Electricity meter correction circuit

Abstract

The utility model provides a kind of electric meter correction circuit, comprising: power supply loop;Buck series branch;And voltage compensation branch;Wherein, the buck series branch is made of multiple corresponding same rated current buck diode of successive connection, and including the diode two-end node formed based on multiple buck diode, the voltage compensation branch includes light emitting diode, series compensation resistance group and switch group, the series compensation resistance group is made of multiple successive connection compensation resistance, and the switch group includes multiple adjusting switch connected with each the compensation resistance one by one;The first end of the light emitting diode is connected with the power supply negative pole, the second end of the light emitting diode is connected with the first end of the series compensation resistance group, and the second end of the series compensation resistance group is connected with any diode two-end node of buck series branch has.Node. The utility model at least improves electric quantity display accuracy.

Description

Technical Field

[0001] This utility model relates to circuit technology, and in particular to a power meter correction circuit. Background Technology

[0002] In power equipment such as electric forklifts, site patrol vehicles, and portable emergency equipment, the battery is the core power source, and the accurate display of its remaining power directly determines the equipment's range assessment, usage scheduling, and safe operation and maintenance.

[0003] Traditional power equipment generally uses lead-acid batteries (referred to as lead batteries), which have the advantages of low cost and adaptability to overcharge and over-discharge. The corresponding power meter circuit design is also based on the voltage characteristics of lead batteries to match parameters, ensuring that the power display is consistent with the actual remaining power.

[0004] With the maturity of lithium battery technology, its advantages of high energy density (about 3 times that of lead batteries), long cycle life (about 2-3 times that of lead batteries), and lightweight are becoming increasingly prominent. In order to improve the range and portability of power equipment, more and more scenarios are replacing traditional lead batteries with lithium batteries (for example, including 36V, 48V, 60V, 72V and 96V lithium iron phosphate batteries and ternary lithium batteries). However, the voltage characteristics of lithium batteries and lead batteries cause the original lead battery power meters to display inaccurately, which has become a key obstacle to battery replacement and upgrading.

[0005] Therefore, there is an urgent need to provide a power meter correction circuit that can improve the accuracy of power display in corresponding battery replacement scenarios. Utility Model Content

[0006] Based on the above problems, this utility model is proposed to provide a power meter correction circuit that overcomes or at least partially solves the above problems.

[0007] According to one aspect of the present invention, a power meter correction circuit is provided, comprising: A power supply circuit that connects to the negative terminal of the battery module. A step-down series branch connected in series in the power supply circuit; and A voltage compensation branch connected in parallel with the step-down series branch; In this circuit, the step-down input terminal of the step-down series branch is connected to the negative terminal of the power supply, the step-down output terminal is connected to the first terminal of the power meter, and the second terminal of the power meter is connected to the negative terminal of the power supply. The step-down series branch consists of multiple step-down diodes connected in series with the same rated current, and includes diode end nodes formed by the multiple step-down diodes. The voltage compensation branch includes a light-emitting diode, a series compensation resistor group, and a switch group. The series compensation resistor group consists of multiple compensation resistors connected in series, and the switch group includes multiple adjustment switches connected to each compensation resistor. The first terminal of the light-emitting diode is connected to the negative terminal of the power supply, the second terminal of the light-emitting diode is connected to the first terminal of the series compensation resistor group, and the second terminal of the series compensation resistor group is connected to any diode end node in the step-down series branch.

[0008] Optionally, in the circuit according to the present invention, each step-down diode in the step-down series branch corresponds to the same rated current.

[0009] Optionally, in the circuit according to the present invention, the rated current is 10A, the forward voltage drop of each step-down diode is 0.7V, and the total voltage drop of the step-down series branch is the sum of the forward voltage drops of each step-down diode.

[0010] Optionally, in the circuit according to the present invention, the number of step-down diodes is nine, which are arranged in series as the first diode, the second diode, the third diode, the fourth diode, the fifth diode, the sixth diode, the seventh diode, the eighth diode, and the ninth diode. The number of nodes at both ends of the diode formed by the nine buck diodes is 10.

[0011] Optionally, in the circuit according to the present invention, the number of compensation resistors is four, namely a first resistor, a second resistor, a third resistor, and a fourth resistor. The first end of the first resistor is connected to the second end of the light-emitting diode, and the second end is connected to the diode end node formed by the fourth and fifth diodes. The first end of the second resistor is connected to the second end of the light-emitting diode, and the second end is connected to the diode end node formed by the fifth and sixth diodes. The first end of the second resistor of the third resistor is connected to the second end of the light-emitting diode, and the second end is connected to the diode end node formed by the sixth and seventh diodes. The first end of the second resistor of the third resistor is connected to the second end of the light-emitting diode, and the second end is connected to the diode end node formed by the seventh and eighth diodes.

[0012] Optionally, in the circuit according to this invention, the resistance value of each supplementary resistor is the same.

[0013] Optionally, in the circuit according to the present invention, the resistance value of the compensation resistor is in the range of 50Ω-200Ω.

[0014] Optionally, in the circuit according to the present invention, the compensation resistor is connected to the two ends of the diode by means of soldering an insulated wire to the pin of the corresponding step-down diode.

[0015] Optionally, in the circuit according to this invention, the regulating switch is a single-pole single-throw mechanical switch.

[0016] Optionally, in the circuit according to the present invention, the power meter includes an analog power meter or a digital power meter.

[0017] According to the solution of this utility model, the problem of inaccurate display of the original power meter after the lead-acid battery of the power equipment is replaced with a lithium battery is solved. It significantly improves the accuracy and adaptability of the power display under different battery replacement scenarios. By stepping down the voltage of the lithium battery to match the lead-acid meter, the electric vehicle's meter can display the power normally. Specifically, this can be reflected in the following aspects: 1. In terms of voltage characteristic adaptation, the step-down series branch achieves basic adaptation of lithium battery voltage to the design voltage of the original lead-acid battery power meter: This branch is composed of multiple step-down diodes with the same rated current connected in series. By utilizing the fixed forward voltage drop of the diodes, the total step-down value can be precisely controlled by adjusting the number of series diodes. At the same time, the design of the nodes at both ends of the diodes reserves a voltage adjustment interface for subsequent precise compensation, avoiding the defects of traditional fixed resistor step-down circuits that can only adapt at a single point and cannot cover the entire discharge range, thus laying the foundation for accurate power display across the entire voltage range. 2. In terms of dynamic voltage compensation, the voltage compensation branch achieves accurate correction of the power display during the full discharge cycle of the lithium battery through a flexible and adjustable compensation mechanism. The series compensation resistor group is composed of multiple compensation resistors connected in series. With the adjustment switch corresponding to each resistor, the total resistance value of the compensation resistors connected to the circuit can be changed by switching the switch combination. In addition, the addition of the light-emitting diode not only serves as a conduction indicator of the compensation circuit, but its fixed forward voltage drop can also further assist in fine-tuning the voltage and avoid display deviation caused by over-compensation. 3. In terms of scenario adaptability and flexibility, the circuit achieves compatibility with multiple battery specifications through modular design. The number of diodes in the step-down series branch can be flexibly adjusted according to the lithium battery voltage level, and the switch combination in the voltage compensation branch can be accurately adapted to the sampling sensitivity of the power meter of different devices. At the same time, the compensation accuracy can be adjusted through the compensation switch combination. When replacing the 11.1V lithium battery pack in portable emergency devices, only 2-3 step-down diodes and a small number of compensation resistors are needed to meet the requirements. In addition, the circuit has the advantages of high reliability and low power consumption: the step-down diodes use the same rated current specification to ensure the stability of the current in the series branch and avoid component damage caused by uneven current; the compensation resistor and switch are both selected from industrial-grade components, which can withstand the harsh working conditions such as vibration of power equipment and temperature and humidity changes; at the same time, the entire correction circuit only consumes a small amount of current when the power meter is working and will not increase the power loss of the lithium battery, thus ensuring the device's endurance. Attached Figure Description

[0018] Figure 1 A module division diagram of the power meter correction circuit according to the present invention is shown; Figure 2 The circuit structure diagram of the power meter correction circuit of this utility model is shown. Detailed Implementation

[0019] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0020] To address the problems existing in the prior art, the inventors have proposed the solution of this utility model. One embodiment of this utility model provides a power meter correction circuit. Figure 1 A module division diagram of the power meter correction circuit according to the present invention is shown, as follows: Figure 1 As shown, the power meter correction circuit of this utility model may specifically include a battery module, a step-down series branch, and a voltage compensation branch.

[0021] It can be explained that, Figure 2 The circuit structure diagram of the power meter correction circuit of this utility model is shown, as follows: Figure 2 As shown, in this utility model, the step-down input terminal of the step-down series branch is connected to the negative terminal of the power supply, the step-down output terminal is connected to the first terminal of the power meter, and the second terminal of the power meter is connected to the negative terminal of the power supply. The step-down series branch is composed of multiple step-down diodes with the same rated current connected in series and includes diode end nodes formed by multiple step-down diodes. The voltage compensation branch includes a light-emitting diode Q1, a series compensation resistor group, and a switch group. The series compensation resistor group is composed of multiple compensation resistors connected in series. The switch group includes multiple adjustment switches connected to each compensation resistor. The first terminal of the light-emitting diode Q1 is connected to the negative terminal of the power supply, the second terminal of the light-emitting diode Q1 is connected to the first terminal of the series compensation resistor group, and the second terminal of the series compensation resistor group is connected to any of the diode end nodes in the step-down series branch.

[0022] For example, in this embodiment, the overall power meter correction circuit includes three core parts: a power supply circuit connected to the positive and negative terminals of the battery module (i.e., the replaced lithium battery), a step-down series branch connected in series in the power supply circuit, and a voltage compensation branch connected in parallel with the step-down series branch. The connection relationship, composition, and circuit principle of each part are as follows: 1. The power supply circuit is the basic path for the entire correction circuit and the power meter to obtain working power. It is directly connected to the positive and negative terminals of the battery module's power supply. It can transmit the electrical energy output by the lithium battery to the step-down series branch, the voltage compensation branch, and the power meter, providing current support for the normal operation of each component. It can be said that the setting of this circuit ensures that the correction circuit can form a complete current path with the lithium battery, avoiding the failure of the correction function due to the lack of a power supply path. It is a prerequisite for realizing the correction of the power meter display, and fundamentally guarantees the implementation of the subsequent step-down and compensation functions. 2. The step-down series branch is connected in series in the power supply circuit. It is the core structure for achieving initial voltage adaptation of the lithium battery to the original power meter. Its specific connection relationship and working principle are as follows: (1) The step-down input terminal of the step-down series branch is connected to the positive power supply of the battery module, the step-down output terminal is connected to the first terminal of the power meter, and the second terminal of the power meter is directly connected to the negative power supply of the battery module, forming the basic signal transmission path of lithium battery, step-down series branch, power meter and lithium battery. (2) This branch consists of multiple step-down diodes connected in series with the same rated current. Based on these series-connected step-down diodes, nodes are naturally formed at both ends of the diodes (i.e., the connection point of two adjacent step-down diodes, the input node of the first step-down diode, and the output node of the last step-down diode). From the perspective of circuit principle, each step-down diode will generate a fixed forward voltage drop when it is turned on. After multiple diodes are connected in series, the total voltage drop is the sum of the forward voltage drops of each diode. Since the output voltage of the lithium battery is usually higher than the matching voltage of the original lead-acid battery (for example, the full-charge voltage of a 48V lithium battery may be significantly higher than that of a 48V lead-acid battery), the output voltage of the lithium battery can be reduced to a voltage range closer to that of the original lead-acid battery through the series step-down of this branch. This provides the original power meter with a basic voltage signal that meets its design range, and initially solves the problem of the initial display deviation of the power meter caused by the excessively high lithium battery voltage. It also avoids display distortion or damage to the power meter components caused by the voltage exceeding the range of the power meter. 3. The parallel connection of the voltage compensation branch and the voltage reduction series branch is a key structure for achieving precise phased correction, addressing the difference in voltage variation patterns between lithium batteries and lead-acid batteries during discharge. Its specific connection relationship, composition, and principle are as follows: (1) The voltage compensation branch includes a light-emitting diode Q1, a series compensation resistor group and a switch group; wherein, the series compensation resistor group is composed of multiple compensation resistors connected in series, and the switch group includes multiple adjustment switches connected to each compensation resistor; the first end of the light-emitting diode Q1 is connected to the negative terminal of the power supply of the battery module, the second end of the light-emitting diode Q1 is connected to the first end of the series compensation resistor group, and the second end of the series compensation resistor group can be connected to any two-terminal node of the diode in the step-down series branch, forming a compensation current path for the lithium battery, the two-terminal node of the diode in the step-down series branch, the series compensation resistor group, the light-emitting diode Q1, and the lithium battery. (2) The voltage drop curve of lithium battery during discharge is different from that of lead-acid battery (for example, the voltage drop of lithium battery is steeper and the voltage fluctuation of different discharge stages is more obvious). The fixed voltage drop of the series step-down branch alone cannot adapt to the voltage deviation of the lithium battery throughout the entire discharge cycle. However, the voltage compensation branch can achieve precise compensation in stages by connecting the two ends of the diode of the series step-down branch (different nodes correspond to different voltage values ​​after step-down, reflecting the voltage state of the lithium battery in different discharge stages). That is, when the lithium battery is in a certain discharge stage, the second end of the series compensation resistor group is connected to the two ends of the diode corresponding to that stage. By controlling the opening and closing of the corresponding adjustment switch in the control switch group, the appropriate compensation resistor is selected to be connected. The voltage division effect of the compensation resistor is used to adjust the current of the compensation branch, thereby fine-tuning the total voltage signal across the power meter so that the voltage signal received by the power meter is completely matched with the actual remaining power of the lithium battery in that stage, thus completely solving the problem of "inaccurate display of different discharge stages".

[0023] In addition, it can be noted that the LED Q1 in the voltage compensation branch also serves as an indicator of the working status. That is, when the compensation branch is conducting, the LED Q1 lights up, informing the user that the current correction circuit is in an effective compensation state. If the LED Q1 does not light up, it can prompt the user that the compensation branch is not working properly and that the switch or connection status needs to be checked, so as to avoid the user misjudging the power due to compensation failure, and further improve the reliability of power display and safety of use.

[0024] In summary, this utility model ensures power supply through a power supply circuit, initially adjusts the lithium battery voltage to the original range of the power meter using a step-down series branch, and then performs precise voltage correction for different discharge stages of the lithium battery through a voltage compensation branch. The three work together to comprehensively solve the problem of inaccurate power meter display after replacing lead-acid batteries with lithium batteries, from basic adaptation to precise compensation. This ensures that the power meter can accurately and stably reflect the remaining power of the lithium battery, improving the ease of use and operational safety of the power equipment.

[0025] Furthermore, in this embodiment, each step-down diode in the step-down series branch corresponds to the same rated current.

[0026] For example, in this embodiment, it is clear that each step-down diode in the step-down series branch corresponds to the same rated current. That is, all step-down diodes constituting the step-down series branch have the same maximum current specification that can be passed for a long time, and there is no situation where some diodes have high rated current and some have low rated current.

[0027] From a circuit logic perspective, the buck series branch, connected in series in the power supply circuit, must carry the entire operating current transmitted from the lithium battery to the power meter. If the rated currents of the buck diodes are different, when the operating current of the power equipment fluctuates (e.g., during equipment startup or high-load operation), the diode with the smaller rated current may burn out due to the current exceeding its carrying capacity, causing the buck series branch to be interrupted. This, in turn, causes the power meter to lose the appropriate voltage signal, resulting in display failure or severe deviation. This solution, however, limits the rated current of all buck diodes to the same value, ensuring consistent current carrying capacity for each diode, avoiding localized overload damage due to differences in component parameters, and guaranteeing long-term stable operation of the buck series branch.

[0028] Furthermore, in this embodiment, the rated current is 10A, the forward voltage drop of each step-down diode is 0.7V, and the total voltage drop of the step-down series branch is the sum of the forward voltage drops of each step-down diode.

[0029] For example, in this embodiment, the current drawn by most power equipment (e.g., electric vehicles, forklifts) is typically between 5A and 8A. A rated current of 10A can completely cover this range, preventing the step-down diode from burning out due to excessive current during high-load operation (e.g., climbing hills, heavy-duty work). This ensures reliable conduction of the step-down series branch under all operating conditions. Furthermore, from a voltage matching logic perspective, the voltage difference between lithium batteries and lead-acid batteries is one of the core reasons for inaccurate power meter readings (e.g., a 48V lead-acid battery has a full-charge voltage of approximately 53V, while a lithium battery of the same specification has a full-charge voltage of approximately 58V). Each step-down diode... The fixed forward voltage drop of the diodes (0.7V) allows the total voltage drop to be accurately calculated using "number of diodes × 0.7V" (for example, the total voltage drop of 9 diodes is 6.3V, 58V - 6.3V ≈ 51.7V, which is close to the full-charge voltage range of a lead-acid battery). This enables the lithium battery voltage to be precisely adjusted to the original design range of the power meter, avoiding initial display deviations caused by unclear voltage drops (such as excessive voltage drop causing the power meter to show low charge, or insufficient voltage drop causing the power meter to show full charge and overload). This solves the problem of inaccurate display from the perspective of voltage adaptation accuracy. At the same time, the fixed forward voltage drop parameter also facilitates component selection during mass production and reduces the difficulty of circuit design.

[0030] Furthermore, in this embodiment, the number of step-down diodes is nine, which are arranged in series as first diode Q1, second diode Q2, third diode Q3, fourth diode Q4, fifth diode Q5, sixth diode Q6, seventh diode Q7, eighth diode Q8 and ninth diode Q9; wherein, the number of diode terminals formed by the nine step-down diodes is ten.

[0031] For example, in this embodiment, from the perspective of voltage adaptation requirements, considering the forward voltage drop of 0.7V for each step-down diode, the total voltage drop of the 9 diodes is 6.3V. This value can accurately match the voltage difference of most 48V power equipment when switching from lead-acid to lithium batteries (a fully charged lithium battery is about 58V, a fully charged lead-acid battery is about 53V, 58V-6.3V≈51.7V, which is within the normal operating voltage range of lead-acid batteries). No additional adjustment to the number of diodes is needed to adapt to mainstream power equipment, improving the versatility of the solution. Furthermore, from the perspective of voltage compensation requirements, the nodes at both ends of the 10 diodes (including the 9...) The diode's eight adjacent connection points (first input node, last output node) correspond to the voltage values ​​of different discharge stages of the lithium battery. For example, the first node (closest to the positive terminal of the lithium battery) corresponds to the voltage of the lithium battery at full charge, the last node (closest to the power meter) corresponds to the voltage of the lithium battery at low charge, and the middle node corresponds to the voltage of transition stages such as half charge and medium low charge. This provides multiple accurate voltage sampling points, enabling the compensation branch to correct the voltage deviation of the lithium battery in stages throughout the entire discharge cycle. This avoids the problem of inaccurate display and failure to compensate for some discharge stages due to insufficient sampling points, thus improving the comprehensiveness of the correction.

[0032] Furthermore, in this embodiment, the number of compensation resistors is four: a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4. The first resistor R1 has its first end connected to the second end of the light-emitting diode Q1, and its second end connected to the diode node formed by the fourth diode Q4 and the fifth diode Q5. The second resistor R2 has its first end connected to the second end of the light-emitting diode Q1, and its second end connected to the diode node formed by the fifth diode Q5 and the sixth diode Q6. The second resistor R3 has its first end connected to the second end of the light-emitting diode Q1, and its second end connected to the diode node formed by the sixth diode Q6 and the seventh diode Q7. The second resistor R4 has its first end connected to the second end of the light-emitting diode Q1, and its second end connected to the diode node formed by the seventh diode Q7 and the eighth diode Q8. For example, in this embodiment, from the perspective of lithium battery discharge characteristics, the nodes formed by the fourth diode Q4 and the fifth diode Q5, and the nodes formed by the fifth diode Q5 and the sixth diode Q6, correspond to the "half-charge stage" and the "medium-discharge stage" of the lithium battery, respectively. These two stages are the most frequently encountered operating conditions in the use of power equipment, and also the stages where inaccurate power display has the greatest impact on users (for example, a deviation in the half-charge stage display may cause users to misjudge the remaining working time). This utility model connects four compensation resistors specifically to these two key nodes, which can achieve accurate compensation for the core discharge stages. For example, when the lithium battery is in the half-charge stage, the first resistor R1 is connected by controlling the switch group, and the voltage signal of the power meter is finely adjusted by the voltage division effect of the resistor to match the actual power in the half-charge state; when it is in the medium-discharge stage, the second or third resistor R3 is connected to correct the voltage deviation in this stage. This "key node + corresponding resistor" design not only avoids the waste of resources caused by indiscriminate connection of compensation resistors, but also focuses on the core user scenarios, ensuring accurate power display in commonly used discharge stages, and effectively solving the practical pain points after "lead-acid to lithium battery" power equipment.

[0033] Furthermore, in this embodiment, the resistance value of each supplementary resistor is the same, and the resistance value of the compensation resistor is within the corresponding resistance range of 50Ω-200Ω.

[0034] For example, in this embodiment, the voltage compensation branch selects the connected compensation resistors by controlling the on / off state of the switch group to adjust the compensation amount. If the resistance values ​​of the compensation resistors are different, the corresponding compensation amount for each resistor needs to be memorized (e.g., resistor A corresponds to 0.2V compensation, resistor B corresponds to 0.3V compensation), which is complex and prone to compensation deviation due to memorization errors. However, if all compensation resistors have the same resistance value, the total compensation amount can be directly calculated using the "number of connected resistors" (e.g., connecting one resistor corresponds to 0.2V compensation, connecting two resistors corresponds to 0.4V compensation), greatly simplifying the compensation control logic. Simultaneously, the resistance value of the compensation resistors must be compatible with the output voltage of the lithium battery and the operating current of the voltage compensation branch: if the resistance value is less than 50Ω, it will lead to excessive current in the compensation branch (according to Ohm's law I=U / R, when the voltage is fixed, the higher the resistance, the lower the current). A large current (if the resistance is too small, it may burn out the LED Q1 or the compensation resistor, causing circuit failure. If the resistance value is greater than 200Ω, the current in the compensation branch will be too small, resulting in weak compensation that cannot effectively correct the voltage deviation of the power meter and thus failing to provide compensation. Setting a resistance value range of 50Ω-200Ω ensures that the current in the compensation branch is within a safe range (under most lithium battery voltages, the current corresponding to this resistance value is between 10mA and 50mA, which meets the safe operating current of the LED Q1 and the resistor), avoiding overload damage to components, and also providing sufficient compensation (achieving the common compensation requirement of 0.2V-0.6V through current voltage division), so that the voltage signal of the power meter accurately matches the actual capacity of the lithium battery, balancing circuit safety and correction effectiveness, and solving the problem of compensation failure or safety hazards caused by improper resistance value.

[0035] Furthermore, in this embodiment, the compensation resistor is connected to the two ends of the diode by welding an insulated wire to the pin of the corresponding step-down diode, the adjustment switch is a single-pole single-throw mechanical switch, and the power meter is an analog power meter or a digital power meter.

[0036] For example, in this embodiment, the compensation resistor is fixed to the pins of the step-down diode via an insulated wire using a welding process, thereby achieving electrical connection with the two ends of the diode. From the perspective of connection reliability, power equipment (e.g., electric vehicles, forklifts) will generate continuous vibration or bumps during operation. If the compensation resistor and diode nodes are connected by a plug-in connection, poor contact can easily occur due to vibration, causing the compensation branch to be interrupted and resulting in inaccurate power display. The welding connection can form a strong metal bond, avoiding loosening of the connection due to vibration and ensuring stable electrical contact. In addition, from the perspective of circuit safety, the insulated wire can prevent short circuits with other metal components after the wire sheath is damaged, avoiding current leakage or circuit failure. Meanwhile, soldering wires to the diode pins ensures precise connection between the two diode nodes (the pins are directly related to the node voltage), avoiding sampling voltage errors caused by connection position deviations and ensuring that the voltage signal obtained by the compensation branch accurately reflects the lithium battery discharge state. The use of a single-pole single-throw mechanical switch (non-electronic switch) with only "on" and "off" operating states also avoids compensation deviations caused by switch malfunctions, ensuring accurate power display while improving circuit usability and maintainability. Furthermore, the power meter can include pointer-type meters that indicate power through pointer deflection, as well as digital meters that display power digitally, thus increasing its versatility.

[0037] In summary, this utility model solves the problem of inaccurate display of the original power meter after replacing the lead-acid battery with a lithium battery in power equipment, and significantly improves the accuracy and adaptability of the power display in different battery replacement scenarios. Specifically, this can be reflected in the following aspects: 1. In terms of voltage characteristic adaptation, the step-down series branch achieves basic adaptation of lithium battery voltage to the design voltage of the original lead-acid battery power meter: This branch is composed of multiple step-down diodes with the same rated current connected in series. By utilizing the fixed forward voltage drop of the diodes, the total step-down value can be precisely controlled by adjusting the number of series diodes. At the same time, the design of the nodes at both ends of the diodes reserves a voltage adjustment interface for subsequent precise compensation, avoiding the defects of traditional fixed resistor step-down circuits that can only adapt at a single point and cannot cover the entire discharge range, thus laying the foundation for accurate power display across the entire voltage range. 2. In terms of dynamic voltage compensation, the voltage compensation branch achieves accurate correction of the power display during the full discharge cycle of the lithium battery through a flexible and adjustable compensation mechanism. The series compensation resistor group is composed of multiple compensation resistors connected in series. With the adjustment switch corresponding to each resistor, the total resistance value of the compensation resistors connected to the circuit can be changed by switching the switch combination. In addition, the addition of the light-emitting diode Q1 not only serves as a conduction indicator of the compensation circuit, but its fixed forward voltage drop can also further assist in fine-tuning the voltage and avoid display deviation caused by over-compensation. 3. In terms of scenario adaptability and flexibility, the circuit achieves compatibility with multiple battery specifications through modular design. The number of diodes in the step-down series branch can be flexibly adjusted according to the lithium battery voltage level, and the switch combination in the voltage compensation branch can be accurately adapted to the sampling sensitivity of the power meter of different devices. At the same time, the compensation accuracy can be adjusted through the compensation switch combination. When replacing the 11.1V lithium battery pack in portable emergency devices, only 2-3 step-down diodes and a small number of compensation resistors are needed to meet the requirements. In addition, the circuit has the advantages of high reliability and low power consumption: the step-down diodes use the same rated current specification to ensure the stability of the current in the series branch and avoid component damage caused by uneven current; the compensation resistor and switch are both selected from industrial-grade components, which can withstand the harsh working conditions such as vibration of power equipment and temperature and humidity changes; at the same time, the entire correction circuit only consumes a small amount of current when the power meter is working and will not increase the power loss of the lithium battery, thus ensuring the device's endurance.

[0038] In the specification provided herein, the algorithms and displays are not inherently related to any particular computer, virtual system, or other device. Various general-purpose systems can also be used with the examples of this invention. The required structure for constructing such a system is apparent from the above description. Furthermore, this invention is not directed to any particular programming language. It should be understood that the contents of this invention described herein can be implemented using various programming languages, and the above description of specific languages ​​is for the purpose of disclosing preferred embodiments of this invention.

[0039] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the present invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0040] Similarly, it should be understood that, in order to simplify this disclosure and aid in understanding one or more of the various aspects of the invention, in the description of exemplary embodiments of the invention above, various features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof.

[0041] Those skilled in the art will understand that modules, units, or components of the devices disclosed in the examples herein can be arranged in the devices described in this embodiment, or alternatively, can be located in one or more devices different from the devices in this example. The modules in the foregoing examples can be combined into a single module or, in addition, can be divided into multiple sub-modules.

[0042] Those skilled in the art will understand that the modules in the device of the embodiment can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiment can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components.

[0043] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are meant to be within the scope of this invention and form different embodiments.

[0044] Furthermore, some of the embodiments described herein are methods or combinations of method elements that can be implemented by a processor of a computer system or by other means of performing the functions. Therefore, a processor having the necessary instructions for implementing the methods or method elements forms means for implementing the methods or method elements. Moreover, the elements described herein in the apparatus embodiments are examples of means for implementing the functions performed by elements for the purposes of implementing this invention.

[0045] As used herein, unless otherwise specified, the use of ordinal numbers such as “first,” “second,” “third,” etc., to describe ordinary objects merely indicates different instances of similar objects and is not intended to imply that the objects being described must have a given order in time, space, ordering, or any other manner.

[0046] Although the present invention has been described with reference to a limited number of embodiments, those skilled in the art will understand from the foregoing description that other embodiments can be conceived within the scope of the present invention described herein. Furthermore, it should be noted that the language used in this specification has been chosen primarily for readability and instructional purposes, and not for the purpose of interpreting or limiting the subject matter of the present invention.

Claims

1. A power meter correction circuit, characterized in that, include: A power supply circuit that connects to the negative terminal of the battery module. The step-down series branch connected in series in the power supply circuit; and A voltage compensation branch connected in parallel with the step-down series branch; In this circuit, the step-down input terminal of the step-down series branch is connected to the negative terminal of the power supply, the step-down output terminal is connected to the first terminal of the power meter, and the second terminal of the power meter is connected to the negative terminal of the power supply. The step-down series branch consists of multiple step-down diodes connected in series with the same rated current, and includes diode end nodes formed by the multiple step-down diodes. The voltage compensation branch includes a light-emitting diode, a series compensation resistor group, and a switch group. The series compensation resistor group consists of multiple compensation resistors connected in series, and the switch group includes multiple adjustment switches connected to each compensation resistor. The first terminal of the light-emitting diode is connected to the negative terminal of the power supply, the second terminal of the light-emitting diode is connected to the first terminal of the series compensation resistor group, and the second terminal of the series compensation resistor group is connected to any diode end node in the step-down series branch.

2. The power meter correction circuit according to claim 1, characterized in that, Each step-down diode in the step-down series branch corresponds to the same rated current.

3. The power meter correction circuit according to claim 2, characterized in that, The rated current is 10A, the forward voltage drop of each step-down diode is 0.7V, and the total voltage drop of the step-down series branch is the sum of the forward voltage drops of each step-down diode.

4. The power meter correction circuit according to claim 2, characterized in that, The number of step-down diodes is nine, which are connected in series as the first diode, second diode, third diode, fourth diode, fifth diode, sixth diode, seventh diode, eighth diode, and ninth diode; The number of nodes at both ends of the diode formed by the nine buck diodes is 10.

5. The power meter correction circuit according to claim 4, characterized in that, The number of compensation resistors is four, namely a first resistor, a second resistor, a third resistor, and a fourth resistor. The first resistor is connected to the second end of the light-emitting diode (LED) and the second end of the first resistor is connected to the two-end node of the diode formed by the fourth and fifth diodes. The first resistor is connected to the second end of the LED and the second end of the second resistor is connected to the two-end node of the diode formed by the fifth and sixth diodes. The second resistor of the third resistor is connected to the second end of the LED and the second end of the second resistor is connected to the two-end node of the diode formed by the sixth and seventh diodes. The second resistor of the third resistor is connected to the second end of the LED and the second end of the second resistor is connected to the two-end node of the diode formed by the seventh and eighth diodes.

6. The power meter correction circuit according to claim 1 or 5, characterized in that, Each supplementary resistor has the same resistance value.

7. The power meter correction circuit according to claim 6, characterized in that, The resistance value of the compensation resistor is within the range of 50Ω-200Ω.

8. The power meter correction circuit according to claim 1, characterized in that, The compensation resistor is connected to the two ends of the diode by soldering an insulated wire to the pin of the corresponding step-down diode.

9. The power meter correction circuit according to claim 1, characterized in that, The regulating switch is a single-pole single-throw mechanical switch.

10. The power meter correction circuit according to claim 1, characterized in that, The power meter may be an analog power meter or a digital power meter.

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