CN201898656U - Protective circuit of waterlogged mobile terminal circuit board and mobile terminal - Google Patents
Protective circuit of waterlogged mobile terminal circuit board and mobile terminal Download PDFInfo
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- CN201898656U CN201898656U CN2010205253530U CN201020525353U CN201898656U CN 201898656 U CN201898656 U CN 201898656U CN 2010205253530 U CN2010205253530 U CN 2010205253530U CN 201020525353 U CN201020525353 U CN 201020525353U CN 201898656 U CN201898656 U CN 201898656U
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- portable terminal
- pin
- effect transistor
- field effect
- circuit board
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- 230000001681 protective effect Effects 0.000 title claims abstract description 23
- 230000005669 field effect Effects 0.000 claims abstract description 29
- 238000001514 detection method Methods 0.000 claims abstract description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 31
- 238000004078 waterproofing Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
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Abstract
The utility model discloses a protective circuit of a waterlogged mobile terminal circuit board and a mobile terminal. The protective circuit comprises a first triode, a first field effect transistor, a first detecting pin and a second detecting pin, wherein the base of the first triode is connected with a first resister and a second resister; the first resister is connected with the positive electrode of a battery; the second resister is connected with the first detecting pin; the collector of the first triode is connected with the grid electrode of the first field effect transistor; the emitter of the first triode is grounded; the source and the drain of the first field effect transistor are connected in series on the power supply path of the mobile terminal. With the adoption of the protective circuit, the detection of waterlogged mobile terminal hardware can be accomplished; and then power supplied by the battery is quickly cut off by the hardware, therefore, the mobile terminal circuit board is effectively protected.
Description
Technical field
The utility model relates to a kind of portable terminal reliability protection field, guard method and circuit and a kind of mobile phone that utilizes described protective circuit of in particular a kind of portable terminal water inlet back circuit board.
Background technology
Under the situation of portable terminal water inlet; in order effectively to protect the circuit board of portable terminal; need cut off being connected of battery and mobile terminal circuit plate fast and effectively; at present; the tight structural design of general employing prevents the into purpose of water to reach; but along with the function of portable terminal is more and more; the interface that is connected with peripheral hardware is more and more; become increasingly complex; the difficulty of portable terminal waterproof is also increasing; for example, the Micro USB of mobile phone (Micro Universal Serial Bus micro universal data/address bus) interface, 3.5mm standard earphone jack or the like.Existing portable terminal waterproof measure can not effectively solve waterproof problem.
Therefore, prior art has yet to be improved and developed.
The utility model content
The purpose of this utility model is to provide the protective circuit of a kind of portable terminal water inlet back circuit board, is intended to solve the waterproof problem that existing portable terminal effectively solved because of being difficult to of causing of function and structural change.
The technical solution of the utility model is as follows:
The protective circuit of a kind of portable terminal water inlet back circuit board, it comprises that first triode, first field effect transistor, first detect pin and second and detect pin, the base stage of described first triode connects first resistance and second resistance, first resistance connects the positive pole of battery, and second resistance connects first and detects pin; The collector electrode of described first triode connects the grid of first field effect transistor, the grounded emitter of described first triode; The source electrode of described first field effect transistor and drain electrode are connected on the supply path of portable terminal.
The protective circuit of described portable terminal water inlet back circuit board, wherein, it is respectively the 4th pin and the 5th pin of micro universal data bus interface that the described first detection pin and second detects pin.
The protective circuit of described portable terminal water inlet back circuit board, wherein, the described first detection pin and second detects pin and is arranged in the earphone jack.
The protective circuit of described portable terminal water inlet back circuit board, wherein, described field effect transistor is a P type field effect transistor.
The protective circuit of described portable terminal water inlet back circuit board wherein, also is provided with one the 3rd resistance between the source electrode of described first field effect transistor and the grid.
A kind of portable terminal, wherein, described portable terminal comprises above-mentioned protective circuit.
Described portable terminal, wherein, described portable terminal is a mobile phone.
The beneficial effects of the utility model: the utility model makes the characteristic of short circuit by the electric conductivity that utilizes water; the interface of water is provided with special-purpose hardware short-circuit detecting circuit being easy to into; realization is for the hardware detection of portable terminal water inlet; then; same use hardware mode fast shut-off battery is effectively protected the circuit board of portable terminal to the power supply of portable terminal.
Description of drawings
Fig. 1 is a kind of waterproofing protection circuit diagram that is arranged on the Micro USB interface place of mobile phone that the utility model embodiment one provides;
Fig. 2 is the waterproofing protection circuit of Fig. 1 and the circuit diagram that cell phone charging circuit combines.
Embodiment
For making the purpose of this utility model, technical scheme and advantage clearer, clear and definite, below the utility model is further described with reference to the accompanying drawing embodiment that develops simultaneously.
The guard method of a kind of portable terminal water inlet back circuit board that the utility model embodiment provides; its specific design principle is: the conductivity of utilizing water; the external interface place of water is provided with special-purpose hardware short-circuit detecting circuit being easy to into; realization is for the hardware detection of mobile phone water inlet; and utilize of the power supply of hardware switch circuit fast shut-off battery of mobile phone to mobile phone, effectively protect circuit board of mobile phone.
Described hardware detecting circuit is arranged on micro universal data bus interface place, utilizes the detection of the pin realization of interface to water inlet.Described hardware detecting circuit also can be arranged on the pair of metal sheet in the earphone jack simultaneously, and one of them is as detecting shell fragment connection hardware switching circuit, and another is as grounding elastic part ground connection.In order better to realize the water inlet protection, described testing circuit can be arranged on the position of any easy water inlet of portable terminal.
Referring to Fig. 1, present embodiment provides a kind of waterproofing protection circuit that is arranged on the Micro USB interface place of mobile phone, it comprises that it is the 5th pin GND of Micro USB interface that the first triode Q2, the first field effect transistor Q1, first detect the 4th pin ID and the second detection pin that pin is the Micro USB interface, the base stage of the described first triode Q2 connects first resistance R 1 and second resistance R 2, first resistance R 1 connects the positive pole of battery, and second resistance R 2 connects first and detects pin; The collector electrode of the described first triode Q2 connects the grid of the first field effect transistor Q1, the grounded emitter of the described first triode Q2; The source electrode of the described first field effect transistor Q1 and drain electrode are connected on the supply path of portable terminal.Also be provided with one the 3rd resistance R 3 between the source electrode of the described first field effect transistor Q1 and the grid, be used for to the grid making alive.
The described first field effect transistor Q1 is that a P type field effect transistor is the PMOS pipe, and described PMOS pipe requires overcurrent capability greater than 2A, guarantees the powered battery ability of mobile phone normal operating conditions.
Interface is the Micro USB connector of standard 5 pins among Fig. 1, do not possess OTG function (On The Go for general mobile phone, equipment with this function, can be used as USB hos t main equipment), thereby the 4th pin ID do not use, in the utility model, just be used as the detection pin of detection of handset water inlet short circuit.Can also save the setting that detects pin, make design easier.
At mobile phone not under the water inlet state, other earth signal insulation of ID pin and GND pin or mobile phone, keep open-circuit condition, at this moment the ID pin is in vacant state, the base stage of the first triode Q2 is connected with anode by first resistance R 1, be high level, the first triode Q2 is in conducting state, the grid of the collector electrode of Q2 and the first field effect transistor Q1 is pulled to low level, the pressure reduction VGS that causes the grid of the first field effect transistor Q1 and source electrode is a negative value and less than the turn-on threshold of the first field effect transistor Q1, the first field effect transistor Q1 conducting.
For the PMOS pipe, turn-on threshold VGS (th) is a negative value, also can be expressed as here: VGS is a negative value, and the absolute value of VGS that is to say and satisfies turn-on condition greater than the absolute value of turn-on threshold VGS (th).Electric current is powered to mobile phone by source electrode and the drain electrode of the first field effect transistor Q1; If mobile phone water inlet, the ID pin can with the short circuit of GND pin, the base stage of the first triode Q2 pulled down to low level by second resistance R 2.This moment, base voltage was the voltage VR2 on second resistance R 2, and its value is:
VR2=V*R2/ (R1+R2) ... ... ... ... formula (1)
In the following formula, V is a cell voltage, and first resistance R 1 selects bigger resistance to flow through the electric current of first resistance R 1 with minimizing, reduces the power consumption of mobile phone, general first resistance R 1 is the resistance of 100K, and the selection of second resistance R 2 must make the conducting voltage of the value of VR2 less than the first triode Q2.(R1 and R2 will select suitable resistance for use to guarantee to reach required level under the different conditions)
According to formula (1) as can be known, if the mobile phone water inlet, then the first triode Q2 ends.Then the grid of the first field effect transistor Q1 is a high level, its value also equals source voltage for cell voltage, the voltage that causes the grid of the first field effect transistor Q1 and source electrode is zero can not satisfy turn-on condition, and then the first field effect transistor Q1 ends, and battery was cut off with being connected of circuit board of mobile phone.Because these all are the hardware protection actions, speed is very fast, can effectively protect circuit board of mobile phone not to be damaged.
The described first detection pin and second detects pin and also can be arranged in the earphone jack, be welded on the place that the earphone socket on the pcb board is intake easily such as detecting pin, be welded on the detection of first on pcb board pin and be connected to second resistance R 2 by the PCB cabling, second detect pin be welded on first detect pin near, spacing is about 0.5mm, is welded on the detection of second on PCB pin and is connected with the ground of mobile phone by the PCB cabling.When the mobile phone water inlet, cause first to detect the pin and the second detection pin short circuit, protection philosophy is with top described the same.The general mobile phone place of easy water inlet is exactly the position of some sockets, so that test point all is placed on socket position is more effective.
In addition, the charging circuit of mobile phone can be avoided described protective circuit.When cell-phone charging, charging circuit will separate with the power supply circuits that comprise described protective circuit, and promptly charging current is directly passed through the positive pole of Charge Management unit to battery from charger, rather than charging current is oppositely got back to battery by the PMOS pipe.Referring to shown in Figure 2: charger connects the cell-phone charging module, and described cell-phone charging module directly connects the positive pole of battery.During cell-phone charging, electric current enters the positive pole of battery then by the charger cell-phone charging module of flowing through, and charges the battery.
A kind of portable terminal is characterized in that, described portable terminal comprises above-mentioned protective circuit.Described portable terminal is mobile phone, mobile TV etc.
Should be understood that; application of the present utility model is not limited to above-mentioned giving an example; for those of ordinary skills, can be improved according to the above description or conversion, all these improvement and conversion all should belong to the protection range of the utility model claims.
Claims (7)
1. the protective circuit of circuit board after a portable terminal is intake, it is characterized in that, comprise that first triode, first field effect transistor, first detect pin and second and detect pin, the base stage of described first triode connects first resistance and second resistance, first resistance connects the positive pole of battery, and second resistance connects first and detects pin; The collector electrode of described first triode connects the grid of first field effect transistor, the grounded emitter of described first triode; The source electrode of described first field effect transistor and drain electrode are connected on the supply path of portable terminal.
2. the protective circuit of portable terminal water inlet according to claim 1 back circuit board is characterized in that it is respectively the 4th pin and the 5th pin of micro universal data bus interface that the described first detection pin and second detects pin.
3. the protective circuit of portable terminal water inlet according to claim 1 back circuit board is characterized in that the described first detection pin and second detects pin and is arranged in the earphone jack.
4. the protective circuit of portable terminal water inlet according to claim 1 back circuit board is characterized in that described field effect transistor is a P type field effect transistor.
5. the protective circuit of portable terminal water inlet according to claim 1 back circuit board is characterized in that, also is provided with one the 3rd resistance between the source electrode of described first field effect transistor and the grid.
6. a portable terminal is characterized in that, described portable terminal comprises the described protective circuit of claim 1-5.
7. the protective circuit of portable terminal water inlet according to claim 6 back circuit board is characterized in that described portable terminal is a mobile phone.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205253530U CN201898656U (en) | 2010-09-01 | 2010-09-01 | Protective circuit of waterlogged mobile terminal circuit board and mobile terminal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205253530U CN201898656U (en) | 2010-09-01 | 2010-09-01 | Protective circuit of waterlogged mobile terminal circuit board and mobile terminal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201898656U true CN201898656U (en) | 2011-07-13 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010205253530U Expired - Fee Related CN201898656U (en) | 2010-09-01 | 2010-09-01 | Protective circuit of waterlogged mobile terminal circuit board and mobile terminal |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201898656U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106451647A (en) * | 2016-11-08 | 2017-02-22 | 谢乐 | Protective circuit |
| CN107300965A (en) * | 2017-05-12 | 2017-10-27 | 青岛海信移动通信技术股份有限公司 | The implementation method and device of a kind of USB interface waterproof |
| WO2018014836A1 (en) * | 2016-07-18 | 2018-01-25 | 中兴通讯股份有限公司 | Warning processing method, apparatus and terminal |
| CN108879598A (en) * | 2017-05-12 | 2018-11-23 | 展讯通信（上海）有限公司 | USB interface protects circuit and electronic equipment |
| WO2020073253A1 (en) * | 2018-10-10 | 2020-04-16 | 华为技术有限公司 | Method, circuit and electronic device for detecting water immersion |
-
2010
- 2010-09-01 CN CN2010205253530U patent/CN201898656U/en not_active Expired - Fee Related
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2018014836A1 (en) * | 2016-07-18 | 2018-01-25 | 中兴通讯股份有限公司 | Warning processing method, apparatus and terminal |
| CN106451647A (en) * | 2016-11-08 | 2017-02-22 | 谢乐 | Protective circuit |
| CN107300965A (en) * | 2017-05-12 | 2017-10-27 | 青岛海信移动通信技术股份有限公司 | The implementation method and device of a kind of USB interface waterproof |
| CN108879598A (en) * | 2017-05-12 | 2018-11-23 | 展讯通信（上海）有限公司 | USB interface protects circuit and electronic equipment |
| CN108879598B (en) * | 2017-05-12 | 2019-12-13 | 展讯通信（上海）有限公司 | USB interface protection circuit and electronic equipment |
| WO2020073253A1 (en) * | 2018-10-10 | 2020-04-16 | 华为技术有限公司 | Method, circuit and electronic device for detecting water immersion |
| US11566964B2 (en) | 2018-10-10 | 2023-01-31 | Huawei Technologies Co., Ltd. | Water ingress detection method and circuit, and electric device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110713 Termination date: 20130901 |