Electric quantity detection circuit and electronic device

Abstract

The utility model relates to the technical field of electric quantity detection, and discloses an electric quantity detection circuit and an electronic device, and the electric quantity detection circuit comprises a voltage dividing module, a voltage following module, a voltage detection module, a voltage comparison module and a display module. The voltage dividing module is used for dividing and filtering the output voltage of the battery to be detected to obtain a voltage to be detected and transmitting the voltage to be detected to the voltage detection module through the voltage following module; the voltage detection module is used for calculating the output voltage of the to-be-detected battery according to the to-be-detected voltage to judge the electric quantity of the battery; the voltage comparison module is used for comparing the to-be-measured voltage with a voltage threshold so as to output a level signal according to a comparison result; the display module is used for triggering different display states according to the level signal so as to indicate the electric quantity state of the to-be-tested battery. The electric quantity detection circuit can realize electric quantity detection with low output impedance and impedance matching in the pin of the single-chip microcomputer, so that a worker can conveniently and intuitively see that the electric quantity of the to-be-detected battery is too low on a product.

Description

Technical Field

[0001] This application relates to the field of power detection technology, and in particular to a power detection circuit and electronic device. Background Technology

[0002] When using a microcontroller to implement different functions, a battery pack is required to ensure that the microcontroller can perform these functions. The battery's charge level is related to its terminal voltage. As the battery is used, its charge gradually decreases, and its terminal voltage also drops. Therefore, the battery charge level needs to be monitored so that users can promptly detect low battery levels and replace the battery. Currently, the circuits used for charge detection in the industry have two main drawbacks: firstly, their power is too low, and voltage fluctuations occur when the load changes, which can also cause impedance mismatch with the microcontroller's internal impedance, affecting sampling accuracy; secondly, the high power consumption of the batteries reduces their lifespan. Utility Model Content

[0003] In view of this, embodiments of this application provide a power detection circuit and electronic device to solve the problems of high battery power consumption and impedance mismatch.

[0004] In a first aspect, embodiments of this application provide a power detection circuit, including: a voltage divider module, a voltage follower module, a voltage detection module, a voltage comparison module, and a display module;

[0005] The voltage divider module is connected to the battery under test and the voltage follower module, the voltage follower module is connected to the voltage detection module and the voltage comparison module, and the voltage comparison module is connected to the display module.

[0006] The voltage divider module is used to divide and filter the output voltage of the battery under test to obtain the voltage under test, and then transmits it to the voltage detection module through the voltage follower module.

[0007] The voltage detection module is used to calculate the output voltage of the battery under test based on the voltage to be tested, so as to determine the charge of the battery under test;

[0008] The voltage comparison module is used to compare the voltage to be measured with a voltage threshold, and output a level signal according to the comparison result;

[0009] The display module is used to trigger different display states according to the level signal to indicate the power status of the battery under test.

[0010] In a first possible embodiment of the first aspect, the power detection circuit further includes: a battery holder;

[0011] The battery under test is detachably mounted on the battery holder.

[0012] In a second possible embodiment of the first aspect, the voltage divider module includes a diode, a first voltage divider resistor, a second voltage divider resistor, and a first capacitor;

[0013] The anode of the diode is connected to the battery under test, the cathode of the diode is connected to the first end of the first voltage divider resistor, the second end of the first voltage divider resistor is connected to the first end of the second voltage divider resistor, the first end of the first capacitor is connected to the series node of the first voltage divider resistor and the second voltage divider resistor, and the second end of the first capacitor is connected to the second end of the second voltage divider resistor and grounded.

[0014] In a third possible embodiment of the first aspect, the voltage follower module includes a voltage follower;

[0015] The non-inverting input of the voltage follower is connected to the voltage divider module, the inverting input of the voltage follower is connected to the output, the power supply of the voltage follower is connected to the first power supply, the grounding terminal of the voltage follower is grounded, and the output of the voltage follower is connected to the input of the voltage detection module and the voltage comparison module respectively.

[0016] In a fourth possible embodiment of the first aspect, the voltage detection module includes a microcontroller;

[0017] The AD pin of the microcontroller is connected to the output of the voltage follower module.

[0018] In a fifth possible embodiment of the first aspect, the voltage comparison module includes a third voltage divider resistor, a fourth voltage divider resistor, and a voltage comparator;

[0019] The first end of the third voltage divider resistor is connected to the second power supply, the second end of the third voltage divider resistor is connected to the fourth voltage divider resistor, and the second end of the fourth voltage divider resistor is grounded.

[0020] The non-inverting input of the voltage comparator is connected to the series node of the third and fourth voltage divider resistors, the inverting input of the voltage comparator is connected to the output of the voltage follower module, and the output of the voltage comparator is connected to the display module.

[0021] In a sixth possible embodiment of the first aspect, the display module includes a fifth voltage divider resistor, a sixth voltage divider resistor, and an indicator light;

[0022] The first end of the fifth voltage divider resistor is connected to the third power supply, the second end of the fifth voltage divider resistor is connected to the first end of the sixth voltage divider resistor, the second end of the sixth voltage divider resistor is connected to the first end of the indicator light, and the second end of the indicator light is grounded.

[0023] The series connection of the fifth voltage divider resistor and the sixth voltage divider resistor is connected to the output terminal of the voltage comparison module.

[0024] In a seventh possible embodiment of the first aspect, the voltage comparison module is further configured to output a level signal of a first level state when the voltage to be measured is greater than the voltage threshold.

[0025] The display module is also used to be in a first display state when it receives a level signal of the first level state, so as to indicate that the battery under test has sufficient power;

[0026] The voltage comparison module is also used to output a level signal of a second level state when the voltage to be measured is less than the voltage threshold.

[0027] The display module is also configured to be in a second display state when it receives a level signal of the second level state, so as to indicate that the battery under test has insufficient power.

[0028] In an eighth possible embodiment of the first aspect, the power detection circuit further includes: a remote terminal;

[0029] The remote terminal is connected to the output of the voltage detection module and is used to display power information.

[0030] Secondly, embodiments of this application provide an electronic device including the aforementioned power detection circuit.

[0031] The embodiments of this application have the following beneficial effects:

[0032] This embodiment of a power detection circuit includes: a voltage divider module, a voltage follower module, a voltage detection module, a voltage comparison module, and a display module. The voltage divider module is connected to the battery under test and the voltage follower module, the voltage follower module is connected to the voltage detection module and the voltage comparison module, and the voltage comparison module is connected to the display module. The voltage divider module is used to divide and filter the output voltage of the battery under test to obtain the voltage to be measured, which is then transmitted to the voltage detection module via the voltage follower module. The voltage detection module is used to calculate the output voltage of the battery under test based on the voltage to be measured to determine the battery power. The voltage comparison module is used to compare the voltage to be measured with a voltage threshold and output a level signal based on the comparison result. The display module is used to trigger different display states based on the level signal to indicate the power status of the battery under test. This power detection circuit has a low output impedance, which avoids impedance matching problems with the microcontroller pins and prevents voltage fluctuations due to load changes. The addition of a display module allows operators to visually view the battery power status on the product. Attached Figure Description

[0033] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This paper shows a schematic diagram of a first structure of the power detection circuit according to an embodiment of the present application;

[0035] Figure 2 A second structural schematic diagram of the power detection circuit according to an embodiment of this application is shown;

[0036] Figure 3 A circuit diagram of a power detection circuit according to an embodiment of this application is shown.

[0037] Explanation of key component symbols:

[0038] 100 - Power detection circuit; 110 - Voltage divider module; 120 - Voltage follower module; 130 - Voltage detection module; 140 - Voltage comparison module; 150 - Display module; 160 - Battery under test; 170 - Remote terminal. Detailed Implementation

[0039] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0040] The components of the embodiments of this application described and illustrated in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0041] In the following text, the terms "comprising," "having," and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as primarily excluding the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more combinations thereof. Furthermore, the terms "first," "second," "third," etc., are used only for distinguishing descriptions and should not be construed as indicating or implying relative importance.

[0042] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0043] The following detailed description of some embodiments of this application is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0044] To address the issue that existing power detection circuits can easily cause impedance mismatch within the microcontroller, reducing battery life, this application provides a power detection circuit. The circuit obtains and filters the voltage to be measured through a voltage divider module. After impedance matching by a voltage follower module, one input voltage detection module calculates and outputs power information, while the other input voltage comparison module controls the display status based on the comparison result between the measured voltage and a voltage threshold, indicating whether the battery has sufficient power.

[0045] The following describes the power detection circuit using specific embodiments.

[0046] Figure 1 A schematic diagram of a power detection circuit 100 according to an embodiment of this application is shown. Exemplarily, the power detection circuit 100 includes a voltage divider module 110, a voltage follower module 120, a voltage detection module 130, a voltage comparison module 140, and a display module 150. The voltage divider module 110 is connected to the battery under test 160 and the voltage follower module 120, the voltage follower module 120 is connected to the voltage detection module 130 and the voltage comparison module 140, and the voltage comparison module 140 is connected to the display module 150.

[0047] In this embodiment, the voltage divider module 110 is used to divide and filter the output voltage of the battery under test 160 to obtain the voltage to be measured, which is then transmitted to the voltage detection module 130 via the voltage follower module 120. The voltage follower module 120, which transmits the voltage to be measured to the voltage detection module 130, has high input impedance and low output impedance, achieving optimal signal transmission and circuit performance. In the power detection circuit 100, when the voltage to be measured is transmitted from the voltage divider module 110 to the voltage detection module 130, if there is an impedance mismatch, the voltage to be measured will be reflected, leading to signal loss and distortion. By providing high input impedance and low output impedance, the voltage follower module 120 can reduce the reflection of the voltage to be measured, ensuring that the voltage to be measured can be effectively transmitted from the voltage divider module 110 to the voltage detection module 130.

[0048] In one embodiment, the voltage detection module 130 calculates the output voltage of the battery under test 160 based on the voltage to be measured, thereby determining the battery charge level. Exemplarily, the voltage detection module 130 calculates the output voltage of the battery under test 160 based on the voltage to be measured after voltage division and the voltage division ratio, and thus determines the battery charge level based on the output voltage. The voltage comparison module 140 compares the voltage to be measured with a voltage threshold, and outputs a level signal based on the comparison result. The level signal has different level states, and the display module 150 triggers different display states based on the different level states of the level signal to indicate the charge level of the battery under test 160.

[0049] In one embodiment, the voltage comparison module 140 is further configured to output a level signal of a first level state when the voltage to be measured is greater than a voltage threshold; the display module 150 is further configured to be in a first display state when receiving the level signal of the first level state, to indicate that the battery 160 under test has sufficient power. The voltage comparison module 140 is further configured to output a level signal of a second level state when the voltage to be measured is less than a voltage threshold; the display module 150 is further configured to be in a second display state when receiving the level signal of the second level state, to indicate that the battery 160 under test has insufficient power.

[0050] It is understood that the descriptions of "first" and "second" in the first and second level states mentioned above are merely to distinguish between high and low level signals generated under different conditions. Similarly, the descriptions of "first" and "second" in the first and second display states of the display module 150 are merely to distinguish that the display module 150 has different display states when indicating whether the battery under test 160 has sufficient or insufficient power.

[0051] In one embodiment, the power detection circuit 100 further includes a battery holder on which the battery under test 160 is detachably mounted. The battery holder includes multiple spring contacts for securing the battery under test 160 and is connected to the positive and negative terminals of the battery under test 160 to provide power to other electronic devices. It is understood that using a battery holder to secure the battery under test 160 facilitates battery replacement by staff and avoids data loss due to insufficient battery power and failure to replace the battery in time.

[0052] In another embodiment, such as Figure 2 As shown, the power detection circuit 100 also includes a remote terminal 170; the remote terminal 170 is connected to the second terminal of the voltage detection module 130, and is used to display the battery power information detected by the voltage detection module 130. Exemplarily, the remote terminal 170 includes, but is not limited to, devices such as remote monitoring terminals and displays.

[0053] The structure and operation of each component in the power detection circuit 100 are described below. Figure 3 A circuit diagram of a power detection circuit 100 according to an embodiment of this application is shown.

[0054] In one embodiment, the voltage divider module 110 includes a diode D1, a first voltage divider resistor R1, a second voltage divider resistor R2, and a first capacitor C1. The anode of diode D1 is connected to the battery under test 160, the cathode of diode D1 is connected to the first terminal of the first voltage divider resistor R1, the second terminal of the first voltage divider resistor R1 is connected to the first terminal of the second voltage divider resistor R2, the first terminal of the first capacitor C1 is connected to the series connection node of the first voltage divider resistor R1 and the second voltage divider resistor R2, the second terminal of the first capacitor C1 is connected to the second terminal of the second voltage divider resistor R2, and the parallel connection node of the first capacitor C1 and the second voltage divider resistor R2 is grounded to GND.

[0055] In this embodiment, diode D1 can limit any potential damage to the circuit by absorbing any voltage falling within the breakdown voltage range of diode D1, ensuring that the current flows only in the correct direction. The first voltage divider resistor R1 and the second voltage divider resistor R2 are mainly used to distribute the output voltage of the battery under test 160 to different voltage divider points in a certain proportion, while filtering out the AC component in the voltage.

[0056] In one embodiment, the voltage follower module 120 includes a voltage follower U1. The non-inverting input of the voltage follower U1 is connected to the voltage divider module 110, i.e., connected to the first terminal of the first capacitor C1. The inverting input of the voltage follower U1 is connected to the output. The power supply terminal of the voltage follower U1 is connected to the first power supply VCC1. The ground terminal of the voltage follower U1 is grounded to GND. The output of the voltage follower U1 is connected to the input terminals of the voltage detection module 130 and the voltage comparison module 140, respectively.

[0057] In an optional embodiment, the voltage follower module 120 may further include a second capacitor C2, wherein the power supply terminal of the voltage follower U1 is connected to the first terminal of the second capacitor C2, and the second terminal of the second capacitor C2 is grounded to GND. It is understood that the second capacitor C2 is used to improve the performance and stability of the power detection circuit 100 and reduce the impact of interference and noise on the power detection circuit 100.

[0058] In this embodiment, the voltage follower U1 includes, but is not limited to, an operational amplifier voltage follower. The input and output voltages of the operational amplifier voltage follower are both the voltage to be measured, and it does not provide any amplification function. On one hand, the operational amplifier voltage follower has the characteristics of high input impedance and low output impedance, enabling impedance transformation. Its output impedance approaches zero, ensuring that the output voltage is not affected by changes in load impedance. On the other hand, because the operational amplifier voltage follower has high input impedance, it does not draw power from the preceding circuitry, thus acting as an isolation buffer. This helps the voltage signal to be transmitted to the voltage detection module 130 without attenuation.

[0059] In one embodiment, the voltage detection module 130 includes a microcontroller U2; the AD pin of the microcontroller U2 is connected to the output of the voltage follower module 120, i.e., connected to the output of the voltage follower U1. Exemplarily, the AD converter inside the microcontroller U2 samples the voltage to be tested at a certain sampling frequency and converts the sampled voltage to be tested into a corresponding digital value. The microcontroller U2 is also used to determine the output voltage of the battery to be tested 160 based on the voltage division ratio of the first voltage divider resistor R1 and the second voltage divider resistor R2, and to determine the charge level of the battery to be tested 160 based on the relationship between the output voltage and the charge level. For example, when a lithium battery is fully charged, its output voltage is usually around 4.2V; at a higher charge level (e.g., 80%-100%), the output voltage is generally maintained at 4.0-4.2V; as the charge is consumed, when the output voltage drops to around 3.7V, the charge may be around 50% remaining; when the output voltage is below 3.0V, the lithium battery's charge is very low, and continued use may damage the battery.

[0060] In one embodiment, the voltage comparison module 140 includes a third voltage divider resistor R3, a fourth voltage divider resistor R4, and a voltage comparator U3. The first terminal of the third voltage divider resistor R3 is connected to the second power supply VCC2, the second terminal of the third voltage divider resistor R3 is connected to the fourth voltage divider resistor R4, and the second terminal of the fourth voltage divider resistor R4 is grounded to GND. The non-inverting input terminal of the voltage comparator U3 is connected to the series node of the third voltage divider resistor R3 and the fourth voltage divider resistor R4, the inverting input terminal of the voltage comparator U3 is connected to the output terminal of the voltage follower module 120, i.e., the output terminal of the voltage follower U1, and the output terminal of the voltage comparator U3 is connected to the display module 150.

[0061] In another embodiment, the display module 150 includes a fifth voltage divider resistor R5, a sixth voltage divider resistor R6, and an indicator LED; the first end of the fifth voltage divider resistor R5 is connected to the third power supply VCC3, the second end of the fifth voltage divider resistor R5 is connected to the first end of the sixth voltage divider resistor R6, the second end of the sixth voltage divider resistor R6 is connected to the first end of the indicator LED, and the second end of the indicator LED is grounded GND; the series connection node of the fifth voltage divider resistor R5 and the sixth voltage divider resistor R6 is connected to the output terminal of the voltage comparison module 140, that is, connected to the output terminal of the voltage comparator U3.

[0062] In this embodiment, the third voltage divider resistor R3 and the fourth voltage divider resistor R4 are used to divide the output voltage of the second power supply VCC2 to provide an input voltage to the voltage comparator U3. This input voltage serves as a voltage threshold for comparison with the voltage to be measured. The voltage comparator U3 compares the voltage threshold with the voltage to be measured and outputs voltage level signals of different levels, indicating different output voltages. When the voltage to be measured is less than the voltage threshold, the voltage comparator U3 outputs a second-level voltage level signal, which illuminates the indicator LED, indicating that the battery under test 160 has insufficient power. When the voltage to be measured is greater than the voltage threshold, the voltage comparator U3 outputs a first-level voltage level signal, which turns off the indicator LED, indicating that the battery under test has sufficient power.

[0063] It is understood that this application uses the first voltage divider resistor R1 and the second voltage divider resistor R2 to filter and obtain the voltage to be detected. After impedance matching through the voltage follower U1, it is input to the AD pin of the microcontroller U2. The voltage follower U1 has a large input impedance, which reduces the power consumption of the battery under test by the power detection circuit itself, thus reducing power consumption. The voltage follower U1 has a small output impedance, which can avoid impedance matching problems in the circuit. The voltage follower U1 has the function of isolating input and output, so that changes in load will not affect the voltage after voltage division, improving the accuracy of voltage detection. The AD pin of the microcontroller U2 detects the voltage under test after voltage division, calculates the output voltage of the battery under test 160, thereby determining the battery level, and displays the power information on devices such as remote display terminals and displays. At the same time, the output of the voltage follower U1 is connected to the voltage comparator U3. The voltage threshold is set through the third voltage divider resistor R3 and the fourth voltage divider resistor R4. When the battery level is low, the indicator LED lights up, and the low battery status can be seen intuitively on the product, realizing synchronous warnings for remote and local use to meet the different needs of different application scenarios.

[0064] This application also proposes an electronic device, which can be a power distribution device, a terminal device, or a control device, etc. Exemplarily, this electronic device includes the power detection circuit 100 from the above embodiments. Since this electronic device uses the above-described power detection circuit 100, it possesses all the advantages of the power detection circuit 100 described above. It is understood that the options in the above embodiments are also applicable to this embodiment, and therefore will not be described again here.

[0065] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application.

Claims

1. A power detection circuit, characterized in that, include: Voltage divider module, voltage follower module, voltage detection module, voltage comparison module, and display module; The voltage divider module is connected to the battery under test and the voltage follower module, the voltage follower module is connected to the voltage detection module and the voltage comparison module, and the voltage comparison module is connected to the display module. The voltage divider module is used to divide and filter the output voltage of the battery under test to obtain the voltage under test, and then transmits it to the voltage detection module through the voltage follower module. The voltage detection module is used to calculate the output voltage of the battery under test based on the voltage to be tested, so as to determine the charge of the battery under test; The voltage comparison module is used to compare the voltage to be measured with a voltage threshold, and output a level signal according to the comparison result; The display module is used to trigger different display states according to the level signal to indicate the power status of the battery under test.

2. The power detection circuit according to claim 1, characterized in that, Also includes: Battery holder; The battery under test is detachably mounted on the battery holder.

3. The power detection circuit according to claim 1, characterized in that, The voltage divider module includes a diode, a first voltage divider resistor, a second voltage divider resistor, and a first capacitor; The anode of the diode is connected to the battery under test, the cathode of the diode is connected to the first end of the first voltage divider resistor, the second end of the first voltage divider resistor is connected to the first end of the second voltage divider resistor, the first end of the first capacitor is connected to the series node of the first voltage divider resistor and the second voltage divider resistor, and the second end of the first capacitor is connected to the second end of the second voltage divider resistor and grounded.

4. The power detection circuit according to claim 1, characterized in that, The voltage follower module includes a voltage follower; The non-inverting input of the voltage follower is connected to the voltage divider module, the inverting input of the voltage follower is connected to the output, the power supply of the voltage follower is connected to the first power supply, the grounding terminal of the voltage follower is grounded, and the output of the voltage follower is connected to the input of the voltage detection module and the voltage comparison module respectively.

5. The power detection circuit according to claim 1, characterized in that, The voltage detection module includes a microcontroller; The AD pin of the microcontroller is connected to the output of the voltage follower module.

6. The power detection circuit according to claim 1, characterized in that, The voltage comparison module includes a third voltage divider resistor, a fourth voltage divider resistor, and a voltage comparator; The first end of the third voltage divider resistor is connected to the second power supply, the second end of the third voltage divider resistor is connected to the fourth voltage divider resistor, and the second end of the fourth voltage divider resistor is grounded. The non-inverting input of the voltage comparator is connected to the series node of the third and fourth voltage divider resistors, the inverting input of the voltage comparator is connected to the output of the voltage follower module, and the output of the voltage comparator is connected to the display module.

7. The power detection circuit according to claim 1, characterized in that, The display module includes a fifth voltage divider resistor, a sixth voltage divider resistor, and an indicator light; The first end of the fifth voltage divider resistor is connected to the third power supply, the second end of the fifth voltage divider resistor is connected to the first end of the sixth voltage divider resistor, the second end of the sixth voltage divider resistor is connected to the first end of the indicator light, and the second end of the indicator light is grounded. The series connection of the fifth voltage divider resistor and the sixth voltage divider resistor is connected to the output terminal of the voltage comparison module.

8. The power detection circuit according to claim 1, characterized in that, The voltage comparison module is also used to output a level signal of a first level state when the voltage to be measured is greater than the voltage threshold. The display module is also used to be in a first display state when it receives a level signal of the first level state, so as to indicate that the battery under test has sufficient power; The voltage comparison module is also used to output a level signal of a second level state when the voltage to be measured is less than the voltage threshold. The display module is also configured to be in a second display state when it receives a level signal of the second level state, so as to indicate that the battery under test has insufficient power.

9. The power detection circuit according to claim 1, characterized in that, Also includes: Remote terminal; The remote terminal is connected to the output of the voltage detection module and is used to display power information.

10. An electronic device, characterized in that, Includes the power detection circuit as described in any one of claims 1-9.

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