CN106451647A

CN106451647A - Protective circuit

Info

Publication number: CN106451647A
Application number: CN201610978333.0A
Authority: CN
Inventors: 谢乐
Original assignee: Individual
Current assignee: Individual
Priority date: 2016-11-08
Filing date: 2016-11-08
Publication date: 2017-02-22

Abstract

The invention relates to a protective circuit. The protective circuit has the advantage of electronic equipment protection, such as a mobile phone, a camera, a tablet computer, a notebook, etc., by cutting off the power supply in the case of water inflow. The circuit comprises a water inflow detection circuit with water-absorbing materials, a battery powered switch control circuit and a charging switch control circuit. The device provides a good protection for waterlogged devices. According to the device, the maintenance after water inflow is simple, the probability of repair is high, and the loss of user is minimized.

Description

Protection circuit

Technical field

This circuit is related to a kind of protection circuit.The protection circuit can protect mobile phone, camera, panel computer, notebook Power supply is cut off in the case of water inlet Deng electronic equipment, this circuit detects circuit by the water inlet for including absorbent material, and battery is supplied Electric switch control circuit, charge switch controlling circuits, three parts constitute.

Background technology

Current phone, camera, panel computer, notebook, waits the electronic equipment that carries with increasingly to popularize, one in life Imprudence allows these electronic equipments to fall in water or ooze water, as water has electric conductivity, adds this class of electronic devices typically interior Put battery, non-dismountable, and or client do not recognize the necessity of horse back power-off, when often finding that product is abnormal Circuit has been damaged very seriously, and the probability of reparation is very little, and the difficulty of reparation is very big, causes mainboard to corrode, electric leakage, oxygen Change the even complicated problem of short circuit etc. to occur, the damage for causing electronic product is uncontrollable and irreversible.Not only electronics Product cannot repair and also electronic product inside the related important information that stores also be difficult to be transferred out, to the loss of client very Greatly.The present invention can be in the very first time of water inlet, from the direct power-off of the feeder ear of battery, it is to avoid allow circuit etch, oxidation, electric leakage The possibility that burns.As commonly used person normally cannot may think that electronic equipment in the case of use in electronic equipment water inlet Battery does not have electricity, the hazardous act being charged, and the protection circuit not only disconnects battery-end while detecting into water Power supply, and disconnect charging end supply input.Make the electronic equipment into water that the state of unpowered is in, allow the damage of circuit to drop To minimum, and then repair also simple, easily, allow the loss of user to be preferably minimized.

Content of the invention

Therefore, it is an object of the invention to provide a kind of circuit that can play power-off protection in the case of water inlet.

The protection circuit is made up of three partial circuits：First battery input switch control section H7.Second charge switch Control section H7.3rd water inlet detection control section H9.Battery input switch control section H7 is connected on battery and by protection electricity Between road, and it is connected with water inlet detection part.Charge switch control section is connected between charging input end and charging circuit, And it is connected with battery input switch control section outfan.

In the protection circuit, Q2, Q4, Q5 used are NPN triode.Q1, Q3 are N-channel type field effect transistor.

Description of the drawings

Fig. 1 is the schematic diagram of the present invention.

It is embodied as

In the state of circuit and do not intake normally, operation principle is as follows：A cell input terminal foot phase respectively with R1, R11 Even, and be connected with the S foot of Q1, another foot of R11 is connected with the G foot of Q1, the voltage for making the G foot of Q1 is high level, the S foot of Q1 with D foot is in not on-state, the D foot Non voltage output of Q1, and another foot of R1 is connected with G point, K point and R4, R7, R2, a foot It is connected and is connected with the C foot of Q5, the high level of R1 output is by another foot of R2 to Q2 when G point and K point are touched with conductor is short B foot, make the C foot of Q2 and the conducting of E foot, the E foot because of Q2 is connected to the ground, and in the case of Q2 conducting, the C foot of Q2 is equivalent to over the ground Short circuit, R3 connected with the C foot of Q2 is connected with the G foot of Q1 by another foot, and then the G foot voltage pull-down of Q1 is become low level, And then turning on the S foot of Q1 and D foot, D foot now has cell voltage to export.One foot of R4 is connected with the D foot of Q1, another foot of R4 It is connected with a foot of R2, another foot of R2 is connected with the B foot of Q2, so in the case that G point and K point are in and disconnect, the base of Q2 Pole B is also high level, and the conducting of Q2 is maintained, and then is maintained the conducting of Q1, even if therefore not connecing in G point and K point In the case of logical, cell voltage importation is able to normally.

Because Q1 is turned on, another foot of R10 connected with the D foot of Q1 is connected with a foot of R8, R9 respectively, another foot of R8 with Ground is connected, and another foot of R9 is connected with the B foot of Q4, is connected with the B foot of Q4 through R8, makes the B foot of Q4 in high level, and then makes The C foot of Q4 and the conducting of E foot, the E foot of Q4 is connected to the ground, and the C foot of Q4 is connected with a foot of R6, the G foot phase of another foot of R6 and Q3 Even, it is low level and then the G foot voltage pull-down of Q3, makes Q3 in the conduction state, the S foot of Q3 is connected with charging input end VIN, When charger is inserted, the S foot of Q3 and the conducting of D foot export charging voltage, can charge normal.

Water inlet detection part H2 is made up of L1, L2 and S, and this detection part is arranged at the position of easy water inlet, this test section Point H2 can arrange multiple in multiple positions in parallel as needed, and L1 is parallel adjacent disjunct wire with L2, and S is to be bonded at circuit board Go up and cover the water absorbing material of the W area between L1 and L2, when water is penetrated in circuit, as S has water absorption, now Water of the absorption on S serves as the electric conductor of L1 and L2, and L2 is connected with the D foot of Q1, makes the voltage of L2 by the electric conductivity of water L1 is made for high level, the foot of R12 another foot that is connected with L1 is connected with the B foot of Q5, and then turns on the C foot of Q5 and E foot, because of Q5 E foot be connected to the ground, and then cause and the connected Q2 of R2 B foot be low level, be not turned on the C foot of Q2 and E foot, and then make Q1 Control foot G keep high level, make the state of the S foot of Q1 and D foot in being not turned on, and then the D foot of Q1 do not have voltage output, this When electronic equipment be in unpowered state, because of the D foot Non voltage output of Q1, the R10 being attached thereto also no-voltage, and then make to pass through Base stage B of the Q4 that R9 is attached thereto is low level, and the C foot of Q4 and E foot are in not on-state, now when charger insert and Another foot of the connected R5 of charging input end VIN is also high level, and then so that the S foot of Q3 and D foot is not led with the G foot connected end of Q3 Logical, the D foot no charging voltage output of Q3.

After the water that absorbent material S absorbs has been done, although without water as conductor between L1 and L2, due to this When the S foot of Q1 and D foot be in not on-state, the D foot of Q1 does not have voltage, and L1, L2 have been low levels, and the B foot of Q2 is low Level, in not on-state, it is impossible to the G foot of Q1 down for low level, and the D foot of Q1 is still without voltage output, only Tactile power supply and charging circuit normal work again can just be made again with electric conductor G point and K point are short.

Entirely the circuit, outside L1, L2 and S absorbent material overlay area, all remaining in other described circuits Part sealing water-proofing treatment, causes the protection circuit cannot normal work with water-inlet-proof.

Normal condition：G point K point is short to be touched, and --- --- --- -- Q4 conducting ----Q3 is turned on for-Q1 conducting for-Q2 conducting

Flooded condition：----Q5 conducting ----Q2 is not turned on --- Q1 is not turned on --- -- Q4 is not turned on ----Q3 when S is adsorbed onto water It is not turned on.

Claims

1. a kind of protection circuit, its feature is that the protection circuit can disconnect cell input terminal after circuit is intake and powers, Disconnect charging input end to power.

2. protection circuit according to claim 1, once entering in guard mode is disconnected, can maintain always and supplying electrically disconnected shape State.

3. when battery accesses for the first time circuit or water inlet allows normal circuit operation again after reparation, it is necessary to manually trigger ability Make circuit normal power supply and charging again.

4. protection circuit according to claim 1 is made up of three parts：Water inlet of the Part I comprising water absorbing material is examined Survey part H2, Part II battery input switch control circuit H7, Part III charge switch controlling circuits H9.

5. water inlet detection part H2 according to claim 4 is connected with battery input switch part H7, battery input switch Control section H7 outfan is connected with charge switch controlling circuits H9.

6. water inlet detection part can be arranged in parallel multiple according to actual needs according to claim 4, be arranged at and easily enter The position of water, to increase the comprehensive of detection.