电流； 第二输入端， 用于流出直流 电流； 浪涌吸收单元， 连接在第一节点和第二节点之间， 用于防浪涌， 其中， 第一节点连接至后续电路的电流流入端； 防反二极管， 连接在第二节点和后续 电路的电流流出端之间， 用于防电源反接损坏， 防反二极管的正极连接至后续 电路的电流流出端， 防反二极管的负极连接至第二节点； 以及过流保护单元， 连接在第二输入端和第二节点之间， 或者连接在第一输入端和第一节点之间， 其中， 当过流保护单元连接在第二输入端和第二节点之间时， 第一节点连接至 第一输入端， 当过流保护单元连接在第一输入端和第一节点之间时， 第二节点 连接至第二输入端。 浪涌吸收单元可以为双向浪涌吸收元件。可选地，浪涌吸收单元为双向石圭 瞬变电压吸收二极管或压敏电阻。 进一步地，浪涌吸收单元的击穿电压高于直流电源的最高工作电压，峰值 月 冲电流基于浪涌水平来确定。 防反二极管可以为整流二极管。 进一步地， 防反二极管的反向击穿电压高于直流电源的最高工作电压，正 向工作电流超过单板额定工作电流。 过流保护单元可以为过流熔断元件。可选地，过流保护单元为保险丝或保 险管。 进一步地， 过流保护单元的额定电压大于等于直流电源的最高工作电压， 额定电流根据单板的额定工作电流、 工作环境温度、 降额设计系数和浪涌吸收 单元的峰值脉冲电流来确定。 优选地， 过流保护单元为慢熔器件。 可选地，直流电源为正接地的直流电源，过流保护单元连接在第二输入端 和第二节点之间。 直流电源的电压可以为 - 48V。 可选地，直流电源为负接地的直流电源，过流保护单元连接在第一输入端 和第一节点之间。 直流电源的电压可以为 24V或 12V。 通过上述技术方案，本发明提高了单板级直流电源端口浪涌防护和电源反 接损坏防护的可靠性。 附图说明 此处所说明的附图用来提供对本发明的进一步理解， 构成本申请的一部 分， 本发明的示意性实施例及其说明用于解释本发明， 并不构成对本发明的不 当限定。 在附图中： 图 1是现有技术中直流电源输入保护电路方式 1的电路图； 图 2是现有技术中直流电源输入保护电路方式 2的电路图； 图 3是根据本发明的单板直流电源端口的保护电路的电路图； 图 4是根据本发明实施例的正接地的直流电源浪涌保护电路的功能框图； 图 5是根据本发明实施例的负接地的直流电源浪涌保护电路的功能框图； 图 6是根据本发明实施例的直流电源输入浪涌波形图； 图 7是根据本发明实施例的防反二极管前的残余浪涌波形图； 图 8是根据本发明实施例的直流电源输入 -48V接反时在防反二极管前的 波形图； 图 9是 >据本发明实施例的直流电源输入 -48V接反时在防反二极管后的 波形图； 图 10是根据本发明实施例的 -48V直流电源浪涌保护电路的电路图； 图 11是根据本发明实施例的 24V直流电源浪涌保护电路的电路图； 以及 图 12是根据本发明实施例的 12V直流电源浪涌保护电路的电路图。 具体实施方式 下面将参考附图详细说明本发明。 参照图 3 , 根据本发明的单板直流电源端口的保护电路包括： 第一输入端 11 , 用于流入直流电流； 第二输入端 12 , 用于流出直流电流； 浪涌吸收单元 21 , 连接在第一节点和第二节点之间， 用于防浪涌， 其中， 第一节点连接至后 续电路的电流流入端； 防反二极管 22, 连接在第二节点和后续电路的电流流出 端之间， 用于防电源反接损坏， 防反二极管 22 的正极连接至后续电路的电流 流出端， 防反二极管 22的负极连接至第二节点； 以及过流保护单元 30 , 连接 在第二输入端 12和第二节点之间，或者连接在第一输入端 11和第一节点之间， 其中， 当过流保护单元 30连接在第二输入端 12和第二节点之间时， 第一节点 连接至第一输入端 11 , 当过流保护单元 30连接在第一输入端 11和第一节点之 间时， 第二节点连接至第二输入端 12。 浪涌吸收单元 21 可以为双向浪涌吸收元件。 可选地， 浪涌吸收单元 21 为双向桂瞬变电压吸收二极管或压敏电阻。 进一步地， 浪涌吸收单元 21的击穿电压高于直流电源的最高工作电压， 峰值脉冲电流基于浪涌水平来确定。 防反二极管 22可以为整流二极管。 进一步地，防反二极管 22的反向击穿电压高于直流电源的最高工作电压， 正向工作电流超过单板额定工作电流。 过流保护单元 30可以为过流熔断元件。 可选地， 过流保护单元 30为保 险丝或保险管。 进一步地， 过流保护单元 30的额定电压大于等于直流电源的最高工作电 压， 额定电流 居单板的额定工作电流、 工作环境温度、 降额设计系数和浪涌 吸收单元 21的峰值 冲电流来确定。 优选地， 过流保护单元 30为慢熔器件。 可选地， 直流电源为正接地的直流电源， 过流保护单元 30连接在第二输 入端 12和第二节点之间。 直流电源的电压可以为 - 48V。 可选地， 直流电源为负接地的直流电源， 过流保护单元 30连接在第一输 入端 11和第一节点之间。 直流电源的电压可以为 24V或 12V。 本发明涉及到用于直流电源供电的通讯设备，或其它用这些直流电源的电 子设备的单板级直流电源端口的防浪涌和防电源反接损坏的保护。 不仅适用于 通过分散供电设备背板引入电源的插拔式单板， 也适用于外接电源引线的台式 设备单板。 图 4为正接地的直流电源 （如 -48V )浪涌保护电路的功能框图。 图 5为 负接地的直流电源 （如 24V )浪涌保护电路的功能框图。 参见图 4和图 5 , 根 据本发明的技术方案如下： 2. Figure 2 shows a -48V DC power input protection circuit consisting of fuse FU1, rectifier diode D2 and silicon transient voltage absorbing diode (TVS) D1. D2 is used for anti-reverse connection of DC power supply, and D1 is used for surge absorption. The problem with this circuit is that the anti-reverse diode is not conducive to surge bleed before the TVS. Because, if the reverse breakdown voltage of the anti-reverse diode is too high, the surge current may cause impact damage to the device through the subsequent discharge of the power supply; if the reverse breakdown voltage of the anti-reverse diode is low, the surge must break through the TVS one after another. The tube and the anti-reverse diode are vented to the earth again, the channel is not smooth, and the anti-reverse diode may also have excessive flow loss. Bad. Therefore, a new protection circuit scheme is needed to overcome the above drawbacks. SUMMARY OF THE INVENTION A primary object of the present invention is to provide a protection circuit for a DC power port of a single board, which overcomes the shortcomings of the prior art in which the device and the subsequent circuit are affected by the impact, and solves the reliability defects existing in the prior art. Comprehensive and reasonable solution to the problem of anti-surge and reverse power supply damage of the board-level DC power port. In order to achieve the above object, the present invention provides a protection circuit for a single-board DC power port. The protection circuit comprises: a first input for flowing a direct current; a second input for flowing a direct current; and a surge absorbing unit connected between the first node and the second node for preventing surges, Wherein, the first node is connected to the current inflow end of the subsequent circuit; the anti-reverse diode is connected between the current outlet end of the second node and the subsequent circuit for preventing reverse connection damage of the power source, and the positive pole of the anti-reverse diode is connected to the subsequent circuit a current outflow end, the negative pole of the anti-reverse diode is connected to the second node; and an overcurrent protection unit connected between the second input end and the second node, or connected between the first input end and the first node, wherein When the overcurrent protection unit is connected between the second input terminal and the second node, the first node is connected to the first input end, and when the overcurrent protection unit is connected between the first input end and the first node, The two nodes are connected to the second input. The surge absorbing unit can be a two-way surge absorbing element. Optionally, the surge absorbing unit is a bidirectional stone transient voltage absorbing diode or varistor. Further, the breakdown voltage of the surge absorbing unit is higher than the highest operating voltage of the DC power source, and the peak monthly current is determined based on the surge level. The anti-reverse diode can be a rectifier diode. Further, the reverse breakdown voltage of the anti-reverse diode is higher than the highest operating voltage of the DC power supply, and the forward operating current exceeds the rated operating current of the single board. The overcurrent protection unit can be an overcurrent fuse element. Optionally, the overcurrent protection unit is a fuse or a fuse. Further, the rated voltage of the overcurrent protection unit is greater than or equal to the maximum operating voltage of the DC power source, and the rated current is determined according to the rated operating current of the board, the working environment temperature, the derating design coefficient, and the peak pulse current of the surge absorbing unit. Preferably, the overcurrent protection unit is a slow melt device. Optionally, the DC power source is a DC power source that is grounded, and the overcurrent protection unit is connected between the second input end and the second node. The DC power supply can be -48V. Optionally, the DC power source is a negatively grounded DC power source, and the overcurrent protection unit is connected between the first input end and the first node. The DC power supply can be 24V or 12V. Through the above technical solution, the invention improves the reliability of the surge protection of the single-board DC power port and the protection against the reverse connection of the power supply. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are set to illustrate,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 1 is a circuit diagram of a DC power input protection circuit 1 in the prior art; FIG. 2 is a circuit diagram of a DC power input protection circuit 2 in the prior art; FIG. 3 is a single-board DC power supply according to the present invention; FIG. 4 is a functional block diagram of a DC power surge protection circuit that is grounded in accordance with an embodiment of the present invention; FIG. 5 is a functional block diagram of a DC power surge protection circuit with a negative ground according to an embodiment of the present invention. 6 is a DC power input surge waveform diagram according to an embodiment of the present invention; FIG. 7 is a residual surge waveform diagram before an anti-reverse diode according to an embodiment of the present invention; FIG. 8 is a waveform diagram of the DC power supply input -48V connected in front of the anti-reverse diode according to an embodiment of the present invention; FIG. 9 is a diagram of the DC power supply input -48V reversed after the anti-reverse diode according to the embodiment of the present invention; FIG. 10 is a circuit diagram of a -48 V DC power surge protection circuit according to an embodiment of the present invention; FIG. 11 is a circuit diagram of a 24 V DC power surge protection circuit according to an embodiment of the present invention; and FIG. 12 is an implementation according to the present invention. A circuit diagram of a 12V DC power surge protection circuit. DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to the accompanying drawings. Referring to FIG. 3, a protection circuit for a single-board DC power port according to the present invention includes: a first input terminal 11 for flowing a direct current; a second input terminal 12 for flowing a direct current; and a surge absorbing unit 21 connected to Between the first node and the second node, for preventing surge, wherein the first node is connected to the current inflow end of the subsequent circuit; the anti-reverse diode 22 is connected between the current outflow end of the second node and the subsequent circuit, For preventing reverse connection damage, the anode of the anti-reverse diode 22 is connected to the current outflow terminal of the subsequent circuit, the cathode of the anti-reverse diode 22 is connected to the second node; and the overcurrent protection unit 30 is connected to the second input terminal 12 and Between the second node, or connected between the first input end 11 and the first node, wherein when the overcurrent protection unit 30 is connected between the second input end 12 and the second node, the first node is connected to the first node An input terminal 11 is connected to the second input terminal 12 when the overcurrent protection unit 30 is connected between the first input terminal 11 and the first node. The surge absorbing unit 21 may be a two-way surge absorbing element. Optionally, the surge absorbing unit 21 is a bidirectional transient voltage absorbing diode or a varistor. Further, the breakdown voltage of the surge absorbing unit 21 is higher than the highest operating voltage of the DC power source, and the peak pulse current is determined based on the surge level. The anti-reverse diode 22 can be a rectifier diode. Further, the reverse breakdown voltage of the anti-reverse diode 22 is higher than the highest operating voltage of the DC power supply, and the forward operating current exceeds the rated operating current of the single board. The overcurrent protection unit 30 can be an overcurrent fuse element. Optionally, the overcurrent protection unit 30 is a fuse or a fuse. Further, the rated voltage of the overcurrent protection unit 30 is greater than or equal to the highest operating voltage of the DC power source, and the rated current is determined by the rated operating current of the board, the working environment temperature, the derating design coefficient, and the peak current of the surge absorbing unit 21. . Preferably, the overcurrent protection unit 30 is a slow melting device. Optionally, the DC power source is a DC power source that is grounded, and the overcurrent protection unit 30 is connected between the second input terminal 12 and the second node. The DC power supply can be -48V. Optionally, the DC power source is a negatively grounded DC power source, and the overcurrent protection unit 30 is connected between the first input terminal 11 and the first node. The DC power supply can be 24V or 12V. The invention relates to a protection against surge and reverse power supply damage of a single-board DC power port of a communication device for DC power supply or other electronic devices using these DC power sources. It is applicable not only to plug-in boards that introduce power through the backplane of the power supply unit, but also to desktop boards that have external power leads. Figure 4 is a functional block diagram of a surge protection circuit for a DC power supply (such as -48V) that is grounded. Figure 5 is a functional block diagram of a negative-grounded DC power supply (such as 24V) surge protection circuit. Referring to FIG. 4 and FIG. 5, the technical solution according to the present invention is as follows:
( 1 )过流保护元件靠近单板电源输入接口且在浪涌吸收元件之前， 过流 保护元件在后继电路短路时过流动作以防止单板电源电路短路过流着火。 (1) The overcurrent protection component is close to the single-board power input interface and before the surge absorbing component, the overcurrent protection component is overcurrent when the subsequent circuit is short-circuited to prevent the short-circuit overcurrent of the single-board power supply circuit from igniting.
( 2 )双向浪涌吸收元件尽量靠近过流保护元件， 以使雷击浪涌电流以最 短的路径泄放到地。 (2) The two-way surge absorbing element is placed as close as possible to the overcurrent protection component to allow the lightning surge current to be vented to ground in the shortest path.
( 3 ) 防反二极管串联在浪涌吸收元件并联节点后面的电源回路上。 当直 流电源正负接反时， 由于其反向击穿能力大于直流工作电压， 所以可以防止后 继电路损坏。 (3) The anti-reverse diode is connected in series to the power supply circuit behind the parallel node of the surge absorbing element. When straight When the current source is negatively connected, the reverse breakdown capability is greater than the DC operating voltage, so that the subsequent circuit can be prevented from being damaged.
( 4 )浪涌吸收元为双向的浪涌吸收元件， 击穿电压超过直流电源最高工 作电压 20%以上， 不论电源是否接反均不会击穿而过流损坏。 图 4和图 5中各功能模块说明： 过流保护元件 为保险管等过流熔断元件。额定电压应该等于或大 于直流电源最高工作电压； 额定电流 >据单板的额定工作电流 工作环境温度 降额设计系数和 VD 1的峰值脉冲电流确定。 一般可选慢熔的器件。 (4) The surge absorbing element is a two-way surge absorbing element. The breakdown voltage exceeds the maximum working voltage of the DC power supply by more than 20%, and the overcurrent damage is not broken down regardless of whether the power supply is reversed or not. The function modules in Figure 4 and Figure 5 illustrate: The overcurrent protection component is an overcurrent fuse element such as a fuse. The rated voltage should be equal to or greater than the maximum operating voltage of the DC power supply; Rated current > According to the rated operating current of the board Operating ambient temperature The derating design factor and the peak pulse current of VD 1 are determined. Slow-melting devices are generally available.
、浪涌吸收元件 双向的浪涌吸收元件， 如双向娃瞬变电压吸收二极管Surge absorbing element Bidirectional surge absorbing element, such as bidirectional transient voltage absorbing diode
( TVS ) 压敏电阻等。 击穿电压超过直流电源最高工作电压 20%左右； 峰值 脉冲电流根据浪涌水平确定。 防反二极管——整流二极管。反向击穿电压超过直流电源电压最高工作电 压 100%左右； 正向工作电流超过单板额定工作电流 100%左右。 以下面试猃数据对本发明的效果给予说明。 a )按 IEC61000-4-5标准在单板直流电源输入端口进行线-线 IkV浪涌试 驗。 图 6为按 IEC61000-4-5标准规定的直流电源输入浪涌试验波形。 图 Ί表示的是采用本发明提供的电路后，经过浪涌吸收元件后防反二极管 前测得的残余浪涌波形。 结果显示残余浪涌波形峰值电压只有一百多伏， 而且 波形时间缩短， 能量大幅度降低， 不会对后继电路造成危害性冲击。 b )直流电源接反时防反二极管的作用。 以 -48V直流电源输入的单板来说 明。 图 8为直流电源输入 -48V接反时， 单板输入的电压波形。 图 9表示的是采用本发明提供的电路后， 在直流电源输入 -48V接反时， 防反二极管后的电压波形， 此时防反二极管后继电路电压为 0V, 后继电路得 到保护。 显然，本发明电路和方法根据设备应用需求能够有效的解决单板级直流电 源输入浪涌防护和电源反接损坏防护的问题， 从而提高设备及单板工作可靠 性。 而且， 本发明电路及方法避免了现有技术中存在的可靠性方面缺陷， 适用 于所有釆用直流电源供电的通讯设备和其它电子设备， 具有较高的应用价值和 广泛的应用前景。 实施例 1 : 单板 -48V直流电源输入浪涌保护， 参见图 10。 实施例 2: 单板 24V直流电源输入浪涌保护， 参见图 11。 实施例 3: 单板 12V直流电源输入浪涌保护， 参见图 12。 图 10、 图 11、 图 12中器件参数选择说明: (TVS) Varistor, etc. The breakdown voltage exceeds about 20% of the maximum operating voltage of the DC power supply; the peak pulse current is determined according to the surge level. Anti-reverse diode - rectifier diode. The reverse breakdown voltage exceeds 100% of the maximum operating voltage of the DC power supply voltage; the forward operating current exceeds 100% of the rated operating current of the board. The following interview data will explain the effects of the present invention. a) Line-to-line IkV surge test at the DC power input port of the board according to IEC61000-4-5. Figure 6 shows the waveform of the DC power input surge test according to IEC61000-4-5. Figure Ί shows the residual surge waveform measured before the anti-reverse diode after the surge absorbing element is applied by the circuit provided by the present invention. The result shows that the peak voltage of the residual surge waveform is only over one hundred volts, and the waveform time is shortened, and the energy is greatly reduced, which will not cause harmful impact on the subsequent circuit. b) The function of the anti-reverse diode when the DC power supply is connected. The board is input with a -48V DC power supply. Figure 8 shows the voltage waveform input by the board when the DC power input -48V is connected. Figure 9 shows the voltage waveform after the anti-reverse diode is applied to the DC power supply input -48V after the circuit provided by the present invention is used. At this time, the anti-reverse diode subsequent circuit voltage is 0V, and the subsequent circuit is protected. Obviously, the circuit and the method of the present invention can effectively solve the problem of the protection of the single-board DC power input surge protection and the power supply reverse connection damage according to the application requirements of the device, thereby improving the reliability of the equipment and the board. Moreover, the circuit and method of the present invention avoids the reliability defects existing in the prior art, and is applicable to all communication devices and other electronic devices powered by a DC power source, and has high application value and wide application prospect. Embodiment 1: Single board - 48V DC power input surge protection, see Figure 10. Embodiment 2: Single board 24V DC power input surge protection, see Figure 11. Embodiment 3: Single board 12V DC power input surge protection, see Figure 12. Figure 10, Figure 11, Figure 12 device parameter selection instructions:
FU1——保险丝。 额定电压应该等于或大于直流电源最高工作电压； 额定 电流 4 据单板的额定工作电流 工作环境温度 降额设计系数和 VD1 的峰值 脉冲电流确定。 一般可选慢熔的器件。 FU1 - fuse. The rated voltage should be equal to or greater than the maximum operating voltage of the DC power supply; Rated current 4 According to the rated operating current of the board Operating ambient temperature Derating design factor and the peak pulse current of VD1 are determined. Slow-melting devices are generally available.
VD1——双向鞋瞬变电压吸收二极管 （TVS )。 击穿电压超过直流电源最 高工作电压 20%左右，图 10中 VD1可选击穿电压为 68V的 TVS,图 11中 VD1 可选击穿电压为 36V的 TVS, 图 12中 VD1可选击穿电压为 18V的 TVS; 峰 值脉冲电流根据浪涌水平确定。 VD1 - two-way shoe transient voltage absorbing diode (TVS). The breakdown voltage exceeds about 20% of the maximum operating voltage of the DC power supply. In Figure 10, VD1 can select a TVS with a breakdown voltage of 68V. In Figure 11, VD1 can select a TVS with a breakdown voltage of 36V. In Figure 12, VD1 can be selected as a breakdown voltage. The TVS is 18V; the peak pulse current is determined according to the surge level.
VD2——整流二极管。 反向击穿电压超过直流电源电压最高工作电压 100%左右； 正向工作电流超过单板额定工作电流 100%左右。 以上所述仅为本发明的优选实施例而已，并不用于限制本发明，对于本领 域的技术人员来说， 本发明可以有各种更改和变化。 凡在本发明的精神和原则 之内， 所作的任何修改、 等同替换、 改进等， 均应包含在本发明的保护范围之 内。 VD2 - rectifier diode. The reverse breakdown voltage exceeds the maximum operating voltage of the DC power supply voltage by about 100%; the forward operating current exceeds the rated operating current of the board by about 100%. The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention, and various modifications and changes can be made to the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present invention are intended to be included within the scope of the present invention.

Claims

权 利 要 求 书 Claim
1. 一种单板直流电源端口的保护电路， 其特征在于， 包括：  A protection circuit for a DC power port of a single board, comprising:
第一输入端， 用于流入直流电流；  a first input terminal for flowing a direct current;
第二输入端， 用于流出直流电流；  a second input terminal for discharging a direct current;
浪涌吸收单元， 连接在第一节点和第二节点之间， 用于防浪涌， 其 中， 所述第一节点连接至后续电路的电流流入端；  a surge absorbing unit, connected between the first node and the second node, for preventing surge, wherein the first node is connected to a current inflow end of a subsequent circuit;
防反二极管， 连接在所述第二节点和后续电路的电流流出端之间， 用于防电源反接损坏， 所述防反二极管的正极连接至所述后续电路的电 流流出端， 所述防反二极管的负极连接至所述第二节点； 以及  a anti-reverse diode connected between the current outflow end of the second node and the subsequent circuit for preventing reverse connection damage of the power source, the anode of the anti-reverse diode being connected to the current outflow end of the subsequent circuit, the a cathode of the reverse diode is coupled to the second node;
过流保护单元， 连接在所述第二输入端和所述第二节点之间， 或者 连接在所述第一输入端和所述第一节点之间， 其中， 当所述过流保护单 元连接在所述第二输入端和所述第二节点之间时， 所述第一节点连接至 所述第一输入端， 当所述过流保护单元连接在所述第一输入端和所述第 一节点之间时， 所述第二节点连接至所述第二输入端。  An overcurrent protection unit, connected between the second input end and the second node, or connected between the first input end and the first node, wherein when the overcurrent protection unit is connected The first node is connected to the first input when the second input end is connected to the second node, and when the overcurrent protection unit is connected to the first input end and the first The second node is connected to the second input when between a node.
2. 根据权利要求 1所述的保护电路， 其特征在于， 所述浪涌吸收单元为双 向浪涌吸收元件。 2. The protection circuit according to claim 1, wherein the surge absorbing unit is a bidirectional surge absorbing element.
3. 根据权利要求 2所述的保护电路， 其特征在于， 所述浪涌吸收单元为双 向硅瞬变电压吸收二极管或压敏电阻。 3. The protection circuit according to claim 2, wherein the surge absorbing unit is a bidirectional silicon transient voltage absorbing diode or a varistor.
4. 根据权利要求 1至 3中任一项所述的保护电路， 其特征在于， 所述浪涌 吸收单元的击穿电压高于直流电源的最高工作电压， 峰值^ 中电流基于 -浪涌水平来确定。 The protection circuit according to any one of claims 1 to 3, wherein a breakdown voltage of the surge absorbing unit is higher than a maximum operating voltage of a direct current power source, and a peak current is based on a surge level to make sure.
5. 根据权利要求 1所述的保护电路， 其特征在于， 所述防反二极管为整流 二极管。 5. The protection circuit according to claim 1, wherein the anti-reverse diode is a rectifying diode.
6. 根据权利要求 1或 5所述的保护电路， 其特征在于， 所述防反二极管的 反向击穿电压高于直流电源的最高工作电压， 正向工作电流超过单板额 δ 定工作电流。 The protection circuit according to claim 1 or 5, wherein the reverse breakdown voltage of the anti-reverse diode is higher than the maximum operating voltage of the DC power supply, and the forward operating current exceeds the board δ Set the working current.
7. 根据权利要求 1所述的保护电路， 其特征在于， 所述过流保护单元为过 流熔断元件。 7. The protection circuit according to claim 1, wherein the overcurrent protection unit is an overcurrent fuse element.
8. 根据权利要求 7所述的保护电路， 其特征在于， 所述过流保护单元为保 险丝或保险管。 8. The protection circuit according to claim 7, wherein the overcurrent protection unit is a fuse or a fuse.
9. 根据权利要求 1、 7和 8中任一项所述的保护电路， 其特征在于， 所述过 流保护单元的额定电压大于等于直流电源的最高工作电压， 额定电流冲艮 据单板的额定工作电流、 工作环境温度、 降额设计系数和所述浪涌吸收 单元的峰值脉冲电流来确定。 The protection circuit according to any one of claims 1 to 7, wherein the rated voltage of the overcurrent protection unit is greater than or equal to a maximum operating voltage of the DC power source, and the rated current is flushed according to the board. The rated operating current, the operating ambient temperature, the derating design factor, and the peak pulse current of the surge absorbing unit are determined.
10. 根据权利要求 1、 7和 8中任一项所述的保护电路， 其特征在于， 所述过 流保护单元为†曼熔器件。 The protection circuit according to any one of claims 1, 7 and 8, wherein the overcurrent protection unit is a †曼熔 device.
11. 根据权利要求 1所述的保护电路， 其特征在于， 所述直流电源为正接地 的直流电源， 所述过流保护单元连接在所述第二输入端和所述第二节点 之间。 The protection circuit according to claim 1, wherein the DC power source is a DC power source that is grounded, and the overcurrent protection unit is connected between the second input terminal and the second node.
12. 根据权利要求 11所述的保护电路， 其特征在于， 所述直流电源的电压为 - 48V。 12. The protection circuit according to claim 11, wherein the voltage of the direct current power source is -48V.
13. 根据权利要求 1所述的保护电路， 其特征在于， 所述直流电源为负接地 的直流电源， 所述过流保护单元连接在所述第一输入端和所述第一节点 之间。 根据权利要求 13所述的保护电路， 其特征在于， 所述直流电源的电压为 24V或 12V。 The protection circuit according to claim 1, wherein the DC power source is a negatively grounded DC power source, and the overcurrent protection unit is connected between the first input end and the first node. The protection circuit according to claim 13, wherein the voltage of the direct current power source is 24V or 12V.
PCT/CN2006/003261 2006-12-04 2006-12-04 Protection circuit for single-board dc power source interface WO2008067686A1 (en)

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Application Number Priority Date Filing Date Title
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4099216A (en) * 1976-11-12 1978-07-04 Westinghouse Electric Corp. Fuseless intrinsic safety barrier
US4860151A (en) * 1987-09-26 1989-08-22 Measurement Technology Limited Electrical safety barriers
CN2146802Y (en) * 1993-03-22 1993-11-17 杨季民 Multi-functional fuse box
CN2454965Y (en) * 2000-11-01 2001-10-17 何晶晶 Thunder-proof telephone service-box

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4099216A (en) * 1976-11-12 1978-07-04 Westinghouse Electric Corp. Fuseless intrinsic safety barrier
US4860151A (en) * 1987-09-26 1989-08-22 Measurement Technology Limited Electrical safety barriers
CN2146802Y (en) * 1993-03-22 1993-11-17 杨季民 Multi-functional fuse box
CN2454965Y (en) * 2000-11-01 2001-10-17 何晶晶 Thunder-proof telephone service-box

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