Low leakage battery pack series circuit with temperature and pressure measurement functions

Abstract

The present invention relates to a low leakage battery pack series circuit with temperature and pressure measuring functions, comprising a first battery pack, a second battery pack, a first pressure measuring module connected in series between the positive electrode of the first battery pack and a first input pin of a controller, a second pressure measuring module connected in series between the positive electrode of the second battery pack and the second input pin of the controller, a first temperature measuring module connected in series between the negative electrode of the first battery pack and a third input pin of the controller, and a second temperature measuring module connected in series between the negative electrode of the second battery pack and a fourth input pin of the controller, wherein a first switch controlled by the controller is connected in series in the first pressure measuring module, a second switch controlled by the controller is connected in series in the second pressure measuring module, and a third switch controlled by the controller is connected in series in the first temperature measuring module, and the controller controls the start or shut down of the first pressure measuring module, the second pressure measuring module, and the first temperature measuring module through the first switch, the second switch, and the third switch, respectively.

Description

Technical Field

[0001] The invention relates to a low-leakage battery pack series circuit with temperature and pressure measurement functions. Background Art

[0002] As the power of electric tools increases, the demand for voltage is also increasing. Electric tools with a rated voltage of 40V have gradually appeared, but the rated voltage of traditional battery packs is not that high. In order to adapt to electric tools with a rated voltage of 40V, the current solution is to use two 20V battery packs in series for power supply. However, this power supply mode cannot achieve fine control of the voltage and temperature of each battery pack, resulting in a generally short service life of the battery pack. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a low leakage battery pack series circuit with temperature and pressure measurement functions to overcome the technical problem that the current series battery packs generally have a short service life.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is: a low-leakage battery pack series circuit with temperature and pressure measurement functions, including a first battery pack, a second battery pack connected in series with the negative pole of the first battery pack, a first pressure measuring module connected in series between the positive pole of the first battery pack and the first input pin of the controller, a second pressure measuring module connected in series between the positive pole of the second battery pack and the second input pin of the controller, a first temperature measuring module connected in series between the negative pole of the first battery pack and the third input pin of the controller, and a second temperature measuring module connected in series between the negative pole of the second battery pack and the fourth input pin of the controller, the first pressure measuring module is connected in series with a first switch controlled by the controller, the second pressure measuring module is connected in series with a second switch controlled by the controller, and the first temperature measuring module is connected in series with a third switch controlled by the controller, and the controller controls the start or shutdown of the first pressure measuring module, the second pressure measuring module, and the first temperature measuring module through the first switch, the second switch, and the third switch respectively.

[0005] As a preferred solution, the first pressure measuring module includes a first voltage-dividing resistor and a second voltage-dividing resistor connected in series, the end of the first voltage-dividing resistor away from the second voltage-dividing resistor is connected to the positive pole of the first battery pack through a first switch, and the end of the second voltage-dividing resistor away from the first voltage-dividing resistor is grounded, the first input pin of the controller is connected between the first voltage-dividing resistor and the second voltage-dividing resistor, the first switch is a transistor, the source of the first switch is connected to the positive pole of the first battery pack, the drain is connected to the first voltage-dividing resistor, the gate is connected to the source of a step-down transistor, the drain of the step-down transistor is grounded, the gate is connected to the first output pin of the controller through a diode, and the positive pole of the diode is connected to the first output pin of the controller.

[0006] As a preferred solution, the second switch is a transistor, the second pressure measuring module includes a third voltage-dividing resistor connected in series between the second switch source and the second battery pack positive electrode and a fourth voltage-dividing resistor connected to the drain of the second switch, the other end of the fourth voltage-dividing resistor is grounded, the second input pin of the controller is connected in parallel with the fourth voltage-dividing resistor at the drain of the second switch, and the gate of the second switch is electrically connected to the second output pin of the controller.

[0007] As a preferred solution, the third switch is a transistor, the first temperature measurement module includes a first thermistor connected in series between the source of the third switch and the negative electrode of the first battery pack, the first thermistor is located in the first battery pack, the drain of the third switch is grounded through a fifth voltage-dividing resistor, the third input pin of the controller and the fifth voltage-dividing resistor are connected in parallel to the drain of the third switch, and the gate of the third switch is electrically connected to the third output pin of the controller.

[0008] As a preferred solution, the fourth temperature measurement module includes a second thermistor and a sixth voltage divider resistor connected in series, the second thermistor is located in the second battery pack and connected to the negative pole of the second battery pack, the end of the sixth voltage divider resistor away from the second thermistor is connected to a detection power supply, and the fourth output pin of the controller is connected between the second thermistor and the sixth voltage divider resistor.

[0009] The beneficial effects of the present invention are as follows: the present invention monitors the operating voltage and operating temperature of the first battery pack in real time through the first pressure measuring module and the first temperature measuring module, cuts off the power supply when the operating voltage and operating temperature do not meet the requirements, avoids excessive discharge of the first battery pack or the operating temperature exceeds the safe range, and ensures the service life of the first battery pack. Similarly, the present invention monitors the operating voltage and operating temperature of the second battery pack through the second pressure measuring module and the second temperature measuring module to ensure the service life of the second battery pack. Moreover, the present invention also controls the shutdown and startup of the first pressure measuring module, the first temperature measuring module and the second temperature measuring module through the first switch, the second switch and the third switch, thereby reducing the leakage current of the power tool when it is not working, greatly extending the battery life of the first battery pack and the second battery pack. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The specific embodiments of the present invention are further described in detail below with reference to the accompanying drawings, wherein:

[0011] Figure 1 is a schematic diagram of the circuit of the present invention;

[0012] Figure 2 It is a specific circuit diagram of the circuit of the present invention. DETAILED DESCRIPTION

[0013] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0014] like Figure 1 The low-leakage battery pack series circuit with temperature and pressure measurement functions shown in the figure includes a first battery pack BAT1, a second battery pack BAT2 connected in series with the negative electrode of the first battery pack BAT1, a first pressure measuring module connected in series between the positive electrode of the first battery pack BAT1 and the first input pin IN01 of the controller MCU, a second pressure measuring module connected in series between the positive electrode of the second battery pack BAT2 and the second input pin IN02 of the controller MCU, a first temperature measuring module connected in series between the negative electrode of the first battery pack BAT1 and the third input pin IN03 of the controller MCU, and a second temperature measuring module connected in series between the negative electrode of the second battery pack BAT2 and the fourth input pin IN04 of the controller MCU. The first pressure measuring module is connected in series with a first switch Q1 controlled by the controller MCU, the second pressure measuring module is connected in series with a second switch Q2 controlled by the controller MCU, and the first temperature measuring module is connected in series with a third switch Q3 controlled by the controller MCU. The controller MCU controls the activation or deactivation of the first pressure measuring module, the second pressure measuring module, and the first temperature measuring module through the first switch Q1, the second switch Q2, and the third switch Q3, respectively.

[0015] like Figure 2 As shown, in this embodiment, the first pressure measurement module includes a first voltage-dividing resistor R1 and a second voltage-dividing resistor R2 connected in series. The end of the first voltage-dividing resistor R1 away from the second voltage-dividing resistor R2 is connected to the positive electrode of the first battery pack BAT1 through a first switch Q1, and the end of the second voltage-dividing resistor R2 away from the first voltage-dividing resistor R1 is grounded (GND). The first input pin IN01 of the controller MCU is connected between the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. The first switch Q1 is a transistor. The source of the first switch Q1 is connected to the positive electrode of the first battery pack BAT1, the drain is connected to the first voltage-dividing resistor R1, the gate is connected to the source of a step-down transistor Q4, the drain of the step-down transistor Q4 is grounded, the gate is connected to the first output pin OUT01 of the controller MCU through a diode D1, and the anode of the diode D1 is connected to the first output pin OUT01 of the controller MCU.

[0016] The second switch Q2 is a transistor. The second pressure measurement module includes a third voltage-dividing resistor R3 connected in series between the source of the second switch Q2 and the positive electrode of the second battery pack BAT2, and a fourth voltage-dividing resistor R4 connected to the drain of the second switch Q2. The other end of the fourth voltage-dividing resistor R4 is grounded. The second input pin IN02 of the controller MCU is connected in parallel with the fourth voltage-dividing resistor R4 to the drain of the second switch Q2. The gate of the second switch Q2 is electrically connected to the second output pin OUT02 of the controller MCU.

[0017] The third switch Q3 is a transistor. The first temperature measurement module includes a first thermistor NTC1 connected in series between the source of the third switch Q3 and the negative electrode of the first battery pack BAT1. The first thermistor NTC1 is located in the first battery pack BAT1. The drain of the third switch Q3 is grounded via a fifth voltage-divider resistor R5. The third input pin INO3 of the controller MCU and the fifth voltage-divider resistor R5 are connected in parallel to the drain of the third switch Q3. The gate of the third switch Q3 is electrically connected to the third output pin OUT03 of the controller MCU.

[0018] The fourth temperature measurement module includes a second thermistor NTC2 and a sixth voltage-dividing resistor R6 connected in series. The second thermistor NTC2 is located in the second battery pack BAT2 and is connected to the negative electrode of the second battery pack BAT2. The end of the sixth voltage-dividing resistor R6 away from the second thermistor NTC2 is connected to a detection power supply V+. The fourth input pin IN04 of the controller MCU is connected between the second thermistor NTC2 and the sixth voltage-dividing resistor R6.

[0019] Preferably, the on / off detection of the power supply V+ is controlled by the controller MCU.

[0020] The working process of the present invention is as follows: Figure 1 and Figure 2 As shown, when the power tool is in the startup state, the first battery pack BAT1 and the second battery pack BAT2 supply power to the B+ pin of the controller MCU, and the controller MCU is in the running state. The controller MCU outputs a high level to the gate of the buck transistor Q4 through the first output pin OUT01, so that the buck transistor Q4 is turned on. After the buck transistor Q4 is turned on, the gate voltage of the first switch Q1 is pulled down, thereby turning on the first switch Q1. The positive electrode of the first battery pack BAT1 is grounded through the first voltage-dividing resistor R1 and the second voltage-dividing resistor R2. At this time, the positive electrode voltage of the second voltage-dividing resistor R2 is simultaneously input into the first input pin IN01 of the controller MCU, and the controller MCU obtains the operating voltage of the first battery pack BAT1 through calculation.

[0021] Similarly, the controller MCU outputs a high level to the gate of the second switch Q2 through the second output pin OUT02, so that the positive electrode of the second battery pack BAT2 is grounded through the third voltage-dividing resistor R3 and the fourth voltage-dividing resistor R4. At this time, the positive electrode voltage of the fourth voltage-dividing resistor R4 is simultaneously input into the second input pin IN02 of the controller MCU, and the controller MCU obtains the operating voltage of the second battery pack BAT2 through calculation.

[0022] When the controller MCU is running, it also outputs a high level at the gate of the third switch Q3 through the third output pin OUT03, causing the third switch Q3 to be turned on, thereby grounding the positive electrode of the second battery pack BAT2 through the first thermistor NTC1 and the fifth voltage-divider resistor R5. At this time, the positive electrode voltage of the fifth voltage-divider resistor R5 is simultaneously input to the third input pin IN03 of the controller MCU. The controller MCU calculates the resistance value and corresponding temperature of the first thermistor NTC1. Since the first thermistor NTC1 is set in the first battery pack BAT1, the temperature of the first thermistor NTC1 is the operating temperature of the first battery pack BAT1.

[0023] When the power tool is started, the detection power supply V+ will be powered. At this time, the detection power supply V+, the sixth voltage-dividing resistor R6, the second thermistor NTC2, and the negative electrode of the second battery pack BAT2 form a conductive circuit. At this time, the positive electrode voltage of the second thermistor NTC2 is simultaneously input into the fourth input pin IN04 of the controller MCU. The controller MCU calculates the resistance value of the second thermistor NTC2 and the corresponding temperature, i.e., the operating temperature of the second battery pack BAT2.

[0024] The controller MCU monitors the operating temperature and operating voltage of the first battery pack BAT1 and the second battery pack BAT2 respectively. When it finds that the operating voltage or operating temperature of any battery pack exceeds the normal range, it can control the power tool to stop working, thereby providing comprehensive protection for the first battery pack BAT1 and the second battery pack BAT2 connected in series, effectively ensuring the service life of each battery pack.

[0025] When the power tool is turned off, the controller MCU stops working due to power failure, so it cannot drive the first switch Q1, the second switch Q2 and the third switch Q3 to close. The first pressure measuring module, the second pressure measuring module and the first temperature measuring module are all in the disconnected state, and the first battery pack BAT1 and the second battery pack BAT2 will not generate leakage current. At the same time, when the power tool is turned off, the detection power supply V+ is also disconnected, and the second temperature measuring module is directly connected to the negative pole of the second battery pack BAT2, so it will not cause leakage of the first battery pack BAT1 or the second battery pack BAT2. In summary, the series circuit of the present invention has the function of individually detecting the operating temperature and operating voltage of each battery pack when the power tool is started, and also has the effect of extremely low leakage current when the power tool is turned off, which can effectively ensure the service life of each battery pack and extend the battery life.

[0026] The above embodiments are merely illustrative of the principles and effects of the present invention, as well as some embodiments of its application, and are not intended to limit the present invention. It should be noted that a person skilled in the art can make several modifications and improvements without departing from the creative concept of the present invention, and these all fall within the scope of protection of the present invention.

Claims

1. A low leakage battery pack series circuit with temperature and pressure measurement functions, characterized in that: The invention comprises a first battery pack, a second battery pack connected in series to the negative electrode of the first battery pack, a first pressure measuring module connected in series between the positive electrode of the first battery pack and a first input pin of a controller, a second pressure measuring module connected in series between the positive electrode of the second battery pack and a second input pin of the controller, a first temperature measuring module connected in series between the negative electrode of the first battery pack and a third input pin of the controller, and a second temperature measuring module connected in series between the negative electrode of the second battery pack and a fourth input pin of the controller, wherein the first pressure measuring module is connected in series with a first switch controlled by the controller, the second pressure measuring module is connected in series with a second switch controlled by the controller, and the first temperature measuring module is connected in series with a third switch controlled by the controller, and the controller controls the start or shut down of the first pressure measuring module, the second pressure measuring module and the first temperature measuring module through the first switch, the second switch and the third switch respectively; The first pressure measuring module comprises a first voltage-dividing resistor and a second voltage-dividing resistor connected in series with each other, one end of the first voltage-dividing resistor away from the second voltage-dividing resistor is connected to the positive electrode of the first battery pack through a first switch, and one end of the second voltage-dividing resistor away from the first voltage-dividing resistor is grounded, the first input pin of the controller is connected between the first voltage-dividing resistor and the second voltage-dividing resistor, the first switch is a transistor, the source of the first switch is connected to the positive electrode of the first battery pack, the drain is connected to the first voltage-dividing resistor, the gate is connected to the source of a step-down transistor, the drain of the step-down transistor is grounded, the gate is connected to the first output pin of the controller through a diode, and the positive electrode of the diode is connected to the first output pin of the controller; The second switch is a triode, the second pressure measuring module includes a third voltage-dividing resistor connected in series between the source of the second switch and the positive electrode of the second battery pack and a fourth voltage-dividing resistor connected to the drain of the second switch, the other end of the fourth voltage-dividing resistor is grounded, the second input pin of the controller is connected in parallel with the fourth voltage-dividing resistor to the drain of the second switch, and the gate of the second switch is electrically connected to the second output pin of the controller; The third switch is a triode, the first temperature measurement module includes a first thermistor connected in series between the source of the third switch and the negative electrode of the first battery pack, the first thermistor is located in the first battery pack, the drain of the third switch is grounded through a fifth voltage-dividing resistor, the third input pin of the controller is connected in parallel with the fifth voltage-dividing resistor at the drain of the third switch, and the gate of the third switch is electrically connected to the third output pin of the controller.

2. The low leakage battery pack series circuit with temperature and pressure measurement functions according to claim 1, characterized in that: The fourth temperature measurement module includes a second thermistor and a sixth voltage-dividing resistor connected in series, the second thermistor is located in the second battery pack and connected to the negative electrode of the second battery pack, the end of the sixth voltage-dividing resistor away from the second thermistor is connected to a detection power supply, and the fourth output pin of the controller is connected between the second thermistor and the sixth voltage-dividing resistor.

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