CN213521279U

CN213521279U - Charging and discharging different-port protection circuit capable of realizing one-way charging

Info

Publication number: CN213521279U
Application number: CN202021848310.6U
Authority: CN
Inventors: 霍文广; 刘志云; 池晨翔
Original assignee: Scud Fujian Electronic Co ltd
Current assignee: Scud Fujian Electronic Co ltd
Priority date: 2020-08-31
Filing date: 2020-08-31
Publication date: 2021-06-22
Anticipated expiration: 2030-08-31

Abstract

The utility model provides a charging and discharging different-port protection circuit with one-way charging, which is characterized in that a circuit breaker is adopted to connect the positive pole of a lithium battery in series as a temperature protection device; a field effect transistor is used as a switch of the charging control circuit. The temperature protection is realized through the temperature protection function of the circuit breaker, the charger provides a control signal level, the on-off of the charging loop is controlled by the switch of the field effect transistor, so that the charging port is uncharged when the battery is normally used, and the stability and the use safety of the battery protection circuit are improved. Meanwhile, a secondary protection circuit based on a field effect tube as an on-off switch is adopted, so that the battery can be protected under the condition of abnormity in use, and accidents are prevented.

Description

Charging and discharging different-port protection circuit capable of realizing one-way charging

Technical Field

The utility model relates to a battery charging supply circuit field especially relates to an one-way charging and discharging different port protection circuit that charges.

Background

In various electronic products, the power supply of the existing products is supplied by a lithium battery or a battery pack, the temperature protection of the lithium battery is realized by a host, and the battery has no temperature protection function. Some products are designed with a seat charging function, so the design of the battery is a charging and discharging different port, namely a charging port and a discharging port, the charging port is exposed outside and electrified for a long time, short circuit risks exist, and the product function is influenced by corrosion easily caused by long-term contact with sweat.

For temperature protection of a lithium battery, in the prior art, the temperature of a thermistor is usually detected by a host, and the temperature protection of the battery cannot be accurately performed.

SUMMERY OF THE UTILITY MODEL

In order to solve the defects of the prior art, the utility model provides a charging and discharging special-shaped port protection circuit scheme with multiple protection functions and one-way charging, which can automatically cut off the circuit when the temperature of the battery is too high; the charging port is not charged in a normal use state, and when the charger is connected, the charger can charge the battery.

The utility model discloses specifically adopt following technical scheme:

the utility model provides a different mouthful of protection circuit of charge-discharge that one-way charges which characterized in that: the positive pole of a lithium battery connected in series with a breaker is used as a temperature protection device; a field effect transistor is used as a switch of the charging control circuit.

Preferably, the method comprises the following steps: the device comprises a temperature protection device, a primary protection circuit, a secondary protection circuit, a charging control circuit, a discharging port and a charging port; the temperature protection device, the secondary protection circuit and the primary protection circuit are sequentially connected, and the primary protection circuit is connected with the charging port through the charging control circuit; the primary protection circuit is connected with the discharge port.

Preferably, the charge control circuit is composed of a field effect transistor Q3, a field effect transistor Q4, a field effect transistor Q5, a resistor R5, a resistor R6 and a resistor R7; the S pole of the field effect transistor Q3 is connected with the positive pole end of the lithium battery, the D pole is connected with the D pole of the field effect transistor Q4, and the G pole is connected with the D pole of the field effect transistor Q5; the resistor R5 is connected in parallel between the G pole and the S pole of the field effect tube Q3; the S pole of the field effect transistor Q4 is connected with the positive pole of the charging port, and the G pole is connected with the D pole of the field effect transistor Q5; the S pole of the field effect transistor Q5 is grounded, the G pole is connected with the control interface of the charging port through a resistor R6, and the G pole is grounded through a resistor R7.

Preferably, the primary protection circuit and the secondary protection circuit are respectively provided with a field effect transistor Q1 and a field effect transistor Q2 which are connected in series on the charging and discharging loop.

The utility model discloses and temperature protection and charger provide the control signal level are realized through the temperature protect function of circuit breaker to preferred scheme thereof, and the port that charges when the break-make that comes control charging circuit by field effect transistor's switch makes battery normal use is uncharged to improve battery protection circuit's stability and the security of using. Meanwhile, a secondary protection circuit based on a field effect tube as an on-off switch is adopted, so that the battery can be protected under the condition of abnormity in use, and accidents are prevented.

Drawings

The invention will be described in further detail with reference to the following drawings and detailed description:

FIG. 1 is a schematic block diagram of the overall structure of an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of an embodiment of the present invention (lithium battery-temperature protection device-secondary protection circuit-primary protection circuit-discharge port);

fig. 3 is a schematic diagram of a charging control circuit according to an embodiment of the present invention.

Detailed Description

In order to make the features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail as follows:

as shown in fig. 1, the circuit structure provided by this embodiment is composed of a temperature protection device, a primary protection circuit, a secondary protection circuit, a charge control circuit, a charge port, and a discharge port. Wherein, the positive pole of the lithium battery is connected with the temperature protection device; the temperature protection device is connected with the lithium battery and the primary protection circuit; the primary protection circuit is connected with the temperature protection device and the secondary protection circuit; the secondary protection circuit is connected with the discharge port, the charging control circuit and the primary protection circuit; the charging control circuit is connected with the charging port and the secondary protection circuit.

As shown in fig. 2 and 3, the charging port is specifically configured to be used as a battery charging port, and includes an interface J1 transient diode TVS 1.

The discharge port is used as a battery discharge port and comprises an interface J2, a capacitor C5 and a transient diode TVS 2.

The temperature protection device is used for over-temperature protection and over-current protection of the battery, and comprises a circuit breaker F1.

The primary protection circuit is used for protecting the battery from abnormal conditions during use and preventing accidents from happening and comprises a chip U1, a field effect transistor Q1, a resistor R1, a resistor R2, a resistor RS1, a capacitor C1 and a capacitor C4. In this embodiment, the chip U1 employs an S-82F1BAG battery protection IC.

The secondary protection circuit is used for protecting the battery under the condition of abnormity when the primary protection circuit fails, and preventing the battery from accidents, and comprises a chip U2, a field effect transistor Q2, a resistor R3, a resistor R4, a resistor RS2, a capacitor C2 and a capacitor C3. In this embodiment, the chip U2 employs an S-82F1BAH battery protection IC.

The charging control circuit is used for enabling the charging port to be conducted in a single direction, is not conducted in a normal use state, is conducted to charge the battery after being connected with the charger, and comprises a field effect transistor Q3, a field effect transistor Q4, a field effect transistor Q5, a resistor R5, a resistor R6 and a resistor R7.

As one of the core features of this embodiment, a circuit breaker F1 is used in the circuit to monitor the temperature and current of the lithium battery and to cut off the battery charging and discharging circuit when the temperature or current reaches a protection point. Compared with the prior art, the temperature protection function is introduced.

The design of the charging control circuit is the second core characteristic, in the circuit, R5 plays a role in limiting the D pole current of Q5, R7 is a bleeder resistor, the G pole of Q5 is pulled down, Q5 is used as a switch, and field effect transistors Q3 and Q4 are charging circuit switches. The CHG _ Ctrl is in a suspended state in a normal use state, R7 pulls down the G pole of Q5 to enable the G pole of Q5 to be at a low level, the D pole of Q5 is pulled up to a VBAT high level through R5, the G poles of Q3 and Q4 are also pulled to be at the VBAT high level, Q3 and Q4 are in an off state, and VCHG is not electrified; when the charger is connected, the CHG _ Ctrl is a high level signal, the G pole of the Q5 is high level, the D, S pole of the Q5 is conducted, the D pole of the Q5 is low level, the G poles of the Q3 and the Q4 are also pulled to be low level, and the Q3 and the Q4 are in a conducting state, so that the charger can normally charge the battery. In the middle of having avoided prior art, the port that charges exposes for a long time and is electrified, can have the short circuit risk to long-term contact sweat takes place easily to corrode the defect that influences the product function.

The scheme of the embodiment can be used in various electronic product application fields powered by lithium batteries, and can be used in single-section or multi-section battery protection application. The circuit breaker F1 can accurately protect the battery from over-temperature and cut off a charge-discharge loop, so that the danger of the battery is avoided. The voltage drop of the conducted Q3 and Q4 is very small and can be ignored almost, the static power consumption of the whole protection circuit is very low (can be as low as less than 10uA in practical application), the cost is very low, the circuit can effectively control the switch of a charging loop, and the use safety and reliability of the battery are ensured.

The present invention is not limited to the above-mentioned preferred embodiments, and any person can obtain various other types of one-way charging/discharging protection circuits with different ports, and all the equivalent changes and modifications made according to the claims of the present invention shall fall within the scope of the present invention.

Claims

1. The utility model provides a different mouthful of protection circuit of charge-discharge that one-way charges which characterized in that: the positive pole of a lithium battery connected in series with a breaker is used as a temperature protection device; a field effect transistor is used as a switch of the charging control circuit;

the method comprises the following steps: the device comprises a temperature protection device, a primary protection circuit, a secondary protection circuit, a charging control circuit, a discharging port and a charging port; the temperature protection device, the secondary protection circuit and the primary protection circuit are sequentially connected, and the primary protection circuit is connected with the charging port through the charging control circuit; the primary protection circuit is connected with the discharge port;

the charging control circuit is composed of a field effect transistor Q3, a field effect transistor Q4, a field effect transistor Q5, a resistor R5, a resistor R6 and a resistor R7; the S pole of the field effect transistor Q3 is connected with the positive pole end of the lithium battery, the D pole is connected with the D pole of the field effect transistor Q4, and the G pole is connected with the D pole of the field effect transistor Q5; the resistor R5 is connected in parallel between the G pole and the S pole of the field effect tube Q3; the S pole of the field effect transistor Q4 is connected with the positive pole of the charging port, and the G pole is connected with the D pole of the field effect transistor Q5; the S pole of the field effect transistor Q5 is grounded, the G pole is connected with the control interface of the charging port through a resistor R6, and the G pole is grounded through a resistor R7.

2. The charging and discharging different port protection circuit with one-way charging according to claim 1, characterized in that: the primary protection circuit and the secondary protection circuit are respectively provided with a field effect transistor Q1 and a field effect transistor Q2 which are connected in series on the charging loop and the discharging loop.