CN203339652U - Interface protection circuit - Google Patents
Interface protection circuit Download PDFInfo
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- CN203339652U CN203339652U CN2013204036075U CN201320403607U CN203339652U CN 203339652 U CN203339652 U CN 203339652U CN 2013204036075 U CN2013204036075 U CN 2013204036075U CN 201320403607 U CN201320403607 U CN 201320403607U CN 203339652 U CN203339652 U CN 203339652U
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- interface
- input interface
- sampling resistor
- power input
- pole end
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Abstract
The utility model relates to an interface protection circuit. The interface protection circuit comprises a power supply input interface and a power supply output interface. The power supply input interface is connected with an external DC power supply, the power supply output interface is connected to a load, and a switch circuit is connected between the power supply input interface and the power supply output interface. A positive pole end and a negative pole end of the power supply input interface are also successively connected with a sampling resistor R1, a sampling resistor R2 and a voltage stabilizing diode in series. An input end of the sampling resistor R1 is connected to the positive pole end of the power supply input interface, an output end of the sampling resistor R1 is connected with an input end of the sampling resistor R2, an output end of the sampling resistor R2 is connected with a negative pole end of the voltage stabilizing diode, a positive pole end of the voltage stabilizing diode is connected with the negative pole end of the power supply input interface, a control end of the switch circuit is connected with output end of the sampling resistor R1, and the switch circuit controls the load to be powered on or off according to voltages changes of the power supply input interface. The load is automatically stopped being powered on at a low cost when values of an input voltage and an input current are greater than set values; and, when the values of the input voltage and the input current are back to scopes of the set values, the load is automatically powered on again, and a reverse input circuit is automatically protected again.
Description
Technical field
The utility model relates to protective circuit, relates in particular to a kind of interface protective circuit.
Background technology
The USB interface of existing computer terminal adopts special-purpose protection chip to realize the protection of interface usually, and on consumer electronics product (as digital camera, Digital Video, MP3, MP4, mobile phone) or flash memory device (such as portable hard drive, flash disk etc.) USB interface, uses special-purpose its cost of protection chip to be undoubtedly huge.Equally, usining civil power, battery or PC etc. also tends to run into this kind of problem as the power access end mouth.
The utility model content
The purpose of this utility model is as overcoming the defect of prior art, and a kind of interface protective circuit is provided.
For achieving the above object, the utility model is by the following technical solutions: a kind of interface protective circuit, comprise power input interface and power output interface, power input interface is connected in external dc power, power output interface is connected in load, described power input interface and power output interface are connected with a switching circuit, described power input interface just, the negative pole end sampling resistor R1 that also connects successively, sampling resistor R2 and voltage stabilizing didoe, the input of sampling resistor R1 is connected in the power input interface positive terminal, the output of sampling resistor R1 connects the input of sampling resistor R2, the output of sampling resistor R2 connects the negative pole end of voltage stabilizing didoe, the positive terminal of voltage stabilizing didoe connects the power input interface negative pole end, the control end of described switching circuit is connected with the output of sampling resistor R1, described switching circuit is according to the change in voltage of power input interface and control load powers on or power down.
Described switching circuit comprises PMOS pipe and triode, the source electrode of described PMOS pipe is connected in the power input interface positive terminal, drain electrode is connected in the positive terminal of power output interface, the collector electrode that grid is connected in triode, and output, emitter that the base stage of triode is connected in sampling resistor R1 are connected in power input interface positive terminal, collector electrode and connect the negative pole end of power output interface via pull down resistor.
Described power input interface is positive and negative also connects a diode between extreme, and the negative pole end of described diode connects the power input interface positive terminal, and the positive terminal of diode connects the power input interface negative pole end.
Also be connected a resettable fuse between the positive terminal of described power input interface negative pole end and described diode.
Also be connected a resettable fuse between the negative pole end of described power input interface positive terminal and described diode.
Described sampling resistor R1 is adjustable resistance.
The utility model beneficial effect compared with prior art is: 1) realized at low cost when input voltage is greater than set point automatically stopping the power supply to load, voltage in getting back to the scope of set point the time, recovers the power supply to load automatically; 2) realized at low cost when input current is greater than set point automatically stopping the power supply to load, electric current in getting back to the scope of set point the time, recovers the power supply to load automatically; 3) realize cheaply the protection of reverse input circuit.
The accompanying drawing explanation
The circuit diagram that Fig. 1 is the utility model embodiment.
Embodiment
In order to more fully understand technology contents of the present utility model, below in conjunction with specific embodiment, the technical solution of the utility model is further introduced and explanation.
As shown in Figure 1, circuit diagram for the utility model embodiment, a kind of interface protective circuit, comprise power input interface and power output interface, power input interface is connected in external dc power, power output interface is connected in load RL, described power input interface and power output interface are connected with a switching circuit 1, described power input interface just, the negative pole end sampling resistor R1 that also connects successively, sampling resistor R2 and voltage stabilizing didoe DZ1, sampling resistor R1 input is connected in the power input interface positive terminal, sampling resistor R1 output connects the input of sampling resistor R2, the output of sampling resistor R2 connects the negative pole end of voltage stabilizing didoe DZ1, the positive terminal of voltage stabilizing didoe DZ1 connects the power input interface negative pole end, the control end of described switching circuit 1 is connected with sampling resistor R1 output, described switching circuit 1 is according to the change in voltage of power input interface and control load RL powers on or power down.
In the present embodiment, described switching circuit 1 comprises PMOS pipe Q2 and triode Q1, the source electrode of described PMOS pipe Q2 is connected in the collector electrode that positive terminal, grid that power input interface positive terminal, drain electrode be connected in power output interface are connected in triode Q1, and output, emitter that the base stage of triode Q1 is connected in sampling resistor R1 are connected in power input interface positive terminal, collector electrode and connect the negative pole end of power output interface via pull down resistor R3.
In foregoing circuit, described sampling resistor R1 can also be adjustable resistance, for regulating the setting protection voltage of this circuit.
Also connect a diode D1 between extreme described power input interface is positive and negative, the negative pole end of described diode D1 connects the power input interface positive terminal, and the positive terminal of diode D1 connects the power input interface negative pole end.
In addition, also be connected a resettable fuse FB1 between the positive terminal of described power input interface negative pole end and described diode D1.
In foregoing circuit, described resettable fuse FB1 can also be arranged between the negative pole end of described power input interface positive terminal and described diode D1.
Below protection philosophy of the present utility model is described:
Overvoltage protection: when the power input interface input voltage is greater than in the situation of set point, voltage stabilizing didoe DZ1 conducting, triode Q1 conducting, PMOS pipe Q2 cut-off, this protective circuit Non voltage output, load RL is protected.
Overcurrent protection: when the power input interface input current is greater than in the situation of set point, resettable fuse FB1 disconnects, and this circuit no current, protected load RL.
Reverse protection: when the positive and negative extreme input voltage of power input interface, by reversal connection, and input current is less than in the situation of set point, and diode D1 conducting forms loop, and large electric current passes through from diode D1, and load RL is protected.When the positive and negative extreme input voltage of power input interface, by reversal connection, and input current is greater than in the situation of set point, and resettable fuse FB1 disconnects, and this circuit no current, protected load RL.
Automatic recovery of power supply: when input current, voltage all are less than set point and the access of power input interface positive and negative electrode terminal voltage forward, diode D1 cut-off, voltage stabilizing didoe DZ1 cut-off, triode Q1 cut-off, PMOS pipe Q2 conducting, load RL normal operation.
This is practical can be used in any situation that needs interface protection, is not limited to usb type.Power input interface connects in the situations such as DC power supply, battery or PC all applicable.
The above only further illustrates technology contents of the present utility model with embodiment; so that the reader is easier to understand; but do not represent that execution mode of the present utility model only limits to this, any technology of doing according to the utility model is extended or recreation, all is subject to protection of the present utility model.
Claims (6)
1. an interface protective circuit, comprise power input interface and power output interface, power input interface is connected in external dc power, power output interface is connected in load, it is characterized in that, described power input interface and power output interface are connected with a switching circuit, described power input interface just, the negative pole end sampling resistor R1 that also connects successively, sampling resistor R2 and voltage stabilizing didoe, the input of sampling resistor R1 is connected in the power input interface positive terminal, the output of sampling resistor R1 connects the input of sampling resistor R2, the output of sampling resistor R2 connects the negative pole end of voltage stabilizing didoe, the positive terminal of voltage stabilizing didoe connects the power input interface negative pole end, the control end of described switching circuit is connected with the output of sampling resistor R1, described switching circuit is according to the change in voltage of power input interface and control load powers on or power down.
2. interface protective circuit according to claim 1; it is characterized in that; described switching circuit comprises PMOS pipe and triode; the source electrode of described PMOS pipe is connected in the power input interface positive terminal, drain electrode is connected in the positive terminal of power output interface, the collector electrode that grid is connected in triode, and output, emitter that the base stage of triode is connected in sampling resistor R1 are connected in power input interface positive terminal, collector electrode and connect the negative pole end of power output interface via pull down resistor.
3. according to the arbitrary described interface protective circuit of claim 1 or 2; it is characterized in that; described power input interface is positive and negative also connects a diode between extreme, and the negative pole end of described diode connects the power input interface positive terminal, and the positive terminal of diode connects the power input interface negative pole end.
4. interface protective circuit according to claim 3, is characterized in that, between the positive terminal of described power input interface negative pole end and described diode, also is connected a resettable fuse.
5. interface protective circuit according to claim 3, is characterized in that, between the negative pole end of described power input interface positive terminal and described diode, also is connected a resettable fuse.
6. according to the described interface protective circuit of claim 4 or 5, it is characterized in that, described sampling resistor R1 is adjustable resistance.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013204036075U CN203339652U (en) | 2013-07-08 | 2013-07-08 | Interface protection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2013204036075U CN203339652U (en) | 2013-07-08 | 2013-07-08 | Interface protection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203339652U true CN203339652U (en) | 2013-12-11 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2013204036075U Expired - Fee Related CN203339652U (en) | 2013-07-08 | 2013-07-08 | Interface protection circuit |
Country Status (1)
| Country | Link |
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| CN (1) | CN203339652U (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104734115A (en) * | 2015-02-10 | 2015-06-24 | 程永 | Simple overvoltage protector |
| CN106160199A (en) * | 2016-08-29 | 2016-11-23 | 浪潮电子信息产业股份有限公司 | A kind of prevent the device of whole machine cabinet power down, rack and method |
| CN106877304A (en) * | 2017-04-25 | 2017-06-20 | 航天科技控股集团股份有限公司 | A kind of Vehicular power protective circuit |
| CN107749611A (en) * | 2017-11-16 | 2018-03-02 | 盈帜科技（常州）有限公司 | A kind of overvoltage crowbar |
| CN110829357A (en) * | 2019-09-29 | 2020-02-21 | 深圳市捷高电子科技有限公司 | Intelligent overvoltage and overcurrent protection method |
| CN111313364A (en) * | 2019-11-29 | 2020-06-19 | 南通同洲电子有限责任公司 | Overvoltage protection device and overvoltage protection method |
-
2013
- 2013-07-08 CN CN2013204036075U patent/CN203339652U/en not_active Expired - Fee Related
Cited By (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104734115A (en) * | 2015-02-10 | 2015-06-24 | 程永 | Simple overvoltage protector |
| CN106160199A (en) * | 2016-08-29 | 2016-11-23 | 浪潮电子信息产业股份有限公司 | A kind of prevent the device of whole machine cabinet power down, rack and method |
| WO2018040777A1 (en) * | 2016-08-29 | 2018-03-08 | 浪潮电子信息产业股份有限公司 | Device, cabinet, and method for preventing power outage of entire cabinet |
| CN106160199B (en) * | 2016-08-29 | 2019-03-12 | 浪潮电子信息产业股份有限公司 | A kind of device preventing whole machine cabinet power down, cabinet and method |
| US11422604B2 (en) | 2016-08-29 | 2022-08-23 | Inspur Electronic Information Industry Co., Ltd. | Device, cabinet, and method for preventing power outage of entire cabinet |
| CN106877304A (en) * | 2017-04-25 | 2017-06-20 | 航天科技控股集团股份有限公司 | A kind of Vehicular power protective circuit |
| CN107749611A (en) * | 2017-11-16 | 2018-03-02 | 盈帜科技（常州）有限公司 | A kind of overvoltage crowbar |
| CN110829357A (en) * | 2019-09-29 | 2020-02-21 | 深圳市捷高电子科技有限公司 | Intelligent overvoltage and overcurrent protection method |
| CN111313364A (en) * | 2019-11-29 | 2020-06-19 | 南通同洲电子有限责任公司 | Overvoltage protection device and overvoltage protection method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 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: 20131211 Termination date: 20180708 |
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| CF01 | Termination of patent right due to non-payment of annual fee |