WO2019169541A1

WO2019169541A1 - Discharge indicator light control circuit and lithium battery power supply protection board thereof

Info

Publication number: WO2019169541A1
Application number: PCT/CN2018/078081
Authority: WO
Inventors: 姚启振
Original assignee: 深圳大力神科技有限公司
Priority date: 2018-03-06
Filing date: 2018-03-06
Publication date: 2019-09-12
Also published as: CN109417207A

Abstract

A discharge indicator light control circuit and a lithium battery power supply protection board thereof, for use in solving the technical problem of adverse effects on the existing lithium battery management system caused by not turning on taillights by means of high impedance. The indicator light control circuit comprises a weak current switch (SW4), an LED drive module (CT2), and an LED switch (SW3). The weak current switch (SW4) and the LED drive module (CT2) are connected to a lithium battery control module (CT1). A loop is formed between the LED switch (SW3) and a discharge indicator light (LOAD2), and a battery set (BY). The LED drive module (CT2) is connected to the LED switch (SW3). The discharge indicator light control circuit controls a main current discharge loop and a small current discharge loop, separately for effectively turning off an LED lamp. Current loops are used in parallel, which has no effect on the main current loop.

Description

Discharge indicator light control circuit and lithium battery power protection board

Technical field

The present invention relates to the field of lithium battery technology, and in particular, to a discharge indicator control circuit and a lithium battery power protection board.

Background technique

Lithium battery has the advantages of small volume, light weight, large specific energy, high specific power, no memory effect, small self-discharge, long cycle life, fast discharge, high efficiency, etc., and the lithium ion battery is a green battery. Secondary pollution caused by waste has gradually become the mainstream of power batteries. The lithium battery is generally managed by the lithium battery management system BMS. The BMS is installed inside the lithium battery pack, and the single chip is used as the control core. At the same time, the energy balance of each lithium battery can be realized, and the overcharge, over discharge and over Flow, temperature protection and short circuit protection, display various states of the battery pack through the LCD, and can read the historical performance status of each lithium battery through the reserved communication port. As shown in Figure 1, the lithium battery intelligent management system BMS is mainly composed of a charging module, a data acquisition module (including voltage, current, temperature data acquisition), an equalization module, a power calculation module, a data display module, and a storage communication module; The MCU is the main controller. By collecting the current information, it is judged whether the battery pack is charging, discharging or idle and whether there is overcurrent phenomenon, and the state is correspondingly processed. After collecting and analyzing the battery voltages of each section, the system determines whether to start the equalization module to energy balance the entire battery pack, and at the same time determine whether there is overcharge or overdischarge. Temperature collection is mainly used for over-temperature protection of the system. The working status, current, voltage of each section, remaining power and temperature information of the whole system will be displayed in real time through the LCD module.

When the lithium battery is discharged, the discharge indicator light is generally used to indicate that the lithium battery is in a discharge state, and the discharge indicator light is also called a tail light, generally using an LED lamp bead; when the lithium battery is discharged, the discharge indicator needs to be turned off. The existing lithium battery management system generally uses a high-impedance method to realize that the tail light is not bright. The specific implementation method is to make the digital multimeter voltage file test output voltage lower than 3V, that is, lower than the tail lamp LED 3V driving voltage, so that The tail light is not lit. Because the internal impedance of the digital multimeter voltage file is 10M or more, for example, the 48V battery pack should be displayed as 3V using the multimeter voltage file, and the output impedance of the power protection board must be 150M or more, which will cause the entire management system to be under such high impedance. Work will be greatly affected by the environment, resulting in failure to charge and discharge.

Summary of the invention

In view of this, the object of the present invention is to provide a discharge indicator control circuit and a lithium battery power protection board thereof, which can adversely affect the existing lithium battery management system by using a high impedance method to realize that the tail light is not bright. technical problem.

The technical solution adopted by the present invention to solve the above technical problems is as follows:

A discharge indicator control circuit includes a weak current switch SW4, an LED drive module CT2, and an LED switch SW3. The weak current switch and the LED drive module CT2 are connected to a lithium battery control module CT1, and the LED switch SW3 and The discharge indicator lamp and the battery pack BY form a loop, and the LED drive module CT2 is connected to the LED switch SW3.

Specifically, when SW4 is closed, the closing voltage is transmitted to CT1 at a high level, CT1 sends an open signal to the driving module CT2, and CT2 issues an open signal to drive the LED switch SW3, thereby illuminating the LED discharging indicator LOAD2, when SW4 is off When open, the disconnection voltage is low level and transmitted to CT1, CT1 sends a shutdown signal to the drive module CT2, and CT2 sends a shutdown signal to drive the LED switch SW3, thereby turning off the LED discharge indicator LOAD2, when the battery pack BY is used up. CT1 sends a battery over-discharge signal to the drive module CT2, and CT2 sends a shutdown signal to drive the LED switch SW3, thereby turning off the LED discharge indicator LOAD2, so as to prevent the battery pack from damaging the battery pack BY due to heavy discharge.

Further, one end of the weak current switch SW4 is connected to the negative pole of the battery pack, and the other end is connected to the lithium battery control module CT1.

Further, the weak current switch SW4 is connected in parallel with a discharge switch SW1, and the discharge switch SW1 is connected to the lithium battery control module CT1. The discharge switch SW1, the battery pack and a load LOAD1 form a loop.

Further, the weak current switch SW4 is connected in parallel with a charging switch SW1, and the charging switch SW1 is connected to the lithium battery control module CT1. The charging switch SW1, the battery pack and a charger CH form a loop.

According to an aspect of the present invention, a lithium battery power protection board is provided, which is composed of a lithium battery control module CT1, a discharge indicator lamp and the above-mentioned indicator control circuit, and the lithium battery control module CT1 includes a lithium battery protection IC. a chip, a charging MOS switch circuit, a discharge MOS switch circuit, and an overvoltage and undervoltage comparison circuit, wherein the lithium battery protection IC chip is connected to the battery pack through the overvoltage and undervoltage comparison circuit, the charging MOS switch circuit and the lithium a charging MOSFET control pin connection of the battery protection IC chip, the discharge MOS switch circuit is connected to a discharge MOSFET control pin of the lithium battery protection IC chip; the indicator control circuit comprises a weak current switch SW4 and an LED driving module CT2 And an LED switch SW3, wherein the weak current switch and the SW4 and the LED driving module CT2 are connected to the lithium battery protection IC chip.

Further, the lithium battery control module CT1 further includes a load and charge detection circuit, the load and the charge detection circuit are connected at one end to a negative connector of the charger or the load, and the other end is connected to the charger of the lithium battery protection IC chip. The sense pin is connected to the load sense pin.

Further, the lithium battery control module CT1 further includes a temperature detecting circuit and a protection delay circuit, and the temperature detecting circuit and the protection delay circuit are respectively connected to the temperature detecting pin and the extension of the lithium battery protection IC chip. Time pin.

Further, the overvoltage and undervoltage comparison circuit is connected at one end to the positive and negative terminals of the lithium battery, and at the other end to the positive terminal of the battery of the lithium battery protection IC chip.

The beneficial effects of the invention:

The discharge indicator control circuit and the lithium battery power protection board of the invention respectively control the main current discharge circuit and the small current discharge circuit to realize effective shutdown of the LED lamp. Since the current loop is used in parallel, there is no task impact on the main current loop. . Compared with other similar products, the tail light can be effectively extinguished, and the tail light is more stable under low impedance conditions. Compared with similar products, the high-impedance shutdown mode has obvious effects.

DRAWINGS

1 is a structural block diagram of a lithium battery management system according to an embodiment of the present invention;

2 is a structural block diagram of a discharge indicator control circuit according to an embodiment of the present invention;

3 is a structural block diagram of a power protection board for a lithium battery according to an embodiment of the present invention;

4 is a pin diagram of a lithium battery protection IC chip according to an embodiment of the present invention;

Among them, 10-lithium battery protection IC chip, 20-charge MOS switch circuit, 30-discharge MOS switch circuit, 40-indicator control circuit, 50-load and charge detection circuit, 60-temperature detection circuit, 70-overvoltage Pressure comparison circuit, 80-protection delay circuit, 90-battery pack.

The implementation, functional features, and advantages of the present invention will be further described in conjunction with the embodiments.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in order to make the present invention. It is understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

BMS is the first letter combination of BATTERY MANAGEMENT SYSTEM, which is called battery management system. Commonly known as battery nanny or battery housekeeper; battery management system (BMS) is mainly to intelligently manage and maintain each battery unit, prevent battery overcharge and over discharge, extend battery life, monitor battery status. The lithium battery management system is installed inside the lithium battery pack. With the single-chip microcomputer as the control core, it can realize over-charge, over-discharge, over-current, temperature protection and short-circuit protection while achieving energy balance of each lithium battery. The various states of the battery pack are displayed through the LCD, and the historical performance state of each of the lithium batteries can be read through the reserved communication port. As shown in Figure 1, the lithium battery intelligent management system is mainly composed of a charging module, a data acquisition module (including voltage, current, temperature data acquisition), an equalization module, a power calculation module, a data display module, and a storage communication module. The whole system uses the single-chip microcomputer as the main controller. By collecting the current information, it is judged whether the battery pack is charging, discharging or idle and whether there is overcurrent phenomenon, and the state is correspondingly processed. After collecting and analyzing the battery voltages of each section, the system determines whether to start the equalization module to energy balance the entire battery pack, and at the same time determine whether there is overcharge or overdischarge. Temperature collection is mainly used for over-temperature protection of the system. The working status, current, voltage of each section, remaining power and temperature information of the whole system will be displayed in real time through the LCD module.

Example 1

As shown in FIG. 2, an embodiment of the present invention provides a discharge indicator control circuit including a weak current switch SW4, an LED driving module CT2, and an LED switch SW3, the weak current switch and the LED driving module CT2 and lithium. The battery control module CT1 is connected, the LED switch SW3 forms a loop with the discharge indicator lamp and the battery pack BY, and the LED drive module CT2 is connected to the LED switch SW3.

When the LED taillight LOAD2 and the load LOAD1 are used in parallel as the load LOAD1, there is no CT2 and SW4. When SW1 is disconnected, the leakage current of CT1 causes LOAD2 to be slightly bright, which affects the consumer's judgment on whether the battery pack is turned off.

The one end of the weak current switch SW4 is connected to the negative pole of the battery pack, and the other end is connected to the lithium battery control module CT1.

The weak current switch SW4 is connected in parallel with a discharge switch SW1. The discharge switch SW1 is connected to the lithium battery control module CT1. The discharge switch SW1, the battery pack and a load LOAD1 form a loop.

The power switch SW4 is connected in parallel with a charging switch SW1. The charging switch SW1 is connected to the lithium battery control module CT1. The charging switch SW1, the battery pack and a charger CH form a loop.

Alternatively, SW1, SW2, SW3, and SW4 may be MOS transistors as switching devices. The LED driver module is a conventional LED lamp driver.

Example 2

According to an aspect of the present invention, as shown in FIG. 3, a lithium battery power protection board provided by the present invention is composed of a lithium battery control module CT1, a discharge indicator LOAD2, and the above indicator control circuit 40, the lithium The battery control module CT1 includes a lithium battery protection IC chip 10, a charging MOS switch circuit 20, a discharge MOS switch circuit 30, and an overvoltage and undervoltage comparison circuit 70, and the lithium battery protection IC chip 10 passes the overvoltage and undervoltage comparison circuit. 70 is connected to a battery pack 90, and the charge MOS switch circuit 20 is connected to a charge MOSFET control pin of the lithium battery protection IC chip 10, and the discharge MOS switch circuit 30 and the discharge MOSFET of the lithium battery protection IC chip 10 The control pin circuit includes a weak switch SW4, an LED drive module CT2, and an LED switch SW3, the weak switch and the SW4, the LED drive module CT2, and the lithium battery protection IC chip 10. connection.

The lithium battery control module CT1 further includes a load and charge detection circuit 50, and one end of the load and charge detection circuit 50 is connected to a negative connector of a charger or a load, and the other end is protected by the lithium battery protection IC chip 10. The charger sense pin is connected to the load sense pin.

The lithium battery control module CT1 further includes a temperature detecting circuit 60 and a protection delay circuit 80. The temperature detecting circuit 60 and the protection delay circuit 80 respectively connect the temperature detection of the lithium battery protection IC chip 10. Pin and delay pin.

The overvoltage and undervoltage comparison circuit 70 is connected at one end to the positive and negative terminals of the lithium battery 90, and at the other end to the positive terminal of the battery of the lithium battery protection IC chip 10.

As shown in FIG. 4, the pin diagram of the lithium battery protection IC chip of the model SH367107, the lithium battery protection IC chip of the above model can realize the construction of the power protection board, and of course, is not limited to the IC chip of the above model.

The discharge indicator control circuit and the lithium battery power protection board of the invention respectively control the main current discharge circuit and the small current discharge circuit to realize effective shutdown of the LED lamp. Since the current loop is used in parallel, there is no task impact on the main current loop. Compared with the existing method of improving the impedance of the main current loop to solve the dimming of the LED taillights. Compared with other similar products, the tail light can be effectively extinguished, and the tail light is more stable under low impedance conditions. Compared with similar products, the high-impedance shutdown mode has obvious effects.

In the description of the present patent, it is to be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", “Back”, “Left”, “Right”, “Vertical”, “Horizontal”, “Top”, “Bottom”, “Inside”, “Outside”, “Clockwise”, “Counterclockwise”, “Axial” The orientation or positional relationship of the indications such as "radial", "circumferential", "row", "column" and the like is based on the orientation or positional relationship shown in the drawings, and is merely for convenience of describing the patent and simplified description of the present invention. It is not intended or implied that the device or component referred to must have a particular orientation, is constructed and operated in a particular orientation, and thus is not to be construed as limiting the invention.

Moreover, the terms "first" and "second" are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, features defining "first" and "second" may expressly or implicitly include at least one of the features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless specifically defined otherwise.

In the invention patents, the terms "installation", "connected", "connected", "fixed", "fixed" and the like shall be understood broadly, and may be, for example, a fixed connection, unless otherwise specifically defined and defined. It can be a detachable connection, or can be integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, which can be the internal connection of two elements or the interaction of two elements. Unless otherwise expressly defined. For those skilled in the art, the specific meanings of the above terms in the patent of the present invention can be understood on a case-by-case basis.

In the present invention, the first feature "on" or "under" the second feature may be a direct contact of the first and second features, or the first and second features are passed through an intermediate medium, unless otherwise explicitly defined and defined. Indirect contact. Moreover, the first feature "above", "above" and "above" the second feature may be that the first feature is directly above or above the second feature, or merely that the first feature level is higher than the second feature. The first feature "below", "below" and "below" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely that the first feature level is less than the second feature.

Claims

A discharge indicator control circuit, comprising: a weak current switch, an LED drive module, and an LED switch, wherein the weak current switch and the LED drive module are connected to a lithium battery control module, the LED switch and the discharge indicator The lamp and the battery pack form a loop, and the LED drive module is coupled to the LED switch.
The discharge lamp control circuit according to claim 1, wherein one end of the weak current switch is connected to a negative pole of the battery pack, and the other end is connected to the lithium battery control module.
A discharge lamp control circuit according to claim 2, wherein said weak current switch is connected in parallel with a discharge switch, said discharge switch is connected to said lithium battery control module, said discharge switch, said battery The group and a load form a loop.
A discharge lamp control circuit according to claim 2, wherein said weak current switch is connected in parallel with a charging switch, said charging switch is connected to said lithium battery control module, said charging switch, said battery The group and a charger form a loop.
A lithium battery power protection board, comprising: a lithium battery control module, a discharge indicator lamp, and an indicator light control circuit according to any one of claims 1 to 4, wherein the lithium battery control module comprises lithium a battery protection IC chip, a charging MOS switch circuit, a discharge MOS switch circuit, and an overvoltage and undervoltage comparison circuit, wherein the lithium battery protection IC chip is connected to the battery pack through the overvoltage and undervoltage comparison circuit, and the charging MOS switch circuit and The lithium battery protects the charging MOSFET control pin of the IC chip, and the discharge MOS switch circuit is connected to the discharge MOSFET control pin of the lithium battery protection IC chip; the indicator control circuit includes a weak current switch and an LED driving mode The group and the LED switch, the weak current switch and the LED driving module are connected to the lithium battery protection IC chip.
A lithium battery power source protection board according to claim 5, wherein said lithium battery control module CT1 further comprises a load and charge detection circuit, said load and charge detection circuit having a negative end with a charger or a load The connector is connected, and the other end is connected to the charger detection pin and the load detection pin of the lithium battery protection IC chip.
The lithium battery power protection board according to claim 5, wherein the lithium battery control module CT1 further comprises a temperature detecting circuit and a protection delay circuit, the temperature detecting circuit and the protection delay circuit The temperature detection pin and the delay pin of the lithium battery protection IC chip are respectively connected.
A lithium battery power source protection board according to claim 5, wherein said overvoltage and undervoltage comparison circuit is connected at one end to a positive electrode and a negative electrode of the lithium battery, and the other end is connected to the lithium battery protection IC chip. Core positive terminal pin.