CN113890131A - Waterproof protection method for low-cost battery charging interface - Google Patents
Waterproof protection method for low-cost battery charging interface Download PDFInfo
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- CN113890131A CN113890131A CN202111025559.6A CN202111025559A CN113890131A CN 113890131 A CN113890131 A CN 113890131A CN 202111025559 A CN202111025559 A CN 202111025559A CN 113890131 A CN113890131 A CN 113890131A
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- charging interface
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/0047—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries with monitoring or indicating devices or circuits
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/007—Regulation of charging or discharging current or voltage
- H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Charge And Discharge Circuits For Batteries Or The Like (AREA)
Abstract
The invention discloses a low-cost waterproof protection method for a battery charging interface, which comprises a battery, a direct-current charging input interface and a one-way control circuit connected with the battery and the direct-current charging input interface, wherein the one-way control circuit consists of a P-channel field effect transistor D1, a diode D2, a triode Q1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5 and a battery circuit. According to the waterproof protection method for the low-cost battery charging interface, the switching characteristic of a field effect transistor device, the advantages of low on-resistance and low voltage difference are utilized, and the on-off of the field effect transistor is controlled by automatically detecting whether the input voltage exists in the charging input interface, so that the one-way conduction of a circuit is controlled, and the condition that the battery supplies power to the charging interface when the input voltage does not exist in the charging interface is avoided; when the charging port has no voltage, the field effect tube is cut off, and the circuit between the battery and the charging port is cut off, so that the damage to equipment caused by the outflow of the battery through the charging port is effectively prevented.
Description
Technical Field
The invention relates to the technical field of waterproof of battery charging interfaces, in particular to a waterproof protection method of a low-cost battery charging interface.
Background
Many electronic products are portable by using a built-in battery mode, and such a mode usually reserves a built-in battery charging interface on a device shell to facilitate charging the device when the device is not powered. However, in application scenes such as rain or underwater, a voltage difference exists between the two electrodes of the reserved interface, and after a circuit at the interface is in contact with electrolyte such as water, the electrode reed of the interface can be corroded by electrolysis and even an equipment circuit is directly short-circuited, so that equipment is damaged. Such electronic devices are often built with battery charge management circuitry or physically sealed at the charging interface. The charge management circuit can prohibit the reverse flow of the battery current, and the physical seal can prevent the interface circuit from contacting electrolyte such as water, so that the equipment is in a protection state.
When using the physics sealed mode to carry out water protection to equipment, can increase casing grinding apparatus expense, influence the casing pleasing to the eye, improve the casing design degree of difficulty and the reliability is lower, very easily because cause damage beyond the equipment such as vibrations. When the charging management circuit is used, a common mode is a mode that a charging and discharging management chip and a common diode construct an anti-reverse circuit, and the charging and discharging management chip has high safety and stability, but the cost is high. The scheme for constructing the anti-reverse-current circuit by using the common diode is low in cost, but the common diode has large leakage current, and after a charging interface is contacted with electrolyte such as water, a metal reed can be slowly corroded by point decomposition, so that the service life of equipment can be influenced.
The invention adopts the advantage of small on-resistance of the field effect device, realizes the anti-reflux circuit of the battery through certain circuit combination, can obviously reduce the leakage current and electrolytic corrosion speed of the charging interface reed in the electrolyte, has extremely low cost, and can be widely applied to the waterproof treatment of electronic equipment.
Disclosure of Invention
The invention aims to provide a low-cost waterproof protection method for a battery charging interface, so as to solve the problems in the background technology.
In order to achieve the purpose, the invention provides the following technical scheme: the low-cost battery charging interface waterproof protection method comprises a battery, a direct-current charging input interface and a one-way control circuit connected with the battery and the direct-current charging input interface, wherein the one-way control circuit consists of a P-channel field-effect tube D1, a diode D2, a triode Q1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5 and a battery circuit, wherein the R1 and the R2 form a voltage division bias circuit for controlling the on-off of the P-channel field-effect tube, the R3 and the R4 form a voltage division bias circuit for controlling the on-off of the triode Q1, and the P-channel field-effect tube realizes the blocking work from the positive electrode of the battery to the charging input port because the voltage of the battery end is higher than the voltage of the charging port when a system is not connected with charging equipment, and the method particularly comprises the following steps:
the method comprises the following steps: when the charging equipment is not plugged into the equipment, the charging input interface is in an open-circuit state, and the voltage of the battery is isolated from the charging interface;
step two: when the equipment is plugged into the charging equipment, the charging input interface is connected with voltage to charge the battery;
step three: when the equipment is fully charged, the charger of the equipment is unplugged at the moment, and the charging interface is in an open circuit state at the moment;
step four: when the device is in an operating state, if the charging interface of the device is in an electrolyte environment, the charging interface is in a short-circuit state at the moment, and the battery voltage is isolated from the charging interface.
Preferably, in the first step, since the P-channel fet D1 is in a non-conducting state, the substrate of the transistor Q1 is grounded through R4 and R5, Q1 is turned off, and the G pole of the D1 fet is in an off state as well as the S pole voltage and D1.
Preferably, in the second step, since D1 is not turned on, when the current flows through R3 and R4, Q1 is turned on, R1 and R2 divide the output voltage to obtain VGS and satisfy the value voltage of the fet, at this time, fet D1 is turned on, the resistance between drain D and source is the on internal resistance of the fet, when fet D1 is turned on, the parasitic diode on D1 is bypassed, the current flows through the fet, and since the input voltage at the charging port is higher than the battery voltage, the current flows through the D pole of the fet to the S pole to charge the battery.
Preferably, in the third step, at this time, since the battery voltage cannot be reversely output around the diode D2, no current flows through R3 and R4, Q1 is turned off, and no current flows through R1 and R2, VGS of the fet is 0, the fet D1 is turned off, the battery voltage is isolated from the charging interface, and the leakage current of the fet is much smaller than that of the diode D2.
Preferably, in the fourth step, the resistor R5 is grounded through R3 and R4, the transistor Q1 is turned off, no current flows through R1 and R2, so VGS of the fet is 0, and the fet D1 is turned off.
Preferably, the resistances of the R1 and the R2 may be selected according to a threshold voltage VGS of the P-channel fet D1, and the resistances of the R3 and the R4 may be selected according to parameters of the NPN transistor Q1.
Preferably, the unidirectional control circuit effectively reduces the electrolytic corrosion speed of the plug-in reed in the electrolyte.
Preferably, the unidirectional control circuit is internally provided with threshold control, the threshold control can be realized in various modes, and the polarity of the input power supply can be detected in a combined mode of PN junction transistors such as resistors in series connection, in parallel connection, in a diode, in a triode and the like or by using an integrated circuit, so that the threshold voltage of the field effect transistor is controlled.
Compared with the prior art, the invention has the beneficial effects that:
(1) the field effect transistor is controlled to be switched on and off by automatically detecting whether the charging input interface has input voltage or not by utilizing the switching characteristics of the field effect transistor device and the advantages of low on-resistance and low voltage difference, so that the unidirectional switching-on of a circuit is controlled, and the battery is prevented from supplying power to the charging port when the charging port does not have the input voltage. When the charging port has voltage, the field effect tube is conducted, and the charger normally charges the battery because the voltage of the charging port is greater than the voltage of the battery; when the charging port has no voltage, the field effect tube is cut off, and the circuit between the battery and the charging port is cut off, so that the damage to equipment caused by the outflow of the battery through the charging port is effectively prevented.
(2) The on-off of a field effect transistor on a charging circuit is controlled by automatically detecting whether charging voltage exists or not; the threshold control part can be realized in various modes, and can detect the polarity of an input power supply by a combination mode of PN junction transistors such as resistor series, parallel, diode, triode and the like or by using an integrated circuit, thereby generating the threshold voltage of a control field effect transistor; the point-resolved corrosion speed of the reed of the charging port is reduced by utilizing the characteristic of extremely low leakage current of the field effect transistor.
(3) The battery charging port can be protected from water by using a plurality of resistors, a triode, a diode and a field effect transistor, so that the cost is extremely low; the traditional source input and drain output typical connection mode of the field effect transistor is broken through, the drain input and source output connection mode is used, and meanwhile, a bias circuit bootstrap function of the field effect transistor is achieved by using a parasitic diode in the field effect transistor.
Drawings
FIG. 1 is a block diagram of a charging process in the prior art;
FIG. 2 is a flow chart of a waterproof protection method for a charging interface according to the present invention;
FIG. 3 is a one-way circuit diagram of a P-channel FET in accordance with the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Referring to fig. 1-3, wherein fig. 1 is a block diagram of a charging process in the prior art, the present invention provides a technical solution: a low-cost waterproof protection method for a battery charging interface comprises a battery, a direct-current charging input interface and a one-way control circuit connected with the battery and the direct-current charging input interface, wherein the one-way control circuit consists of a P-channel field effect transistor D1, a diode D2, a triode Q1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5 and a battery circuit, wherein the R1 and the R2 form a voltage division bias circuit for controlling the on-off of the P-channel field effect transistor, the R3 and the R4 form a voltage division bias circuit for controlling the on-off of the triode Q1, the resistance values of the R1 and the R2 can be selected according to the actually selected threshold voltage VGS of the P-channel field effect transistor D1, the resistance values of the R3 and the R4 can be selected according to the parameters of an NPN-type triode Q1, and the voltage of the battery end is higher than the voltage of the charging interface when a system is not connected with charging equipment, so that the P-channel field effect transistor realizes the blocking work from the positive electrode of the battery to the charging input interface, and the one-way control circuit is internally provided with threshold control, the threshold control can be realized in various ways, and the polarity of the input power can be detected by a combination mode of PN junction transistors such as resistor series, parallel, diode, triode and the like or by using an integrated circuit, so as to generate the threshold voltage for controlling the field effect transistor, and the method specifically comprises the following steps:
the method comprises the following steps: when the charging equipment is not plugged into the equipment, the charging input interface is in an open-circuit state, the battery voltage is isolated from the charging interface, and because the P-channel field effect transistor D1 is in a non-conduction state, the triode Q1 substrate is grounded through R4 and R5, Q1 is turned off, the G pole of the D1 field effect transistor is the same as the S pole voltage, and D1 is also in a turn-off state;
step two: when the charging equipment is plugged into the equipment, the charging input interface is connected with voltage to charge the battery, because D1 is not conducted, after current flows through R3 and R4, Q1 is conducted, R1 and R2 divide the voltage of output voltage to obtain VGS and meet the voltage value of a field effect tube, at the moment, a field effect tube D1 is conducted, the resistance between a drain electrode D and a source electrode is the conduction internal resistance of the field effect tube, after the field effect tube D1 is conducted, a parasitic diode on D1 is bypassed, the current flows through the field effect tube, and because the input voltage of a charging port is higher than the voltage of the battery, the current flows to the S pole through the D pole of the field effect tube to charge the battery;
step three: when the device is fully charged, the charger of the device is unplugged, the charging interface is in an open circuit state, at the moment, the battery voltage cannot be reversely output due to the fact that the voltage of the battery is left and right of the diode D2, no current flows through the R3 and the R4, the Q1 is turned off, no current flows through the R1 and the R2, VGS of the field effect transistor is 0, the field effect transistor D1 is turned off, the battery voltage is isolated from the charging interface, and the leakage current of the field effect transistor is far smaller than that of the diode D2;
step four: when the equipment is in a working state, if the charging interface of the equipment is in an electrolyte environment, the charging interface is in a short-circuit state, the voltage of the battery is isolated from the charging interface, the resistor R5 is grounded through the R3 and the R4, the triode Q1 is cut, no current passes through the R1 and the R2, VGS of the field-effect tube is 0, the field-effect tube D1 is closed, and the electrolytic corrosion speed of the plug-in connector reed in the electrolyte is effectively reduced by the one-way control circuit.
The specific implementation mode of the invention is as follows: the field effect transistor is controlled to be switched on and off by automatically detecting whether the charging input interface has input voltage or not by utilizing the switching characteristics of the field effect transistor device and the advantages of low on-resistance and low voltage difference, so that the unidirectional switching-on of a circuit is controlled, and the battery is prevented from supplying power to the charging port when the charging port does not have the input voltage. When the charging port has voltage, the field effect tube is conducted, and the charger normally charges the battery because the voltage of the charging port is greater than the voltage of the battery; when the charging port has no voltage, the field effect tube is cut off, and the circuit between the battery and the charging port is cut off, so that the damage to equipment caused by the outflow of the battery through the charging port is effectively prevented. Those not described in detail in this specification are within the skill of the art.
Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.
Claims (8)
1. The waterproof protection method for the low-cost battery charging interface is characterized by comprising the following steps: the system comprises a battery, a direct current charging input interface and a one-way control circuit connected with the battery and the direct current charging input interface, wherein the one-way control circuit consists of a P-channel field effect transistor D1, a diode D2, a triode Q1, a resistor R1, a resistor R2, a resistor R3, a resistor R4, a resistor R5 and a battery circuit, wherein the R1 and the R2 form a voltage division bias circuit for controlling the on-off of the P-channel field effect transistor, and the R3 and the R4 form the voltage division bias circuit for controlling the on-off of the triode Q1, and because the voltage of the battery end is higher than the voltage of a charging port when the system is not connected with charging equipment, the P-channel field effect transistor realizes the blocking work from the positive electrode of the battery to the charging input port, and the method specifically comprises the following steps:
the method comprises the following steps: when the charging equipment is not plugged into the equipment, the charging input interface is in an open-circuit state, and the voltage of the battery is isolated from the charging interface;
step two: when the equipment is plugged into the charging equipment, the charging input interface is connected with voltage to charge the battery;
step three: when the equipment is fully charged, the charger of the equipment is unplugged at the moment, and the charging interface is in an open circuit state at the moment;
step four: when the device is in an operating state, if the charging interface of the device is in an electrolyte environment, the charging interface is in a short-circuit state at the moment, and the battery voltage is isolated from the charging interface.
2. The waterproof protection method for the low-cost battery charging interface according to claim 1, characterized in that: in the first step, since the P-channel fet D1 is in a non-conducting state, the substrate of the transistor Q1 is grounded through R4 and R5, Q1 is turned off, the G pole of the D1 fet is the same as the S pole voltage, and D1 is also in a turned off state.
3. The waterproof protection method for the low-cost battery charging interface according to claim 1, characterized in that: in the second step, since D1 is not turned on, after the current flows through R3 and R4, Q1 is turned on, R1 and R2 divide the output voltage to obtain VGS and satisfy the value voltage of the fet, at this time, fet D1 is turned on, the resistance between drain D and source is the on internal resistance of the fet, after fet D1 is turned on, the parasitic diode on D1 is bypassed, the current flows through the fet, and since the input voltage at the charging port is higher than the battery voltage, the current flows through the D pole of the fet to the S pole to charge the battery.
4. The waterproof protection method for the low-cost battery charging interface according to claim 1, characterized in that: in the third step, at this time, since the battery voltage cannot be reversely output around the diode D2, no current flows through the R3 and the R4, the Q1 is turned off, and no current flows through the R1 and the R2, VGS of the fet is 0, the fet D1 is turned off, the battery voltage is isolated from the charging interface, and the leakage current of the fet is much smaller than that of the diode D2.
5. The waterproof protection method for the low-cost battery charging interface according to claim 1, characterized in that: in the fourth step, the resistor R5 is grounded through the resistors R3 and R4, the transistor Q1 is turned off, no current passes through the resistors R1 and R2, therefore VGS of the fet is 0, and the fet D1 is turned off.
6. The waterproof protection method for the low-cost battery charging interface according to claim 1, characterized in that: the resistance values of the R1 and the R2 can be selected according to the threshold voltage VGS of the P-channel field effect transistor D1 which is actually selected, and the resistance values of the R3 and the R4 can be selected according to the parameters of the NPN type triode Q1.
7. The waterproof protection method for the low-cost battery charging interface according to claim 4, characterized in that: the one-way control circuit effectively reduces the electrolytic corrosion speed of the plug connector reed in the electrolyte.
8. The waterproof protection method for the low-cost battery charging interface according to claim 1, characterized in that: the unidirectional control circuit is internally provided with threshold control, the threshold control can be realized in various modes, and the polarity of an input power supply can be detected in a combined mode of PN junction transistors such as resistors in series connection, in parallel connection, in a diode, in a triode and the like or by using an integrated circuit, so that the threshold voltage of the field effect transistor is controlled.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111025559.6A CN113890131A (en) | 2021-09-02 | 2021-09-02 | Waterproof protection method for low-cost battery charging interface |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111025559.6A CN113890131A (en) | 2021-09-02 | 2021-09-02 | Waterproof protection method for low-cost battery charging interface |
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| CN113890131A true CN113890131A (en) | 2022-01-04 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN117353421A (en) * | 2023-10-10 | 2024-01-05 | 重庆神缘智能科技有限公司 | Optimization method and optimization circuit for power isolation |
| WO2024036976A1 (en) * | 2022-08-15 | 2024-02-22 | 兆略有限公司 | Underwater cleaning robot with rechargeable battery |
-
2021
- 2021-09-02 CN CN202111025559.6A patent/CN113890131A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024036976A1 (en) * | 2022-08-15 | 2024-02-22 | 兆略有限公司 | Underwater cleaning robot with rechargeable battery |
| CN117353421A (en) * | 2023-10-10 | 2024-01-05 | 重庆神缘智能科技有限公司 | Optimization method and optimization circuit for power isolation |
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