Conversion circuit for converting lithium battery into dry battery

Abstract

The invention provides a conversion circuit for converting a lithium battery into a dry battery. The conversion circuit comprises a battery cell voltage sampling module, a load current sampling module, an output voltage feedback module and a power management module, two input ends of the power management module are respectively connected with reference voltage and feedback voltage, an output end of the cell voltage sampling module is connected with the reference voltage, an output end of the output voltage feedback module is connected with the feedback voltage, and an output end of the load current sampling module is connected with one of the reference voltage and the feedback voltage. The load current sampling module is used for outputting internal resistance compensation current in direct proportion to load current. According to the conversion circuit, the output voltage can be reduced along with the reduction of the battery voltage and reduced along with the increase of the load current, and the output curve can completely fit the voltage characteristics of the dry battery.

Description

Technical Field

[0001] The invention belongs to the field of batteries, and in particular relates to a conversion circuit for converting lithium batteries into dry batteries. Background Art

[0002] Traditional alkaline batteries, also called dry batteries, have a wide range of applications, good discharge curves and higher energy density. However, their disadvantages are also very obvious. Alkaline batteries are disposable batteries, which will cause serious pollution to the environment after use. In addition, if they are left for a long time, they will cause chemical raw materials to leak due to moisture oxidation and other factors, resulting in damage to electronic products. Lithium batteries are light in weight, stable in chemical properties, can be repeatedly charged and discharged, and can also be used in conjunction with components to achieve diversified electronic applications such as power reminders and charging reminders.

[0003] Dry batteries have high energy density and are widely used. They can provide more stable power supply and longer service life, so it is necessary to simulate dry batteries. However, the existing lithium battery to dry battery structure all has a step-type output voltage, which cannot truly fit the dry battery discharge curve and cannot achieve linear changes in output voltage to battery voltage and load current. There are also conversion circuits that introduce MCU architecture, which have large circuit area and complex structure, which is not conducive to system integration. Summary of the invention

[0004] The object of the present invention is to provide a conversion circuit for converting a lithium battery into a dry cell, so that the discharge curve of the output voltage can fit the voltage characteristics of the dry cell.

[0005] In order to achieve the above-mentioned purpose, the present invention provides a conversion circuit for converting a lithium battery to a dry cell, comprising a discharge module connected to a cell of the lithium battery, the discharge module comprising a cell voltage sampling module, a load current sampling module, an output voltage feedback module, and a power management module; two input ends of the power management module are respectively connected to a reference voltage and a feedback voltage, the output end of the cell voltage sampling module is connected to the reference voltage, the output end of the output voltage feedback module is connected to the feedback voltage, the output end of the load current sampling module is connected to one of the reference voltage and the feedback voltage, and the load current sampling module is used to output an internal resistance compensation current that is proportional to the load current.

[0006] The cell voltage sampling module includes a resistor voltage-dividing structure whose input end is connected to the cell voltage; and / or the output voltage feedback module includes a second resistor voltage-dividing structure whose input end is connected to the output voltage of the discharge module.

[0007] The load current sampling module comprises a current sampling amplifier and a current sampling switch tube connected to the output end of the current sampling amplifier.

[0008] The output end of the load current sampling module is connected to the reference voltage; the positive phase voltage input end of the current sampling amplifier is connected to the sampling current and the compensation resistor at the same time, and the other end of the compensation resistor is grounded to obtain the voltage drop of the sampling current on the compensation resistor, and the sampling current is obtained by sampling the load current; the negative phase voltage input end of the current sampling amplifier is connected to one end of the fourth resistor and the low voltage side of the current sampling switch tube, and the other end of the fourth resistor is grounded, the gate of the current sampling switch tube is connected to the input end of the current sampling amplifier, and the high voltage side of the current sampling switch tube is connected to the reference voltage.

[0009] The output end of the load current sampling module is connected to the feedback voltage; the reverse voltage input end of the current sampling amplifier is connected to the sampling current and the compensation resistor at the same time, and the other end of the compensation resistor is connected to the cell voltage of the lithium battery, so that the reverse voltage input end obtains the cell voltage of the lithium battery minus the voltage drop of the sampling current on the compensation resistor, and the sampling current is obtained by sampling the load current; the positive phase voltage input end of the current sampling amplifier is connected to one end of the fourth resistor and the high voltage side of the current sampling switch tube, the other end of the fourth resistor is connected to the cell voltage of the lithium battery, the gate of the current sampling switch tube is connected to the input end of the current sampling amplifier, and the low voltage side of the current sampling switch tube is connected to the feedback voltage.

[0010] The compensation resistor is external or internal.

[0011] The power management module adopts a traditional buck step-down structure, which includes an error amplifier, a driving module, a group of parallel buck circuit switch tubes, and a filter circuit connected in sequence.

[0012] One of the reference voltage and the feedback voltage is connected to a current regulating module, and the current regulating module is used to provide a fixed regulating current.

[0013] The reference voltage is connected to a reference voltage clamping module, and the reference voltage clamping module is used to clamp the reference voltage within a threshold voltage range.

[0014] The conversion circuit for converting lithium batteries to dry batteries also includes a charging module connected to the battery cells of the lithium batteries, and the charging module is used to charge the battery cells of the lithium batteries.

[0015] The conversion circuit of the lithium battery to the dry cell battery of the present invention sets a cell voltage sampling module in the discharge module to realize that the output voltage decreases as the battery voltage decreases, and sets a load current sampling module to provide an internal resistance supplementary current to realize that the output voltage decreases as the load current increases. Therefore, the discharge curve of the output voltage can completely fit the voltage characteristics of the dry cell battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The system block diagram of the conversion circuit of the lithium battery to dry cell of the present invention.

[0017] Figure 2 1 is a system block diagram of a discharge module of a lithium battery to dry cell conversion circuit according to a first embodiment of the present invention.

[0018] Figure 3 4 is a circuit diagram of a discharge module of a lithium battery to dry cell conversion circuit according to a first embodiment of the present invention.

[0019] Figure 4 4 is a system block diagram of a discharge module of a lithium battery to dry cell conversion circuit according to a second embodiment of the present invention.

[0020] Figure 5 4 is a circuit diagram of a discharge module of a lithium battery to dry cell conversion circuit according to a second embodiment of the present invention.

[0021] Figure 6 4 is a system block diagram of a discharge module of a lithium battery to dry cell conversion circuit according to a third embodiment of the present invention.

[0022] Figure 7 4 is a circuit diagram of a discharge module of a lithium battery to dry cell conversion circuit according to a third embodiment of the present invention.

[0023] Fig. 8A and Figure 8B It is a curve comparison diagram of the discharge test results of AA batteries and AAA batteries and the fitting results of the conversion circuit of the lithium battery to dry battery of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described below in conjunction with specific examples. It should be understood that the following examples are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0025] Figure 1 The system block diagram of the conversion circuit of the lithium battery to dry cell of the present invention is shown in FIG. Figure 1 As shown, the conversion circuit of the lithium battery to dry battery of the present invention is reusable, so the conversion circuit of the lithium battery to dry battery includes a charging module 10 and a discharging module 20 connected to the battery cell of the lithium battery. The input end of the charging module 10 is connected to an external power source to charge the battery cell of the lithium battery through the charging module 10, thereby realizing the repeated use of the lithium battery.

[0026] The output end of the discharge module 20 is connected to a load, and the output voltage of the discharge module 20 is The discharge curve of the discharge module 20 is the same as that of the dry cell. Therefore, the discharge module 20 can realize that the output voltage of the discharge module 20 changes linearly with the cell voltage and load current of the lithium battery, and realizes the same output voltage range as that of the dry cell.

[0027] like Figure 2 and Figure 3 The figure shows the discharge module of the conversion circuit of lithium battery to dry battery according to the first embodiment of the present invention. Figure 2 As shown, the discharge module 20 includes a reference voltage clamping module 21, a cell voltage sampling module 22, a load current sampling module 23, a current regulating module 24, an output voltage feedback module 25, and a power management module 26. The output ends of the reference voltage clamping module 21, the cell voltage sampling module 22, the load current sampling module 23, and the current regulating module 24 are all connected to the reference voltage. Connect the output terminal of the output voltage feedback module 25 to the feedback voltage The two input terminals of the power management module 26 are respectively connected to the reference voltage and feedback voltage , and its output end is connected to the output voltage output by the power management module 26, so that the feedback voltage With reference voltage equal, so that the output voltage of the discharge module 20 The output voltage is consistent with that of dry batteries, realizing the conversion of lithium batteries into dry batteries.

[0028] like Figure 3 As shown, the feedback voltage The output voltage of the discharge module 20 In this embodiment, the output voltage feedback module 25 includes a sixth resistor connected in series. and the seventh resistor As a second resistor voltage-dividing structure, the input end of the second resistor voltage-dividing structure is connected to the output voltage of the discharge module 20. Connection. The sixth resistor and the seventh resistor The connection point is used as the output terminal to provide feedback voltage , the seventh resistor The other end (i.e., the high voltage side of the output voltage feedback network) is used as the input end of the output voltage feedback module 25 to connect the output voltage , the sixth resistor The other end is grounded.

[0029] Therefore, the feedback voltage for: , in, is the output voltage, is the resistance value of the sixth resistor, is the resistance value of the seventh resistor.

[0030] The power management module 26 adopts a conventional buck step-down structure, which includes an error amplifier 261, a driving module 262, a set of parallel buck circuit switch tubes 263, and a filter circuit 264 connected in sequence. The buck circuit switch tube 263 includes a first PMOS tube and a first NMOS tube. The drains of the first PMOS tube and the first NMOS tube are both connected to the filter circuit 264. The source of the first PMOS tube is connected to the cell voltage of the lithium battery. The source of the first NMOS tube is grounded. The error amplifier 261, the driving module 262, and the buck circuit switch tube 263 are arranged inside the chip. The filter circuit 264 is arranged outside the chip, including an inductor connected to the buck circuit switch tube 263 at one end and a grounded capacitor connected to the other end of the inductor. The connection point between the inductor and the grounded capacitor is the output end of the power management module 26, which is used to connect the load to provide an output voltage to the load. and load current .

[0031] The cell voltage sampling module 22 includes an input terminal and a cell voltage A resistor voltage-dividing structure connected to the resistor voltage-dividing structure includes a first resistor connected in series and the second resistor The high voltage side of the resistor voltage divider structure and the cell voltage of the lithium battery The connection point between the first resistor and the second resistor is the output end of the resistor voltage divider structure and is connected to the reference voltage. Thus, the reference voltage The cell voltage is adjusted by the resistor voltage divider structure sampling.

[0032] Therefore, the reference voltage The output voltage of the discharge module 20 is generated by the resistor voltage division structure, without considering other modules. The initial reference voltage generated by resistor voltage division for: , in, is the cell voltage of the lithium battery, is the second resistor.

[0033] The load current sampling module 23 includes a current sampling amplifier 231 and a current sampling switch N2 connected to the output end of the current sampling amplifier. The positive phase voltage input end of the current sampling amplifier is connected to the sampling current and compensation resistor Connection, compensation resistor The other end of the ground is used to obtain the sampling current In the compensation resistor The voltage drop across the sampling current Through the load current The inverting voltage input terminal of the current sampling amplifier and the fourth resistor and the low voltage side of the current sampling switch tube N2, the fourth resistor The other end of the current sampling switch tube N2 is grounded, the gate of the current sampling switch tube N2 is connected to the input end of the current sampling amplifier 231, and the high voltage side of the current sampling switch tube N2 is connected to the reference voltage In this embodiment, the current sampling switch tube is an NMOS tube. Therefore, the inverting voltage input terminal of the current sampling amplifier is the internal resistance compensation current output by the load current sampling module. In the fourth resistor The pressure drop on.

[0034] Sampling current The load current is sensed by the load current sampling circuit. The load current sampling circuit can be obtained by sampling, and there are many circuit implementations, which will not be described here. In this embodiment, the sampling ratio of the load current sampling circuit is 1 / N, so the sampling current for: , Among them, 1 / N is the sampling ratio of the load current sampling circuit, is the load current.

[0035] Internal resistance compensation current output by the load current sampling module for: , in, is the sampling current, is the compensation resistor, is the fourth resistor, 1 / N is the sampling ratio of the load current sampling circuit, is the load current.

[0036] That is to say, the load current sampling module 23 is used to output an internal resistance compensation current proportional to the load current. .

[0037] Among them, the compensation resistor Can be external (i.e. set outside the chip) or internal; through external compensation resistor , which can easily realize different load current compensation coefficients. Compensation resistor , the fourth resistor The numerical value of the sampling ratio 1 / N is adjustable and the design is very flexible. The design adjustment is based on the numerical simulation obtained at the end. Sampling and compensation resistors To simulate the voltage change caused by the internal resistance of the battery cell and realize the internal resistance compensation of the battery cell.

[0038] The current regulation module 24 is used to provide a fixed regulation current. , the regulated current Used to adjust the output voltage range.

[0039] Regulating current It is an additional deviation introduced to adjust the reference voltage , to achieve the same output voltage range as dry cell batteries.

[0040] In this embodiment, the current is adjusted The voltage is generated by regulating the current flowing through the fifth resistor To generate and regulate current for: , in, It is to regulate the current to generate voltage. is the fifth resistor. It is a fixed voltage value. The design of adjusting the current to generate the voltage V0 and the fifth resistor is also very flexible. As long as the final formula can be fitted, there is no rigid requirement.

[0041] The reference voltage clamping module 21 is used to clamp the reference voltage within the range of the threshold voltage, thereby ensuring that the range of the output voltage is consistent with the battery voltage and that the output voltage is not too high or too low.

[0042] The reference voltage clamping module 21 has a variety of implementations, as long as the reference voltage is clamped within the range of the threshold voltage so that the corresponding output voltage is consistent with the dry cell. For example, in this embodiment, the reference voltage clamping module 21 adopts one of the basic circuit structures, including a clamping circuit amplifier, the non-inverting input terminal of the clamping circuit amplifier is connected to the threshold voltage, and the inverting input terminal and the output terminal are both connected to the reference voltage. connection to achieve overvoltage protection.

[0043] In this embodiment, the reference voltage should be clamped at and between.

[0044] In summary, the reference voltage Satisfies the following formula: , in, To regulate the current, is the cell voltage of the lithium battery, is the reference voltage, is the second resistor, is the first resistor, It is the internal resistance compensation current output by the load current sampling module.

[0045] Therefore, the reference voltage for: , The power management module 26 can achieve the feedback voltage and the reference voltage to be equal through loop regulation, so the feedback voltage satisfies .

[0046] Output voltage for: , Can be simplified to: , in , , , the values ​​of these three values ​​can be obtained by curve fitting.

[0047] It can be clearly seen from the output formula that the output voltage of the discharge module 20 It decreases linearly with the decrease of cell voltage and decreases linearly with the increase of load current, which completely fits the discharge characteristics of dry cell.

[0048] like Figure 4 and Figure 5 Shown is a system block diagram and circuit diagram of a discharge module of a lithium battery to dry cell conversion circuit according to a second embodiment of the present invention.

[0049] like Figure 4 As shown, the discharge module 20 includes a reference voltage clamp module 21', a cell voltage sampling module 22', a current regulating module 24', a load current sampling module 23', an output voltage feedback module 25', and a power management module 26'. The output ends of the reference voltage clamp module 21', the cell voltage sampling module 22', and the current regulating module 24' are all connected to the reference voltage. The output terminals of the load current sampling module 23' and the output voltage feedback module 25' are connected to the feedback voltage connect.

[0050] The two input terminals of the power management module 26' are respectively connected to the reference voltage and feedback voltage The output terminal of the power management module 26' is connected to the output voltage output by the power management module 26', so that the feedback voltage With reference voltage equal, so that the output voltage of the discharge module 20 The output voltage is consistent with that of dry batteries, realizing the conversion of lithium batteries into dry batteries.

[0051] like Figure 5 As shown, the specific structures of the reference voltage clamping module 21', the battery cell voltage sampling module 22', the current regulation module 24', and the output voltage feedback module 25' and the connection method of their input and output ends are the same as the reference voltage clamping module 21, the battery cell voltage sampling module 22, the current regulation module 24, and the output voltage feedback module 25 in the first embodiment of the present invention.

[0052] Therefore, the reference voltage of the step-down circuit It consists of two parts. The first is to realize the voltage of the battery cell through the resistor voltage divider structure. Sampling; the second part is to regulate the current , used to adjust the reference voltage to ensure that the output voltage range is consistent with the dry cell output voltage.

[0053] like Figure 5 As shown, the discharge module of the lithium battery to dry battery conversion circuit according to the second embodiment of the present invention is different from the first embodiment only in that the output end of the load current sampling module 23' is connected to the feedback voltage and the load current sampling module 23 'comprises a current sampling amplifier and a current sampling switch connected to the output of the current sampling amplifier, the reverse voltage input terminal of the current sampling amplifier is simultaneously connected to the sampling current and compensation resistor Connection, compensation resistor The other end of the lithium battery cell voltage Connect so that the reverse voltage input terminal can obtain the cell voltage of the lithium battery Subtract the sample current In the compensation resistor The voltage drop across the sampling current Through the load current The positive phase voltage input terminal of the current sampling amplifier and the fourth resistor and the high voltage side of the current sampling switch tube, the fourth resistor The other end is connected to the lithium battery cell voltage The gate of the current sampling switch is connected to the input end of the current sampling amplifier, and the low voltage side of the current sampling switch is connected to the feedback voltage In this embodiment, the current sampling switch tube is a PMOS tube. Therefore, the inverting voltage input terminal of the current sampling amplifier is the internal resistance compensation current output by the load current sampling module. In the fourth resistor The pressure drop on.

[0054] Feedback voltage It consists of two parts, one is the output voltage The other part is obtained by resistor voltage division, and the other part is obtained by sampling the load current by the load current sampling module 23 ′.

[0055] Reference voltage The output voltage of the discharge module 20 is generated by the resistor voltage division, without considering other modules. The initial reference voltage generated by resistor voltage division for: .

[0056] In this embodiment, the current is adjusted The voltage is generated by regulating the current flowing through the fifth resistor To generate and regulate current for: , in, It is to regulate the current to generate voltage. is the fifth resistor. It is a fixed voltage value. The design of adjusting the current to generate the voltage V0 and the fifth resistor is also very flexible. As long as the final formula can be fitted, there is no rigid requirement.

[0057] In summary, the reference voltage Satisfies the following formula: , in, To regulate the current, is the cell voltage of the lithium battery, is the reference voltage, is the second resistor, is the first resistor.

[0058] Therefore, the reference voltage for: , When only considering the resistor voltage divider, the initial feedback voltage generated by the resistor voltage divider is for: , in, is the output voltage, is the resistance value of the sixth resistor, is the resistance value of the seventh resistor.

[0059] The load current sampling module can Sampling, the sampling ratio is 1 / N, then the sampling current for: , Among them, 1 / N is the sampling ratio of the load current sampling circuit, is the load current.

[0060] Internal resistance compensation current output by the load current sampling module for: , in, is the sampling current, is the compensation resistor, is the fourth resistor, 1 / N is the sampling ratio of the load current sampling circuit, is the load current. Among them, the compensation resistor Can be external or internal; through external compensation resistor , which can easily realize different load current compensation coefficients.

[0061] In summary, the feedback voltage Satisfies the following formula: , The feedback voltage for: .

[0062] The power management module 26 can achieve the feedback voltage and the reference voltage to be equal through loop regulation, so the feedback voltage satisfies .

[0063] Output voltage for: , Can be simplified to: , in, , , , the values ​​of these three values ​​can be obtained by curve fitting.

[0064] It can be clearly seen from the output formula that the output voltage of the discharge module 20 It decreases linearly with the decrease of cell voltage and decreases linearly with the increase of load current, which completely fits the discharge characteristics of dry cell.

[0065] like Figure 6 and Figure 7 Shown is a system block diagram and circuit diagram of a discharge module of a lithium battery to dry cell conversion circuit according to a third embodiment of the present invention.

[0066] like Figure 6 As shown, the discharge module 20 includes a reference voltage clamping module 21", a cell voltage sampling module 22", a load current sampling module 23", a current regulation module 24", an output voltage feedback module 25", and a power management module 26". Among them, the output ends of the reference voltage clamping module 21", the cell voltage sampling module 22", and the reference voltage Connection; the output end of the load current sampling module 23", the current regulation module 24" and the output voltage feedback module 25" are connected to the feedback voltage connect.

[0067] The two input terminals of the power management module 26" are respectively connected to the reference voltage and feedback voltage The output terminal of the power management module 26 is connected to the output voltage output by the power management module 26, so that the feedback voltage With reference voltage equal, so that the output voltage of the discharge module 20 The output voltage is consistent with that of dry batteries, realizing the conversion of lithium batteries into dry batteries.

[0068] Therefore, the reference voltage The cell voltage is adjusted by the resistor voltage divider structure Sampling. Feedback voltage It consists of three parts: output voltage After resistor voltage division, load current sampling and Figure 5 are the same, the only difference is that the current regulation module 24" and the feedback voltage connection so that the feedback voltage Additional regulated current , used to adjust the reference voltage to ensure that the output voltage range is consistent with the dry cell output voltage.

[0069] The reference voltage is generated by resistor voltage division. for: .

[0070] When only considering the resistor voltage divider, the initial feedback voltage generated by the resistor voltage divider is for: , in, is the output voltage, is the resistance value of the sixth resistor, is the resistance value of the seventh resistor.

[0071] The load current sampling module can Sampling, the sampling ratio is 1 / N, then the sampling current for: , Among them, 1 / N is the sampling ratio of the load current sampling circuit, is the load current.

[0072] Internal resistance compensation current output by the load current sampling module for: , in, is the sampling current, is the compensation resistor, is the fourth resistor, 1 / N is the sampling ratio of the load current sampling circuit, is the load current. Among them, the compensation resistor Can be external or internal; through external compensation resistor , which can easily realize different load current compensation coefficients.

[0073] In this embodiment, the current is adjusted The voltage is generated by regulating the current flowing through the fifth resistor To generate and regulate current for: , in, It is to regulate the current to generate voltage. is the fifth resistor. It is a fixed voltage value. The design of adjusting the current to generate the voltage V0 and the fifth resistor is also very flexible. As long as the final formula can be fitted, there is no rigid requirement.

[0074] In summary, the feedback voltage Satisfies the following formula: , The feedback voltage for: , The power management module 26 can achieve the feedback voltage and the reference voltage to be equal through loop regulation, so the feedback voltage satisfies .

[0075] Output voltage for: , Can be simplified to: , in, , , , the values ​​of these three values ​​can be obtained by curve fitting.

[0076] It can be clearly seen from the output formula that the output voltage of the discharge module 20 It decreases linearly with the decrease of cell voltage and decreases linearly with the increase of load current, which completely fits the discharge characteristics of dry cell.

[0077] Since all the above structures will output very low voltage when the voltage is low and the load current is large, they cannot be used as batteries; or when the cell voltage is high and the load current is small, they will output a higher voltage, causing damage to the subsequent electronic components. The output voltage range of the dry cell is 0.6V-1.58V. The reference voltage clamping module described above can solve this problem. The reference voltage clamping module is used to clamp the reference voltage within the threshold voltage range, thereby ensuring that the output voltage range is consistent with the dry cell voltage and that the output voltage is not too high or too low. The reference voltage clamping module has a variety of implementation methods, as long as the reference voltage is clamped within the threshold voltage range so that the corresponding output voltage is consistent with the dry cell voltage.

[0078] exist Figure 3 The reference voltage should be clamped at and between Figure 5 The reference voltage should be clamped at and between Figure 7 The reference voltage should be clamped at and between.

[0079] Fig. 8A and Figure 8B This is a curve fitting specifically implemented according to the present invention, where the abscissa is the battery discharge time and the ordinate is the dry cell voltage or the output voltage of the lithium-to-dry structure designed in this patent. Fig. 8A and Figure 8BIt can be seen that the present invention can completely fit the discharge curve of both AA and AAA batteries. like Fig. 8A and Figure 8B As shown, the discharge characteristics of the No. 5 battery under the conditions of 240mA, 480mA, and 1.2A, and the discharge characteristics of the No. 7 battery under the conditions of 75mA, 150mA, 350mA, and 750mA are shown. The conversion circuit of the lithium battery to the dry battery of the present invention can realize the output of the lithium battery cell as the voltage characteristic of the dry battery. The conversion circuit of the lithium battery to the dry battery of the present invention sets a cell voltage sampling module in the discharge module to realize that the output voltage decreases as the battery voltage decreases, and sets a load current sampling module to provide an internal resistance supplementary current to realize that the output voltage decreases as the load current increases, so that the discharge curve of the output voltage can completely fit the voltage characteristics of the dry battery.

[0080] The above is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. The above embodiments of the present invention can also be modified in various ways. All simple, equivalent changes and modifications made according to the claims and the description of the present invention fall within the scope of protection of the claims of the present invention. The contents not described in detail in the present invention are all conventional technical contents.

Claims

1. A lithium battery to dry cell conversion circuit, characterized in that: It includes a discharge module connected to a cell of a lithium battery, the discharge module includes a cell voltage sampling module, a load current sampling module, an output voltage feedback module, and a power management module; two input ends of the power management module are respectively connected to a reference voltage and a feedback voltage, the output end of the cell voltage sampling module is connected to the reference voltage, the output end of the output voltage feedback module is connected to the feedback voltage, the output end of the load current sampling module is connected to one of the reference voltage and the feedback voltage, and the load current sampling module is used to output an internal resistance compensation current that is proportional to the load current.

2. The lithium battery to dry cell conversion circuit according to claim 1, characterized in that: The cell voltage sampling module includes a resistor voltage-dividing structure whose input end is connected to the cell voltage; and / or the output voltage feedback module includes a second resistor voltage-dividing structure whose input end is connected to the output voltage of the discharge module.

3. The lithium battery to dry cell conversion circuit according to claim 1, characterized in that: The load current sampling module includes a current sampling amplifier and a current sampling switch tube connected to the output end of the current sampling amplifier.

4. The lithium battery to dry cell conversion circuit according to claim 3, characterized in that: The output end of the load current sampling module is connected to the reference voltage; the positive phase voltage input end of the current sampling amplifier is connected to the sampling current and the compensation resistor at the same time, and the other end of the compensation resistor is grounded to obtain the voltage drop of the sampling current on the compensation resistor, and the sampling current is obtained by sampling the load current; The inverting voltage input terminal of the current sampling amplifier is connected to one end of the fourth resistor and the low voltage side of the current sampling switch tube, the other end of the fourth resistor is grounded, the gate of the current sampling switch tube is connected to the input terminal of the current sampling amplifier, and the high voltage side of the current sampling switch tube is connected to the reference voltage.

5. The lithium battery to dry cell conversion circuit according to claim 3, characterized in that: The output end of the load current sampling module is connected to the feedback voltage; the reverse voltage input end of the current sampling amplifier is connected to the sampling current and the compensation resistor at the same time, and the other end of the compensation resistor is connected to the cell voltage of the lithium battery, so that the reverse voltage input end obtains the cell voltage of the lithium battery minus the voltage drop of the sampling current on the compensation resistor, and the sampling current is obtained by sampling the load current; the positive phase voltage input end of the current sampling amplifier is connected to one end of the fourth resistor and the high voltage side of the current sampling switch tube, the other end of the fourth resistor is connected to the cell voltage of the lithium battery, the gate of the current sampling switch tube is connected to the input end of the current sampling amplifier, and the low voltage side of the current sampling switch tube is connected to the feedback voltage.

6. The lithium battery to dry cell conversion circuit according to claim 4 or 5, characterized in that: The compensation resistor is external or internal.

7. The lithium battery to dry cell conversion circuit according to claim 1, characterized in that: The power management module adopts a traditional buck step-down structure, which includes an error amplifier, a driving module, a group of parallel buck circuit switch tubes, and a filter circuit connected in sequence.

8. The lithium battery to dry cell conversion circuit according to claim 1, characterized in that: One of the reference voltage and the feedback voltage is connected to a current regulating module, and the current regulating module is used to provide a fixed regulating current.

9. The lithium battery to dry cell conversion circuit according to claim 1, characterized in that: The reference voltage is connected to a reference voltage clamping module, and the reference voltage clamping module is used to clamp the reference voltage within a threshold voltage range.

10. The lithium battery to dry cell conversion circuit according to claim 1, characterized in that: It also includes a charging module connected to the battery cell of the lithium battery, and the charging module is used to charge the battery cell of the lithium battery.

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