CN213521371U

CN213521371U - Electric quantity measurement charging circuit and electric quantity detection display system

Info

Publication number: CN213521371U
Application number: CN202022801340.8U
Authority: CN
Inventors: 宋浩然; 柴小杰; 赵茂辉; 凌灿; 黄思敏; 戴康明
Original assignee: Shenzhen WellD Medical Electronics Co ltd
Current assignee: Shenzhen WellD Medical Electronics Co ltd
Priority date: 2020-11-27
Filing date: 2020-11-27
Publication date: 2021-06-22
Anticipated expiration: 2030-11-27

Abstract

The utility model discloses an electric quantity measuring charging circuit and an electric quantity detecting and displaying system, wherein the electric quantity detecting and displaying system comprises a battery pack, a charger, a host and the electric quantity measuring charging circuit; the electric quantity measuring and charging circuit is connected with the battery pack, the charger and the host; the electric quantity measuring and charging circuit measures battery information of the battery pack, converts the format of the battery information and outputs the battery information to a display screen of the host computer for display; the electric quantity measuring and charging circuit is used for charging the battery pack according to the charging voltage transmitted by the charger. The battery information of the battery pack can be directly measured, and the problems that the existing battery electric quantity detection and display circuit can only detect the electric quantity and can not detect other battery information can be solved.

Description

Electric quantity measurement charging circuit and electric quantity detection display system

Technical Field

The utility model relates to the field of electronic technology, in particular to electric quantity measurement charging circuit and electric quantity detection display system.

Background

In the existing circuit for detecting and displaying the battery electric quantity, the battery voltage is connected to an AD pin of a single chip microcomputer, the electric quantity value is transmitted to an upper computer through a serial port by AD (analog-digital) sampling, and the upper computer displays the ratio of the current voltage and the full-charge voltage of the battery on an interface as the percentage of the electric quantity. The scheme only has a simple electric quantity display function, and the gear of the electric quantity can be only divided into 10 gears, so that the requirement of B ultrasonic on acquiring other information of the battery at present cannot be met.

Meanwhile, the resolution on the ADC pin of the single chip microcomputer is only 8 bits generally, so that the sampling precision is not high, and the accuracy of electric quantity is influenced. Moreover, the working speed of the single chip microcomputer cannot be fast, and the data quantity and the data frequency transmitted to the upper computer from the serial port cannot be fast; if the instantaneous power consumption of the machine is large, the displayed electric quantity value can be greatly floated. The low accuracy of the electric quantity detection also causes that various protection circuits cannot play an effective protection role.

In addition, the capacity of the battery is lost along with the use of the battery, and the simple percentage of the current voltage to the full-electricity voltage is used as the electricity quantity ratio, so that the capacity of the battery is more and more inaccurate along with the increase of the use times.

Thus, the prior art has yet to be improved and enhanced.

SUMMERY OF THE UTILITY MODEL

In view of the foregoing prior art, an object of the present invention is to provide an electric quantity measuring charging circuit and electric quantity detecting and displaying system, which can only detect the electric quantity and cannot detect other battery information.

In order to achieve the purpose, the utility model adopts the following technical proposal:

a kind of electric quantity measures the charging circuit, connect battery pack, charger and host computer, it includes the electric quantity measures the charging circuit and includes charging the measuring module, data handling module and data transmission module; the charging measurement module is connected with the data processing module, the battery pack and the charger, and the data transmission module is connected with the data processing module and the host;

the charging measurement module measures battery information of the battery pack and transmits the battery information to the data processing module through the system management bus, and the battery pack is charged according to the charging voltage transmitted by the charger and the charging state is controlled;

the data processing module performs analog-to-digital conversion on the battery information according to a preset resolution ratio and outputs serial port battery data to the data transmission module;

and the data transmission module converts the serial battery data into USB battery data and transmits the USB battery data to the host for display.

In the electric quantity measuring and charging circuit, the charging measuring module comprises a charging control unit, a charging access unit and a balance control unit; the charging control unit is connected with the charging path unit, the balance control unit, the data processing module and the battery pack; the charging path unit is connected with the charger, the balance control unit and the battery pack, and the balance control unit is connected with the battery pack;

the charging control unit measures battery information of the battery pack, transmits the battery information to the data processing module through a system management bus, and controls the on-off of a charging path in the charging path unit;

the charging path unit charges the battery pack by the charging voltage transmitted by the charger according to the on-off of the charging path and adjusts the charging state;

the balance control unit is used for shunting and balancing the current of each battery cell in the battery pack.

In the electric quantity measuring and charging circuit, the high-voltage excitation module comprises a charging control unit which comprises a battery pack manager, a first key, a second key, a first capacitor, a first resistor, a first thermistor, a second thermistor, a third thermistor, a fourth thermistor and a fifth thermistor;

the PB1 pin of the battery pack manager is grounded through a first capacitor; the pins VC4, VC3, VC2 and VC1 of the battery pack manager are in one-to-one connection with the

pins

5, 4, 3 and 2 of the battery pack; the SRP pin of the battery pack manager is connected with one end of the first resistor and the 1 st pin of the battery pack, and the 1 st pin of the battery pack is grounded; the SRN pin of the battery pack manager is connected with the other end of the first resistor and the charging path unit; the TS1 pin of the battery pack manager is grounded through the first thermistor, the TS2 pin of the battery pack manager is grounded through the second thermistor, the TS3 pin of the battery pack manager is grounded through the third thermistor, and the TS4 pin of the battery pack manager is grounded through the fourth thermistor; the PRES pin of the battery pack manager is grounded through the first key, and is also connected with the charging path unit; the DISP pin of the battery pack manager is grounded through the second key, the SMBD pin and the SMBC pin of the battery pack manager are both connected with the data transmission module, the PEN pin of the battery pack manager is connected with the BAT pin of the battery pack manager U1, and the BAT pin of the battery pack manager is connected with the balance control unit and the data processing module; the FUSE pin, the CHG pin, the PCHG pin, the VCC pin, the DSG pin and the PACK pin of the battery PACK manager are all connected with the charging path unit; the PTC pin of the battery pack manager is connected with the BAT pin of the battery pack manager through the fifth thermistor, and the NC pin and the VSS pin of the battery pack manager are both grounded.

In the electric quantity measuring and charging circuit, the charging control unit further comprises a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a second resistor, a third resistor, a fourth resistor and a fifth resistor;

a VC4 pin of the battery pack manager is connected with one end of a second capacitor and one end of a second resistor; a VC3 pin of the battery pack manager is connected with one end of the third capacitor, the other end of the second capacitor and one end of the third resistor; a VC2 pin of the battery pack manager is connected with one end of a fourth capacitor, the other end of the third capacitor and one end of a fourth resistor; a VC1 pin of the battery pack manager is connected with one end of the fifth capacitor, the other end of the fourth capacitor and one end of the fifth resistor; the other end of the second resistor, the other end of the third resistor, the other end of the fourth resistor and the other end of the fifth resistor are connected with the 5 th pin, the 4 th pin, the 3 rd pin and the 2 nd pin of the battery pack in a one-to-one mode.

In the electric quantity measuring and charging circuit, the charging control unit further comprises a sixth resistor and a first diode;

one end of the sixth resistor is connected with the cathode of the first diode and the PRES pin of the battery pack manager, the other end of the sixth resistor is connected with the charging path unit, and the anode of the first diode is grounded.

In the electric quantity measuring and charging circuit, the charging path unit comprises a protective tube, a charging interface, a third key, a first field effect tube, a second field effect tube, a third field effect tube, a fourth field effect tube, a fifth field effect tube, a sixth capacitor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor;

the 1 st pin of the charging interface is connected with the 2 nd pin of the charging interface and one end of a sixth capacitor, and the 1 st pin of the charging interface is also connected with the source electrode of a fourth field effect transistor, the source electrode of a third field effect transistor, one end of a third key and a PACK pin of a battery PACK manager; the 3 rd pin of the charging interface is connected with a PRES pin of the battery pack manager; the 4 th pin of the charging interface is connected with the 5 th pin of the charging interface, the other end of the sixth capacitor, the other end of the first resistor and the ground; the grid electrode of the fourth field effect transistor is connected with a charging ground, the drain electrode of the fourth field effect transistor is connected with the grid electrode of the third field effect transistor and the DSG pin of the battery pack manager, and the seventh resistor is connected between the grid electrode and the source electrode of the third field effect transistor; the drain electrode of the third field effect transistor is connected with the source electrode of the first field effect transistor, the source electrode of the second field effect transistor, one end of the eighth resistor and the VCC pin of the battery pack manager; the grid electrode of the first field effect transistor is connected with the other end of the eighth resistor and the PCHG pin of the battery pack manager; the drain electrode of the first field effect transistor is connected with the other end of the third key, the source electrode of the second field effect transistor, one end of the ninth resistor and one end of the protective tube; the grid electrode of the second field effect transistor is connected with the other end of the ninth resistor and the CHG pin of the battery pack manager, and the trigger end of the protective tube is connected with the drain electrode of the fifth field effect transistor; the grid electrode of the fifth field effect transistor is connected with one end of the tenth resistor, the balance control unit and the FUSE pin of the battery pack manager; and the source electrode of the fifth field effect transistor is connected with the other end of the tenth resistor and the ground, and the other end of the protective tube is connected with the balance control unit and the battery pack.

In the electric quantity measuring and charging circuit, the balance control unit comprises a battery cell protection chip, a second diode, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor and a thirteenth capacitor;

a VDD pin of the battery cell protection chip is connected with the anode of the second diode and the other end of the protective tube, the cathode of the second diode is connected with a BAT pin of the battery pack manager, a VC4 pin of the battery cell protection chip is connected with one end of a ninth capacitor and one end of a twelfth resistor, and a VC3 pin of the battery cell protection chip is connected with one end of a tenth capacitor, the other end of the ninth capacitor and one end of the thirteenth resistor; a VC2 pin of the battery cell protection chip is connected with one end of an eleventh capacitor, the other end of a tenth capacitor and one end of a fourteenth resistor; a VC1 pin of the battery cell protection chip is connected with one end of a twelfth capacitor, the other end of an eleventh capacitor and one end of a fifteenth resistor; the CD pin of the battery cell protection chip is grounded through a thirteenth capacitor, the OUT pin of the battery cell protection chip is connected with the FUSE pin of the battery pack manager and the grid electrode of a fifth field effect transistor, the other end of a twelfth resistor is connected with the 5 th pin of the battery pack, the other end of the thirteenth resistor is connected with the 4 th pin of the battery pack, the other end of the fourteenth resistor is connected with the 3 rd pin of the battery pack, the other end of the fifteenth resistor is connected with the 2 nd pin of the battery pack, and the VSS pin of the battery cell protection chip and the other end of the twelfth capacitor are both grounded.

In the electric quantity measuring and charging circuit, the data processing module comprises a single chip microcomputer, a voltage reducing tube, a first inductor, a third diode, a fourth diode, a first indicator light and a second indicator light;

the TO/P1.2 pin and the P1.3 pin of the single chip microcomputer are connected with the SMBC pin and the SMBD pin of the battery pack manager in a one-TO-one manner; a VCC pin of the singlechip is connected with a VOUT pin of the voltage reducing tube, a VIN pin of the voltage reducing tube is connected with a cathode of the third diode and a cathode of the fourth diode, an anode of the third diode is connected with a power supply end, an anode of the fourth diode is connected with a BAT pin of the battery pack manager, a P1.1 pin of the singlechip is connected with the power supply end through the first inductor, a P3.6/INT3 pin of the singlechip is connected with an anode of the first indicator lamp, a P3.5/INT3 pin of the singlechip is connected with an anode of the second indicator lamp, and a TxD/P3.1 pin and an RxD/P3.0 pin of the singlechip are both connected with the data transmission module; the GND pin of the single chip microcomputer, the negative electrode of the first indicator light and the negative electrode of the second indicator light are all grounded.

In the electric quantity measuring and charging circuit, the data transmission module comprises a USB-to-serial port chip, a USB interface, a seventh diode, a second inductor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor and a twentieth capacitor;

a V0_33 pin of the USB-to-serial port chip is grounded through an eighteenth capacitor, a VDD pin of the USB-to-serial port chip is grounded through a nineteenth capacitor, and a DP pin and a DM pin of the USB-to-serial port chip are connected with a 3 rd pin and a 2 nd pin of a USB interface in a one-to-one manner; the VDD pin of the USB-to-serial port chip is also connected with one end of a twentieth capacitor, one end of a second inductor and one end of a seventeenth capacitor, the other end of the second inductor is connected with one end of a sixteenth capacitor and the cathode of a seventh diode, the anode of the seventh diode is connected with the 1 st pin of a USB interface, and the TXD pin and the RXD pin of the USB-to-serial port chip are connected with the RxD/P3.0 pin and the TxD/P3.1 pin of the single chip in a one-to-one manner; GND of the USB-to-serial port chip, a 4 th pin of the USB interface, a 5 th pin of the USB interface J1, the other end of the sixteenth capacitor, the other end of the seventeenth capacitor and the other end of the twentieth capacitor are all grounded.

An electric quantity detection display system comprises a battery pack, a charger and a host computer, and also comprises an electric quantity measurement charging circuit; the electric quantity measuring and charging circuit is connected with the battery pack, the charger and the host;

the electric quantity measuring and charging circuit measures battery information of the battery pack, converts the format of the battery information and outputs the battery information to a display screen of the host computer for display; the electric quantity measuring and charging circuit is used for charging the battery pack according to the charging voltage transmitted by the charger.

Compared with the prior art, the utility model provides an electric quantity measurement charging circuit and electric quantity detection display system, electric quantity detection display system include group battery, charger, host computer and the electric quantity measurement charging circuit; the electric quantity measuring and charging circuit is connected with the battery pack, the charger and the host; the electric quantity measuring and charging circuit measures battery information of the battery pack, converts the format of the battery information and outputs the battery information to a display screen of the host computer for display; the electric quantity measuring and charging circuit is used for charging the battery pack according to the charging voltage transmitted by the charger. The battery information of the battery pack can be directly measured, and the problems that the existing battery electric quantity detection and display circuit can only detect the electric quantity and can not detect other battery information can be solved.

Drawings

Fig. 1 is a block diagram of the power detection display system provided by the present invention.

Fig. 2 is a circuit diagram of the charging measurement module provided by the present invention.

Fig. 3 is a circuit diagram of the data processing module provided by the present invention.

Fig. 4 is a circuit diagram of the data transmission module provided by the present invention.

Detailed Description

The utility model provides a power measurement charging circuit and power detection display system. In order to make the objects, technical solutions and effects of the present invention clearer and clearer, the following description of the present invention will refer to the accompanying drawings and illustrate embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the invention.

Referring to fig. 1 to fig. 3, an electric quantity detection display system according to an embodiment of the present invention includes an electric quantity measurement charging circuit 10, a battery pack 20, a charger 30, and a host 40; the electricity quantity measuring and charging circuit 10 is connected with the battery pack 20, the charger 30 and the host computer 40. The electric quantity measuring and charging circuit 10 measures battery information of the battery pack 20 (including available capacity, voltage, current, temperature and electric quantity ratio of the battery pack 20), performs format conversion (serial port to USB) on the battery information, and outputs the battery information to the display screen of the host 40 for display. The charge measurement charging circuit 10 also charges the battery pack 20 according to the charging voltage transmitted by the charger.

In this embodiment, the battery pack (such as a lithium ion battery pack or a lithium polymer battery pack) 20, in which 1, 2, 3, and 4 batteries are connected in series, is subjected to operations such as power monitoring, protection, and authentication; the battery information such as available capacity, voltage, current, temperature and electric quantity ratio of the battery pack can be directly measured through the electric quantity measuring and charging circuit 10, and the problems that the existing battery electric quantity detecting and displaying circuit can only detect electric quantity and can not detect other battery information can be solved. The electric quantity measuring and charging circuit 10 can be applied to other devices, such as mobile phones, computers, B-ultrasonic devices and other devices or systems which need to acquire battery information.

In this embodiment, the electric quantity measuring and charging circuit 10 includes a charging measuring module 11, a data processing module 12 and a data transmission module 13; the charging measurement module 11 is connected with the data processing module 12, the battery pack 20 and the charger 30, and the data transmission module 13 is connected with the data processing module 12 and the host 40.

The charging measurement module 11 measures battery information of the battery pack 20 and transmits the battery information to the data processing module 12 through a system management bus (SMBus), and charges the battery pack 20 according to the charging voltage transmitted by the charger and controls the charging state (for example, trickle charging at the initial stage, then large-current charging, and charging is prohibited after full charging); the data processing module 12 performs analog-to-digital conversion on the battery information according to a preset resolution (for example, 16 bit) and outputs serial battery data to the data transmission module 13, and the data transmission module 13 converts the serial battery data into USB battery data and transmits the USB battery data to the display screen of the host 40 for display.

Because the adopted ADC conversion is 16-bit, compared with 8-bit of the traditional singlechip, the precision of the singlechip is increased in geometric grade; the battery information can be updated once every 0.25 second, so that the transmission speed is increased; by adopting a system management bus (SMBus) for transmission, the problem that many computers do not have SMBus interfaces can be solved.

The charging measurement module 11 includes a charging control unit 111, a charging path unit 112, and a balance control unit 113; the charging control unit 111 is connected with the charging path unit 112, the balance control unit 113, the data processing module 12 and the battery pack 20; the charging path unit 112 connects the charger 30, the balance control unit 113, and the battery pack 20, and the balance control unit 113 connects the battery pack 20.

The charging control unit 111 measures battery information of the battery pack 20 and transmits the battery information to the data processing module 12 through a system management bus (SMBus), and controls the on/off of the charging path in the charging path unit 112. The charging path unit 112 charges the battery pack 20 with the charging voltage transmitted from the charger according to the on/off of the charging path and adjusts the charging state. The balance control unit 113 is configured to perform shunt balance on the currents of the battery cells in the battery pack.

With reference to fig. 2, the charging control unit 111 includes a battery pack manager U1, a first key S1, a second key S2, a first capacitor C1, a first resistor R1, a first thermistor RT1, a second thermistor RT2, a third thermistor RT3, a fourth thermistor RT4, and a fifth thermistor RT 5; the PB1 pin of the battery pack manager U1 is grounded through a first capacitor C1; the pins VC4, VC3, VC2 and VC1 of the battery pack manager U1 are in one-to-one connection with the

pins

5, 4, 3 and 2 of the battery pack 20; the SRP pin of the battery pack manager U1 is connected with one end of a first resistor R1 and the 1 st pin of the battery pack 20, and the 1 st pin of the battery pack 20 is grounded through a 0 omega resistor; the SRN pin of the battery pack manager U1 is connected with the other end of the first resistor R1 and the charging path unit 112; a TS1 pin of a battery pack manager U1 is grounded through a first thermistor RT1, a TS2 pin of a battery pack manager U1 is grounded through a second thermistor RT2, a TS3 pin of a battery pack manager U1 is grounded through a third thermistor RT3, and a TS4 pin of a battery pack manager U1 is grounded through a fourth thermistor RT 4; the PRES pin of the battery pack manager U1 is grounded through the first key S1, and the PRES pin is further connected to the charging path unit 112; the DISP pin of the battery pack manager U1 is grounded through a second key S2, the SMBD pin and the SMBC pin of the battery pack manager U1 are both connected with the data transmission module 12, the PEN pin of the battery pack manager U1 is connected with the BAT pin of the battery pack manager U1, and the BAT pin of the battery pack manager U1 is connected with the balance control unit 113 and the data processing module 12; the FUSE pin, the CHG pin, the PCHG pin, the VCC pin, the DSG pin, and the PACK pin of the battery PACK manager U1 are all connected to the charging path unit 112; the PTC pin of the battery pack manager U1 is connected with the BAT pin of the battery pack manager U1 through a fifth thermistor RT5, and the NC pin and the VSS pin of the battery pack manager U1 are both grounded.

The model of the battery pack manager U1 is preferably BQ40Z50, which can measure the available capacity, voltage, current, temperature and electric quantity ratio of the battery pack 20 and complete the recording of the data; whether the battery pack is connected or not and whether the battery pack is charged or not can be detected. The first capacitor C1 is a filtering energy storage capacitor of the PBI pin of the battery pack manager U1, and is used for supplying power to the U1 when the U1 is momentarily dead; the first resistor R1 is a charging current detection resistor with a resistance value of preferably 100 Ω, and the battery pack manager U1 can calculate the current charging current according to the voltages at its SRP pin and SRN pin and the resistance value of R1. The TS1 pin to the TS5 pin of the battery pack manager U1 detect the temperature through the corresponding thermistors, and the charging is stopped when the battery pack manager U1 overheats, so that the whole charging circuit can be protected. Acquiring the electric quantity of the battery pack 20 through a pin VC1 to a pin VC4 of the battery pack manager U1, and calculating the current available capacity, voltage, current, temperature (calculated according to a temperature value detected by a thermistor) and an electric quantity ratio; the available capacity, voltage, current, temperature and charge ratio are transmitted together as battery information (CLK _ battery, DATA _ battery) to the DATA processing module 12 via the system management bus (SMBus). The FUSE pin, CHG pin, PCHG pin, VCC pin, DSG pin, and PACK pin of the battery PACK manager U1 output corresponding control signals to control the on/off state of the charge path unit 112. When a fault is encountered, a first key S1 may be pressed to restart the battery pack manager U1.

Preferably, the charging control unit 111 further includes a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a fifth capacitor C5, a second resistor R2, a third resistor R3, a fourth resistor R4, and a fifth resistor R5; a VC4 pin of the battery pack manager U1 is connected with one end of a second capacitor C2 and one end of a second resistor R2; a VC3 pin of the battery pack manager U1 is connected with one end of a third capacitor C3, the other end of a second capacitor C2 and one end of a third resistor R3; a VC2 pin of the battery pack manager U1 is connected with one end of a fourth capacitor C4, the other end of the third capacitor C3 and one end of a fourth resistor R4; a VC1 pin of the battery pack manager U1 is connected with one end of a fifth capacitor C5, the other end of a fourth capacitor C4 and one end of a fifth resistor R5; the other end of the second resistor R2, the other end of the third resistor R3, the other end of the fourth resistor R4, and the other end of the fifth resistor R5 are connected to the 5 th, 4 th, 3 rd, and 2 nd pins of the battery pack 20 in a one-to-one manner.

The RC network formed by R5 and C5 is a filter circuit of a first battery cell, the RC network formed by R4 and C4 is a filter circuit of a second battery cell, the RC network formed by R3 and C3 is a filter circuit of a third battery cell, and the RC network formed by R2 and C2 is a filter circuit of a fourth battery cell. The voltage output by the battery pack 20 is filtered through the several RC networks, making the measurement of the battery pack manager U1 more accurate.

Preferably, the charging control unit 111 further includes a sixth resistor R6 and a first diode D1; one end of the sixth resistor R6 is connected to the cathode of the first diode D1 and the PRES pin of the battery pack manager U1, the other end of the sixth resistor R6 is connected to the charging path unit 112, and the anode of the first diode D1 is grounded. The sixth resistor R6 and the first diode D1 are used for electrostatic protection of the PRES pin.

The charging path unit 112 includes a fuse F1, a charging interface P1, a third key S3, a first fet Q1, a second fet Q2, a third fet Q3, a fourth fet Q4, a fifth fet Q5, a sixth capacitor C6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, and a tenth resistor R10; the 1 st pin of the charging interface P1 is connected with the 2 nd pin of the charging interface P1 and one end of a sixth capacitor C6, and the 1 st pin of the charging interface P1 is also connected with the source electrode of a fourth field effect transistor Q4, the source electrode of a third field effect transistor Q3, one end of a third key S3 and the PACK pin of a battery PACK manager U1; the 3 rd pin of the charging interface P1 is connected with the PRES pin of the battery pack manager U1 (or connected with the other end of the sixth resistor R6); the 4 th pin of the charging interface P1 is connected with the 5 th pin of the charging interface P1, the other end of the sixth capacitor C6, the other end of the first resistor R1 and the ground; the grid electrode of the fourth field effect transistor Q4 is connected with a charging ground CHGND, the drain electrode of the fourth field effect transistor Q4 is connected with the grid electrode of the third field effect transistor Q3 and a DSG pin of a battery pack manager U1, and the seventh resistor R7 is connected between the grid electrode and the source electrode of the third field effect transistor Q3; the drain electrode of the third field effect transistor Q3 is connected with the source electrode of the first field effect transistor Q1, the source electrode of the second field effect transistor Q2, one end of the eighth resistor R8 and the VCC pin of the battery pack manager U1; the grid electrode of the first field effect transistor Q1 is connected with the other end of the eighth resistor R8 and the PCHG pin of the battery pack manager U1; the drain electrode of the first field effect transistor Q1 is connected with the other end of the third key S3, the source electrode of the second field effect transistor Q2, one end of a ninth resistor R9 and one end of a protective tube F1; the grid electrode of the second field effect transistor Q2 is connected with the other end of the ninth resistor R9 and the CHG pin of the battery pack manager U1, and the trigger end of the protective tube F1 is connected with the drain electrode of the fifth field effect transistor Q5; a gate of the fifth field effect transistor Q5 is connected to one end of the tenth resistor R10, the balance control unit 113 and the FUSE pin of the battery pack manager U1; the source of the fifth field effect transistor Q5 is connected to the other end of the tenth resistor R10 and ground, and the other end of the fuse F1 is connected to the balance control unit 113 and the battery pack 20.

The model of the fuse tube F1 is preferably SFD-125A, the first field effect tube Q1 is a PMOS tube for controlling a trickle charge switch in the initial stage, the second field effect tube Q2 is an NMOS tube for controlling a large-current charge switch, the third field effect tube Q3 is an NMOS tube for controlling the charge forbidding, and the charging paths are formed by Q1 to Q3. The fourth field effect transistor Q4 is an NMOS transistor that prevents reverse insertion of the charger. The charging interface P1 is externally connected with a socket of a charger, and the 1 st pin and the 2 nd pin of the charging interface P1 are charging positive electrodes PACK +; the 4 th pin and the 5 th pin of the charging interface P1 are charging cathodes PACK-, which output charging voltage and charging current to charge the battery PACK 20. When the positive pole and the negative pole of the charger are reversed, the charging ground CHGND is connected with the positive pole of the charger (at the moment, the voltage on the PACK + is low), the Q4 causes the grid of the Q3 to be pulled down to be low level, and the Q3 is cut off to disconnect the charging path, so that the safety is ensured. The fifth field effect transistor Q5 is an NMOS transistor triggering the FUSE F1, and when the U2 detects an abnormality through the eighth pin or the battery pack manager U1, the FUSE pin outputs a high level to open the fifth field effect transistor Q5, thereby triggering the FUSE F1 to FUSE and disconnect the charging circuit.

Preferably, the charging path unit 112 further includes an eleventh resistor R11, a seventh capacitor C7, and an eighth capacitor C8; one end of the eleventh resistor R11 is connected with the drain of the first field effect transistor Q1; the other end of the eleventh resistor R11 is connected with the source electrode of the second field effect transistor Q2, one end of the seventh capacitor C7 and the other end of the third key S3; the other end of the seventh capacitor C7 is connected to the source of the first fet Q1 through the eighth capacitor C8. The eleventh resistor R11 is a current-limiting resistor during trickle charge of Q1; the C7 and C8 are used for protecting the field effect transistors Q1, Q2 and Q3 in case of accidents.

The balance control unit 113 includes a cell protection chip U2, a second diode D2, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a ninth capacitor C9, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, and a thirteenth capacitor C13; a VDD pin of the cell protection chip U2 is connected to an anode of the second diode D2 and the other end of the fuse F1, a cathode of the second diode D2 is connected to a BAT pin of the battery pack manager U1, a VC4 pin of the cell protection chip U2 is connected to one end of the ninth capacitor C9 and one end of the twelfth resistor R12, and a VC3 pin of the cell protection chip U2 is connected to one end of the tenth capacitor C10, the other end of the ninth capacitor C9 and one end of the thirteenth resistor R13; a VC2 pin of the cell protection chip U2 is connected with one end of an eleventh capacitor C11, the other end of a tenth capacitor C10 and one end of a fourteenth resistor R14; a VC1 pin of the cell protection chip U2 is connected with one end of a twelfth capacitor C12, the other end of an eleventh capacitor C11 and one end of a fifteenth resistor R15; the CD pin of the cell protection chip U2 is grounded through a thirteenth capacitor C13, the OUT pin of the cell protection chip U2 is connected with the FUSE pin of the battery pack manager U1 and the grid electrode of the fifth field effect transistor Q5, the other end of the twelfth resistor R12 is connected with the 5 th pin of the battery pack 20, the other end of the thirteenth resistor R13 is connected with the 4 th pin of the battery pack 20, the other end of the fourteenth resistor R14 is connected with the 3 rd pin of the battery pack 20, the other end of the fifteenth resistor R15 is connected with the 2 nd pin of the battery pack 20, and the VSS pin of the cell protection chip U2 and the other end of the twelfth capacitor C12 are both grounded.

Preferably, the model of the cell protection chip U2 is a second-level battery cell protection device of a BQ2947 series, and whether 4 cell voltages are within a set threshold value is detected correspondingly from a VC1 pin to a VC4 pin thereof, and if any one of the cell voltages exceeds or is lower than the threshold value, the OUT pin of the cell protection chip U2 outputs a corresponding level to control the fifth field-effect transistor Q5 to be turned on or off, that is, the charging current can be adjusted to balance the charging current of each cell until the voltage values of the 4 cell voltages are equal and within the threshold value. The RC network formed by R15 and C12 is a current shunt balancing circuit of a first cell, the RC network formed by R14 and C11 is a current shunt balancing circuit of a second cell, the RC network formed by R13 and C10 is a current shunt balancing circuit of a third cell, and the RC network formed by R12 and C9 is a current shunt balancing circuit of a fourth cell.

Referring to fig. 3, the data processing module 12 includes a single chip microcomputer U3, a voltage dropping tube U4, a first inductor L1, a third diode D3, a fourth diode D4, a first indicator light LD1, and a second indicator light LD 2; the TO/P1.2 pin and the P1.3 pin of the singlechip U3 are connected with the SMBC pin and the SMBD pin of the battery pack manager U1 in a one-TO-one manner; a VCC pin of the singlechip U3 is connected with a VOUT pin of the buck tube U4, a VIN pin of the buck tube U4 is connected with a cathode of the third diode D3 and a cathode of the fourth diode D4, an anode of the third diode D3 is connected with a power supply end (providing +19V power supply voltage), an anode of the fourth diode D4 is connected with a BAT pin of the battery pack manager U1, a P1.1 pin of the singlechip U3 is connected with the power supply end through a first inductor L1, a P3.6/INT3 pin of the singlechip U3 is connected with an anode of the first indicator lamp LD1, a P3.5/INT3 pin of the singlechip U3 is connected with an anode of the second indicator lamp LD2, and TxD/P3.1 pins and RxD/P3.0 pins of the singlechip U3 are both connected with the data transmission module 13; the GND pin of the singlechip U3, the negative electrode of the first indicator light LD1 and the negative electrode of the second indicator light LD2 are all grounded.

The type of the singlechip U3 is preferably STC15W402AS, the third diode D3 is used for preventing the reverse string of the supply voltage +19V, and the fourth diode D4 is used for preventing the reverse string of the BATTERY voltage BATTERY. U4 is a step-down tube for generating the working voltage (+ 5V) of the singlechip U3 after the supply voltage +19V or the BATTERY voltage BATTERY is reduced. The single chip microcomputer U3 and the battery pack manager U1 transmit battery information (CLK _ battery, DATA _ battery) through a system management bus (SMBus), and TO/P1.2 pins and P1.3 pins of the single chip microcomputer U3 are common IO ports and can simulate the working principle of the system management bus (SMBus) TO receive the battery information (CLK _ battery, DATA _ battery), so that the selection range of the single chip microcomputer is wide, and meanwhile, the cost of the low-cost single chip microcomputer cannot be increased. When the single chip microcomputer U3 detects that the battery is currently in a charging state, the single chip microcomputer U3 drives the first indicator lamp LD1 to emit yellow light; the second indicator light LD2 is driven to emit green light after the full-filling is detected.

The resolution of the ADC of the single chip microcomputer U3 is 16 bits, and compared with the 8 bits of the traditional single chip microcomputer, the single chip microcomputer has higher precision, so that the problem that the accuracy of electric quantity is influenced due to lower sampling precision can be solved; and the working speed is faster, so that the battery information can be updated once every 0.25 second, the transmitted data volume and data frequency are faster, and the floating of the electric quantity value is not increased when the instantaneous power consumption is very large.

Preferably, the data processing module 12 further includes a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a fifth diode D5, a sixth diode D6, a fourteenth capacitor C14, and a fifteenth capacitor C15; one end of the sixteenth resistor R16 is connected with the anode of the fifth diode D5 and the ground; the other end of the sixteenth resistor R16 is connected with the cathode of the fifth diode D5, one end of the seventeenth resistor R17, one end of the eighteenth resistor R18 and the SMBC pin of the battery pack manager U1; the other end of the seventeenth resistor R17 is connected with a VOUT pin of a voltage reducing tube U4, and the other end of the eighteenth resistor R18 is connected with a TO/P1.2 pin of the singlechip U3 and one end of a fourteenth capacitor C14; one end of the nineteenth resistor R19 is connected to the anode of the sixth diode D6 and ground; the other end of the nineteenth resistor R19 is connected with the cathode of the sixth diode D6, one end of the twentieth resistor R20, one end of the twenty-first resistor R21 and the SMBD pin of the battery pack manager U1; the other end of the twentieth resistor R20 is connected with a VOUT pin of the voltage reducing tube U4, the other end of the twenty-first resistor R21 is connected with a P1.3 pin of the singlechip U3 and one end of a fifteenth capacitor C15, and the other ends of the fourteenth capacitor C14 and the fifteenth capacitor C15 are grounded.

The fourteenth capacitor C14 is a filter capacitor of a TO/P1.2 pin of the singlechip U3, the eighteenth resistor R18 is a current-limiting resistor of the TO/P1.2 pin, the seventeenth resistor R17 is a pull-up resistor of the TO/P1.2 pin, and the sixteenth resistor R16 and the fifth diode D5 are an electrostatic protection network of the TO/P1.2 pin. The fifteenth capacitor C15 is a filter capacitor of a pin P1.3 of the singlechip U3, the twenty-first resistor R21 is a current-limiting resistor of the pin P1.3, the twentieth resistor R20 is a pull-up resistor of the pin P1.3, and the nineteenth resistor R19 and the sixth diode D6 are an electrostatic protection network of the pin P1.3.

Preferably, 2 capacitors connected in parallel can be further connected between the VIN pin of the buck tube U4 and the ground to filter and store energy at the input end of the buck tube U4; 2 capacitors connected in parallel are connected between the pin VOUT of the voltage reducing tube U4 and the ground to filter and store energy at the output end. And a capacitor is connected between the VCC pin of the singlechip U3 and the ground to filter the input working voltage + 5V. The TxD/P3.1 pin and the RxD/P3.0 pin of the single chip microcomputer U3 are respectively connected with the data transmission module 13 after passing through a resistor, and the 2 resistors are current limiting resistors on a serial port receiving and transmitting line.

Referring to fig. 4, the data transmission module 13 includes a USB to serial port chip U5, a USB interface J1, a seventh diode D7, a second inductor L2, a sixteenth capacitor C16, a seventeenth capacitor C17, an eighteenth capacitor C18, a nineteenth capacitor C19, and a twentieth capacitor C20; the V0_33 pin of the USB serial-to-serial port chip U5 is grounded through an eighteenth capacitor C18, the VDD pin of the USB serial-to-serial port chip U5 is grounded through a nineteenth capacitor C19, and the DP pin and the DM pin of the USB serial-to-serial port chip U5 are connected with the 3 rd pin and the 2 nd pin of the USB interface J1 in a one-to-one manner; the VDD pin of the USB-to-serial port chip U5 is further connected with one end of a twentieth capacitor C20, one end of a second inductor L2 and one end of a seventeenth capacitor C17, the other end of the second inductor L2 is connected with one end of a sixteenth capacitor C16 and the cathode of a seventh diode D7, the anode of the seventh diode D7 is connected with the 1 st pin of a USB interface J1, and the TXD pin and the RXD pin of the USB-to-serial port chip U5 are connected with the RxD/P3.0 pin and the TxD/P3.1 pin of the singlechip U3 in a one-to-one manner; the GND of the USB-to-serial port chip U5, the 4 th pin of the USB interface J1, the 5 th pin of the USB interface J1, the other end of the sixteenth capacitor C16, the other end of the seventeenth capacitor C17 and the other end of the twentieth capacitor C20 are all grounded.

The USB interface J1 is configured to implement data (i.e., battery information) transmission between the data transmission module and the host, and the USB to serial port chip U5 converts serial battery data (TX 0 and RX 0) output by the data processing module 12 into USB battery data (USB 1_ D + IN and USB1_ D-IN) and transmits the USB battery data to the display screen of the host 40 for display. The seventh diode D7 is used to prevent the voltage from being anti-series; the sixteenth capacitor C16, the second inductor L2 and the seventeenth capacitor C17 form a pi-shaped filter circuit for supplying power to a VDD pin of the USB-to-serial port chip U5; the twentieth capacitor C20 is a filter capacitor of a power supply pin 3 of the USB-to-serial port chip U5, C19 is a filter capacitor of a power supply pin 7 of the U5, and C18 is a filter capacitor of an internal LDO of the U5.

To sum up, in the electric quantity detection display system provided by the utility model, the battery information is measured through the battery pack manager, including the available capacity, voltage, current, temperature and electric quantity ratio of the battery pack; battery information is transmitted to the single chip microcomputer through the SMBus, and the single chip microcomputer converts serial battery data into USB battery data and then uploads the USB battery data to the host computer for display; the problem that a plurality of computers do not have SMBus interfaces at present is solved; the data is received by simulating the SMBus bus working principle through the common IO port of the single chip microcomputer, so that the selection range of the single chip microcomputer is wide, the cost can be reduced, and the single chip microcomputer is transmitted after being converted into a serial port through a USB, so that the reliability of data transmission is improved; the USB protocol is the most commonly used protocol at present, and the portability of the scheme is greatly improved. The battery information contains the key parameters of the battery, and the integrated chip also ensures the accuracy of the data; the detection of whether the battery is connected or not and the detection of whether the battery is charged or not are omitted, and the electric quantity measuring and charging circuit is simplified. The battery pack manager is also integrated with a temperature sensor, integrates two-stage safety protection strategies, basically covers the measures of battery safety protection, such as overvoltage, undervoltage, overcurrent, overload, overtemperature, overcharge and the like, can effectively monitor the state of the battery, and greatly improves the safety of the battery.

The division of the functional modules is only used for illustration, and in practical applications, the functions may be distributed by different functional modules according to needs, that is, the functions may be divided into different functional modules to complete all or part of the functions described above.

It should be understood that equivalent alterations and modifications can be made by those skilled in the art according to the technical solution of the present invention and the inventive concept thereof, and all such alterations and modifications should fall within the scope of the appended claims.

Claims

1. An electric quantity measuring and charging circuit is connected with a battery pack, a charger and a host, and is characterized by comprising a charging measuring module, a data processing module and a data transmission module; the charging measurement module is connected with the data processing module, the battery pack and the charger, and the data transmission module is connected with the data processing module and the host;

2. The electrical quantity measuring and charging circuit of claim 1, wherein the charging measuring module comprises a charging control unit, a charging path unit and a balance control unit; the charging control unit is connected with the charging path unit, the balance control unit, the data processing module and the battery pack; the charging path unit is connected with the charger, the balance control unit and the battery pack, and the balance control unit is connected with the battery pack;

3. The electrical quantity measuring and charging circuit of claim 2, wherein the charging control unit comprises a battery pack manager, a first key, a second key, a first capacitor, a first resistor, a first thermistor, a second thermistor, a third thermistor, a fourth thermistor and a fifth thermistor;

the PB1 pin of the battery pack manager is grounded through a first capacitor; the pins VC4, VC3, VC2 and VC1 of the battery pack manager are in one-to-one connection with the pins 5, 4, 3 and 2 of the battery pack; the SRP pin of the battery pack manager is connected with one end of the first resistor and the 1 st pin of the battery pack, and the 1 st pin of the battery pack is grounded; the SRN pin of the battery pack manager is connected with the other end of the first resistor and the charging path unit; the TS1 pin of the battery pack manager is grounded through the first thermistor, the TS2 pin of the battery pack manager is grounded through the second thermistor, the TS3 pin of the battery pack manager is grounded through the third thermistor, and the TS4 pin of the battery pack manager is grounded through the fourth thermistor; the PRES pin of the battery pack manager is grounded through the first key, and is also connected with the charging path unit; the DISP pin of the battery pack manager is grounded through the second key, the SMBD pin and the SMBC pin of the battery pack manager are both connected with the data transmission module, the PEN pin of the battery pack manager is connected with the BAT pin of the battery pack manager U1, and the BAT pin of the battery pack manager is connected with the balance control unit and the data processing module; the FUSE pin, the CHG pin, the PCHG pin, the VCC pin, the DSG pin and the PACK pin of the battery PACK manager are all connected with the charging path unit; the PTC pin of the battery pack manager is connected with the BAT pin of the battery pack manager through the fifth thermistor, and the NC pin and the VSS pin of the battery pack manager are both grounded.

4. The electrical quantity measuring and charging circuit of claim 3, wherein the charging control unit further comprises a second capacitor, a third capacitor, a fourth capacitor, a fifth capacitor, a second resistor, a third resistor, a fourth resistor, and a fifth resistor;

5. The electrical quantity measuring and charging circuit of claim 4, wherein the charging control unit further comprises a sixth resistor and a first diode;

6. The electric quantity measuring and charging circuit according to claim 4, wherein the charging path unit comprises a protective tube, a charging interface, a third key, a first field effect transistor, a second field effect transistor, a third field effect transistor, a fourth field effect transistor, a fifth field effect transistor, a sixth capacitor, a seventh resistor, an eighth resistor, a ninth resistor and a tenth resistor;

7. The electrical quantity measuring and charging circuit of claim 6, wherein the balance control unit comprises a cell protection chip, a second diode, a twelfth resistor, a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a ninth capacitor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, and a thirteenth capacitor;

8. The electricity quantity measuring and charging circuit of claim 7, wherein the data processing module comprises a single chip microcomputer, a voltage reducing tube, a first inductor, a third diode, a fourth diode, a first indicator light and a second indicator light;

9. The electrical quantity measuring and charging circuit of claim 8, wherein the data transmission module comprises a USB to serial port chip, a USB interface, a seventh diode, a second inductor, a sixteenth capacitor, a seventeenth capacitor, an eighteenth capacitor, a nineteenth capacitor and a twentieth capacitor;

10. An electric quantity detection display system, comprising a battery pack, a charger and a host computer, and further comprising an electric quantity measurement charging circuit according to any one of claims 1 to 9; the electric quantity measuring and charging circuit is connected with the battery pack, the charger and the host;