CN202384752U - Switching power supply overcurrent protection circuit - Google Patents

Switching power supply overcurrent protection circuit Download PDF

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Publication number
CN202384752U
CN202384752U CN2011205251440U CN201120525144U CN202384752U CN 202384752 U CN202384752 U CN 202384752U CN 2011205251440 U CN2011205251440 U CN 2011205251440U CN 201120525144 U CN201120525144 U CN 201120525144U CN 202384752 U CN202384752 U CN 202384752U
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CN
China
Prior art keywords
mentioned
diode
power supply
switching power
capacitor
Prior art date
Legal status (The legal status 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 status listed.)
Expired - Fee Related
Application number
CN2011205251440U
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Chinese (zh)
Inventor
吴华夏
刘劲松
孟庆贤
刘学
姜树广
胡俊鹏
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Anhui East China Institute of Optoelectronic Technology
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Anhui East China Institute of Optoelectronic Technology
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Priority to CN2011205251440U priority Critical patent/CN202384752U/en
Application granted granted Critical
Publication of CN202384752U publication Critical patent/CN202384752U/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

The utility model discloses a switching power supply overcurrent protection circuit, which comprises a first diode, a second diode, a Zener diode, a transistor, a field effect transistor and a capacitor; the second diode is connected in series with the Zener diode, the cathodes of the second diode and the Zener diode are connected with each other, the anode of the Zener diode is connected with the base of the transistor, the anode of the second diode is connected with the anode of the first diode and the first end of the capacitor, the cathode of the first diode is connected with the drain of the field effect transistor, the second end of the capacitor is connected with the emitter of the transistor, the collector of the transistor is connected with the grid of the field effect transistor, and the source of the field effect transistor is connected with the emitter of the transistor and the second end of the capacitor. The switching power supply overcurrent protection circuit has the advantages that: the protection circuit can effectively detect the overcurrent of a power supply, and the sensitivity and the reliability are excellent.

Description

The Switching Power Supply current foldback circuit
Technical field
The utility model relates to a kind of current foldback circuit, is specifically related to a kind of Switching Power Supply current foldback circuit; Belong to electricity field.
Background technology
Application of switching power is extensive, can operating voltage be provided for various kinds of equipment.In its course of work, when the output of power supply surpasses nominal load or short circuit, can cause damage to power supply, make system's cisco unity malfunction.And current Switching Power Supply operating frequency is increasingly high, in order to improve the reliability of Switching Power Supply, must protective circuit reasonable in design, and the sensitivity of protective circuit and reliability are to the important role in safe operation of Switching Power Supply.
Traditional current foldback circuit utilizes instrument transformer to gather electric current; After the switching signal level of electric current-voltage is higher than fiducial value; The protection pin of importing PWM (Pulse Width Modulation, pulse-width modulation) chip is to turn-off vibration output or to cut off the mode of supplying power through relay and realize the Switching Power Supply overcurrent protection.But this mode exists that response speed is slow, slow movement, possibly have little time shortcomings such as action to the excessively rapid growth of short-circuit electric current; In addition, in the time of the over-current signal level also possibly occurring and raise, chip by output, electric current reduce, chip works on, continue one of overcurrent shakes and stop improper situation, thereby cause system works unstable, even might burn power device.Now still there is not a kind of current foldback circuit that can take into account sensitivity and reliability.
The utility model content
The purpose of the utility model is to overcome the deficiency that exists in the prior art, provides a kind of sensitivity and reliability good Switching Power Supply current foldback circuit.
In order to achieve the above object, the present invention adopts following technical scheme:
The Switching Power Supply current foldback circuit is characterized in that, comprising: first diode, second diode, voltage stabilizing didoe, triode, FET, capacitor; Above-mentioned second diode is connected with above-mentioned voltage stabilizing didoe; Their negative pole is connected; The positive pole of above-mentioned voltage stabilizing didoe is connected with the base stage of above-mentioned triode; The positive pole of above-mentioned second diode is connected with first end of the positive pole of above-mentioned first diode, above-mentioned capacitor, and the negative pole of above-mentioned first diode is connected with the drain electrode of FET, and second end of above-mentioned capacitor is connected with the emitter of above-mentioned triode; The collector electrode of above-mentioned triode is connected with the grid of above-mentioned FET, and the source electrode of above-mentioned FET is connected with second end of the emitter of above-mentioned triode, above-mentioned capacitor.
Aforesaid Switching Power Supply current foldback circuit is characterized in that, is in series with first resistance and second resistance between the collector electrode of above-mentioned second diode and above-mentioned triode.
Aforesaid Switching Power Supply current foldback circuit is characterized in that, draws circuit first incoming end that is used to insert power supply between above-mentioned first resistance and second resistance, and second end of above-mentioned capacitor is as circuit second incoming end that is used to insert power supply.
Aforesaid Switching Power Supply current foldback circuit is characterized in that, is connected with second biasing resistor between above-mentioned transistor emitter and the base stage.
Aforesaid Switching Power Supply current foldback circuit is characterized in that, is connected with first biasing resistor between the source electrode of above-mentioned FET and the grid.
Aforesaid Switching Power Supply current foldback circuit is characterized in that, first diode is a high pressure Ultrafast recovery type diode.
Aforesaid Switching Power Supply current foldback circuit is characterized in that, second diode is a low pressure Ultrafast recovery type Schottky tube.
The beneficial effect that the utility model reached is: a kind of protective circuit that can detect the power supply overcurrent effectively is provided, and sensitivity and reliability are good.
Description of drawings
Fig. 1 is the circuit diagram of a preferred embodiment of the utility model Switching Power Supply current foldback circuit.
The implication of Reference numeral among the figure:
D1: first diode; D2: second diode; D3: voltage stabilizing didoe; C1: capacitor; R1: first resistance; R2: second resistance; R3: first biasing resistor; R4: second biasing resistor; V1: FET; V2: triode; Ui: supply voltage.
Embodiment
Below in conjunction with accompanying drawing the utility model is further described.Present embodiment is an optimized technical scheme, only is used for more clearly explaining the technical scheme of the utility model, and does not limit the protection range of the utility model with this.
As shown in Figure 1, the described current foldback circuit of the utility model comprises: the first diode D1, the second diode D2, voltage stabilizing didoe D3, triode V2, FET V1, capacitor C1; The first diode D1 is a clamp diode, works to detect over-current signal; The second diode D2 connects with voltage stabilizing didoe D3, and their negative pole is connected, and the positive pole of voltage stabilizing didoe D3 is connected with the base stage of triode V2, plays the effect of stabilizing circuit voltage; The positive pole of the second diode D2 is connected with the positive pole of the first diode D1, first end of capacitor C1; The negative pole of the first diode D1 is connected with the drain electrode of FET V1; Second end of capacitor C1 is connected with the emitter of triode V2; The collector electrode of triode V2 is connected with the grid of FET V1, and the source electrode of FET V1 is connected with the emitter of triode V2, second end of capacitor C1.
As a kind of optimal way, also be in series with first resistance R 1 and second resistance R 2 between the collector electrode of the second diode D2 and triode V2, be used to realize the Current Regulation of circuit.Certainly, also can adopt the scheme of other resistance combination, regulate the electric current purpose to reach.
Also be connected with the first biasing resistor R3 between the source electrode of FET V1 and the grid, be connected with the second biasing resistor R4 between triode V2 emitter and the base stage, be used for adjusting the resistance of their biasing circuits, thereby realize the electric current adjustment.
Draw circuit first incoming end that is used to insert power supply between first resistance R 1 and second resistance R 2, second end of capacitor C1 is as circuit second incoming end that is used to insert power supply.
In order further to improve the sensitivity and the reliability of power supply current foldback circuit; Eliminate of the influence of the charge displacement electric current of voltage stabilizing didoe D3 junction capacitance formation to FET V1; The preferred high pressure Ultrafast recovery of first diode D1 type diode, the second diode D2 preferred lower pressure Ultrafast recovery type Schottky tube.
Supply voltage Ui makes the moment of FET V1 conducting, and capacitor C1 short circuit makes triode V2 remain off state and do not influence the conducting of FET V1.When field effect pipe V1 is in the normally state; Capacitor C1 charging voltage value can not make triode V2 conducting; The drain-source voltage of FET V1 is a low level, through the second diode D2 with A point current potential clamper low-potential state, so capacitor C1 stop the charging; This moment, the A point voltage was not enough to triode V2 is produced biasing, promptly can not influence the operating state of FET V1.
When field effect pipe V1 overcurrent, the voltage between its drain electrode and the source electrode rises rapidly, and the second diode D2 oppositely ends; The charging potential of capacitor C1 raises; Until voltage stabilizing didoe D3 reverse-conducting, triode V2 will be switched on this moment, and the grid potential of FET V1 is pulled down near 0V; Thereby make FET V1 reliable turn-off and end, limited overcurrent effectively.After overcurrent was eliminated, capacitor C1 can turn-off until triode V2 through first resistance R 1, second resistance R 2, triode V2 discharge, and circuit automatically restores to operating state.
The above only is the preferred implementation of the utility model; Should be understood that; For those skilled in the art; Under the prerequisite that does not break away from the utility model know-why, can also make some improvement and distortion, these improvement and distortion also should be regarded as the protection range of the utility model.

Claims (7)

1. the Switching Power Supply current foldback circuit is characterized in that, comprising: first diode, second diode, voltage stabilizing didoe, triode, FET, capacitor; Above-mentioned second diode is connected with above-mentioned voltage stabilizing didoe; Their negative pole is connected; The positive pole of above-mentioned voltage stabilizing didoe is connected with the base stage of above-mentioned triode; The positive pole of above-mentioned second diode is connected with first end of the positive pole of above-mentioned first diode, above-mentioned capacitor, and the negative pole of above-mentioned first diode is connected with the drain electrode of FET, and second end of above-mentioned capacitor is connected with the emitter of above-mentioned triode; The collector electrode of above-mentioned triode is connected with the grid of above-mentioned FET, and the source electrode of above-mentioned FET is connected with second end of the emitter of above-mentioned triode, above-mentioned capacitor.
2. Switching Power Supply current foldback circuit according to claim 1 is characterized in that, is in series with first resistance and second resistance between the collector electrode of above-mentioned second diode and above-mentioned triode.
3. Switching Power Supply current foldback circuit according to claim 2; It is characterized in that; Draw circuit first incoming end that is used to insert power supply between above-mentioned first resistance and second resistance, second end of above-mentioned capacitor is as circuit second incoming end that is used to insert power supply.
4. Switching Power Supply current foldback circuit according to claim 1 is characterized in that, is connected with second biasing resistor between above-mentioned transistor emitter and the base stage.
5. Switching Power Supply current foldback circuit according to claim 1 is characterized in that, is connected with first biasing resistor between the source electrode of above-mentioned FET and the grid.
6. according to any described Switching Power Supply current foldback circuit of claim 1 to 5, it is characterized in that first diode is a high pressure Ultrafast recovery type diode.
7. Switching Power Supply current foldback circuit according to claim 6 is characterized in that, above-mentioned second diode is a low pressure Ultrafast recovery type Schottky tube.
CN2011205251440U 2011-12-15 2011-12-15 Switching power supply overcurrent protection circuit Expired - Fee Related CN202384752U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2011205251440U CN202384752U (en) 2011-12-15 2011-12-15 Switching power supply overcurrent protection circuit

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2011205251440U CN202384752U (en) 2011-12-15 2011-12-15 Switching power supply overcurrent protection circuit

Publications (1)

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CN202384752U true CN202384752U (en) 2012-08-15

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103414163A (en) * 2013-08-26 2013-11-27 中国兵器工业集团第二一四研究所苏州研发中心 Direct-current power supply output overcurrent protection device
CN103762558A (en) * 2014-01-21 2014-04-30 北京航空航天大学 Recoverable power interface circuit resistant to single event latchup
CN106033880A (en) * 2015-03-09 2016-10-19 何曙光 Hiccup type protection circuits for DC power supply
CN106887825A (en) * 2017-03-03 2017-06-23 广东欧珀移动通信有限公司 Protective circuit of switch power source and voltage conversion apparatus
CN107104424A (en) * 2017-07-04 2017-08-29 上海沪工焊接集团股份有限公司 Realize wire-feed motor pulse current limliting and the circuit of stall overcurrent protection one by one
CN108258893A (en) * 2016-12-29 2018-07-06 亚瑞源科技(深圳)有限公司 Overcurrent protection circuit
CN112255451A (en) * 2020-12-21 2021-01-22 上海芯龙半导体技术股份有限公司南京分公司 Overcurrent detection circuit, overcurrent protection circuit and switching power supply
CN112345908A (en) * 2020-10-27 2021-02-09 郑州嘉晨电器有限公司 Current detection circuit of power switch tube

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103414163A (en) * 2013-08-26 2013-11-27 中国兵器工业集团第二一四研究所苏州研发中心 Direct-current power supply output overcurrent protection device
CN103762558A (en) * 2014-01-21 2014-04-30 北京航空航天大学 Recoverable power interface circuit resistant to single event latchup
CN106033880A (en) * 2015-03-09 2016-10-19 何曙光 Hiccup type protection circuits for DC power supply
CN109038504A (en) * 2015-03-09 2018-12-18 王振环 DC power supply hiccup formula protects circuit
CN109038503A (en) * 2015-03-09 2018-12-18 王振环 DC power supply hiccup formula protects circuit
CN106033880B (en) * 2015-03-09 2019-01-22 广东泓睿科技有限公司 DC power supply hiccup formula protects circuit
CN108258893A (en) * 2016-12-29 2018-07-06 亚瑞源科技(深圳)有限公司 Overcurrent protection circuit
CN108258893B (en) * 2016-12-29 2020-10-30 亚瑞源科技(深圳)有限公司 Overcurrent protection circuit
CN106887825A (en) * 2017-03-03 2017-06-23 广东欧珀移动通信有限公司 Protective circuit of switch power source and voltage conversion apparatus
CN107104424A (en) * 2017-07-04 2017-08-29 上海沪工焊接集团股份有限公司 Realize wire-feed motor pulse current limliting and the circuit of stall overcurrent protection one by one
CN112345908A (en) * 2020-10-27 2021-02-09 郑州嘉晨电器有限公司 Current detection circuit of power switch tube
CN112255451A (en) * 2020-12-21 2021-01-22 上海芯龙半导体技术股份有限公司南京分公司 Overcurrent detection circuit, overcurrent protection circuit and switching power supply

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C14 Grant of patent or utility model
GR01 Patent grant
CF01 Termination of patent right due to non-payment of annual fee

Granted publication date: 20120815

Termination date: 20151215

EXPY Termination of patent right or utility model