Novel current sampling circuit
By designing a new current sampling circuit including fuse, comparison circuit and filter module, the problems of low accuracy and high cost in the prior art are solved, high-precision current sampling is achieved and production costs are reduced.
Patent Information
- Application Number
- CN202421938254.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-09
- Publication Date
- 2025-06-27
- Estimated Expiration
- 2034-08-09
AI Technical Summary
The existing current sampling technology has problems of low accuracy and high cost, especially when used in chargers to detect battery charging current, traditional Hall sensors or current transformers are difficult to apply in large quantities, and the results of test resistances are prone to deviations.
A new type of current sampling circuit is designed, including a fuse, a comparison circuit, a first measurement circuit, a second measurement circuit and an interference prevention module. The voltage drop generated by the internal resistance of the fuse is combined with the comparison circuit and a filter module to collect and calculate the current value, improve the sampling accuracy, and reduce the dependence on expensive sensors.
High-precision measurement of current sampling is achieved, reducing production costs, no need for expensive Hall sensors or current sensors, and avoiding results deviations caused by test resistance.
Smart Images
Figure CN223038037U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the field of charging parts, and specifically, to a novel current sampling circuit. Background Art
[0002] Current sampling refers to a method of detecting and analyzing the current in a circuit, which is applied to the testing and detection of various power equipment. Since the current value in a circuit element cannot be directly measured, the principle of current sampling is usually to use a resistor with a relatively small resistance value connected in series inside the circuit, detect the voltage across its two ends, and calculate the magnitude of the current passing through the resistor based on its own resistance value, so as to achieve the purpose of detecting the circuit current. Generally, during the process of charging a battery with a charger, if the charging power of the battery is about to be full, the charger will reduce the output current value to prevent overcharging of the battery. At this time, current sampling is required to determine the magnitude of the current value in order to adjust the reduced current value. And the components for current sampling need to use Hall sensors or current transformers. Although the accuracy of these components is high, their usage cost is also high and they cannot be used in large quantities; while using the method of test resistors, due to the different resistance values between each resistor, the test results will deviate. Summary of the Utility Model
[0003] Aiming at the deficiencies of the prior art, the utility model provides a novel current sampling circuit.
[0004] The purpose of the utility model is achieved through the following solutions:
[0005] A novel current sampling circuit includes a fuse FUSE, a comparison circuit, a first measurement circuit, a second measurement circuit, and an anti-interference module. The fuse FUSE is electrically connected to the comparison circuit, the first measurement circuit, and the second measurement circuit respectively. The comparison circuit is electrically connected to the first measurement circuit, the second measurement circuit, and the anti-interference module respectively. The first measurement circuit is electrically connected to the second measurement circuit. The second measurement circuit is electrically connected to the anti-interference module. Among them, the measurement ranges of the first measurement circuit and the second measurement circuit are different.
[0006] In one implementation, the comparison circuit includes a first comparison module, a first filtering module, and a second filtering module. The first comparison module is electrically connected to the first filtering module and the second filtering module respectively. The first comparison module is electrically connected to the fuse FUSE, the first measurement circuit, the second measurement circuit, and the anti-interference module respectively.
[0007] In one embodiment, the first comparison module includes an operational amplifier OP1, a reference power supply VCC, and an input power supply VIN. The operational amplifier OP1 has a terminal 1, a terminal 2, a terminal 3, a terminal 4, and a terminal 5. The terminal 1 of the operational amplifier OP1 is electrically connected to the anti-interference module. A first filtering module is connected in parallel to the terminal 1 and the terminal 5 of the operational amplifier OP1, and the terminal 5 is also electrically connected to the signal ground SGND. The terminal 2 of the operational amplifier OP1 is electrically connected to the reference power supply VCC. The terminal 3 of the operational amplifier OP1 is electrically connected to a fuse FUSE, a first measurement circuit, and a second comparison circuit respectively. The terminal 4 of the operational amplifier OP1 is electrically connected to the input power supply VIN and a second filtering module (23) respectively.
[0008] In one embodiment, the first filtering module includes a capacitor C1, and the second filtering module includes a capacitor C2. The capacitor C1 and C2 each have a terminal 1 and a terminal 2. The terminal 1 and the terminal 2 of the capacitor C1 are electrically connected to the first comparison module. The terminal 1 of the capacitor C2 is electrically connected to the first comparison module (21), and the terminal 2 of the capacitor C2 is electrically connected to the signal ground SGND.
[0009] In one embodiment, the first measurement circuit includes a first protection module, a third filtering module, a first measurement module, a first feedback module, and a first output module. The first protection module is electrically connected to the fuse FUSE, a comparison circuit, a second measurement circuit, a third filtering module, a second comparison module, and a first feedback module respectively. The third filtering module is electrically connected to the second comparison module. The second comparison module is electrically connected to the first feedback module and a first output circuit respectively. The first feedback module is electrically connected to the output circuit.
[0010] In one embodiment, the first protection module includes a resistor R1 and a resistor R2. The resistor R1 and R2 each have a terminal 1 and a terminal 2.
[0011] The third filtering module includes a capacitor C3 and a resistor R4. The capacitor C3 and R4 each have a terminal 1 and a terminal 2, and the terminal 1 and the terminal 2 of the capacitor C3 and the resistor R4 are connected in parallel.
[0012] The second comparison module includes an operational amplifier OP2. The operational amplifier OP2 has a terminal 1, a terminal 2, and a terminal 3.
[0013] The first feedback module includes a resistor R3 and a capacitor C4. The resistor R3 and C4 each have a terminal 1 and a terminal 2, and the terminal 1 and the terminal 2 of the resistor R3 and the capacitor C4 are connected in parallel.
[0014] The first output module includes a resistor R5 and a diode D3. The resistor R5 and D3 each have a terminal 1 and a terminal 2.
[0015] The first terminal of resistor R1 is electrically connected to fuse FUSE and the second measurement circuit respectively, and its second terminal is electrically connected to the first terminal of resistor R3, capacitor C4 and the second terminal of operational amplifier OP2; the first terminal of resistor R2 is electrically connected to fuse FUSE, the comparison circuit and the second measurement circuit respectively, and the second terminal of resistor R2 is electrically connected to the first terminal of capacitor C3, resistor R4 and the third terminal of operational amplifier OP2; the first terminals of capacitor C3 and resistor R4 are electrically connected to the third terminal of operational amplifier OP2, and the second terminals of capacitor C3 and resistor R4 are electrically connected to signal ground SGND; the first terminals of resistor R3 and capacitor C4 are electrically connected to the second terminal of operational amplifier OP2, and the second terminals of resistor R3 and capacitor C4 are electrically connected to the first terminal of operational amplifier OP2; the first terminal of resistor R5 is electrically connected to the first terminal of operational amplifier OP2, the second terminal of resistor R5 is electrically connected to the first terminal of diode D3, and the second terminal of diode D3 is electrically connected to the output terminal.
[0016] In one implementation, the second measurement circuit includes a second protection module, a fourth filtering module, a second measurement module, a second feedback module and a second output module. The second protection module is electrically connected to fuse FUSE, the comparison circuit, the first measurement circuit, the fourth filtering module, the third comparison module and the second feedback module respectively. The fourth filtering module is electrically connected to the third comparison module. The third comparison module is electrically connected to the second feedback module and the second output module respectively. The second feedback module is electrically connected to the output circuit.
[0017] In one implementation, the second protection module includes resistor R6 and resistor R7. Resistor R6 and resistor R7 each have a first terminal and a second terminal.
[0018] The fourth filtering module includes capacitor C5 and resistor R9. Capacitor C5 and resistor R9 each have a first terminal and a second terminal, and the first terminals and the second terminals of capacitor C5 and resistor R9 are connected in parallel.
[0019] The second comparison module includes operational amplifier OP3. Operational amplifier OP3 has a first terminal, a second terminal and a third terminal.
[0020] The second feedback module includes resistor R8 and capacitor C6. Resistor R8 and capacitor C6 each have a first terminal and a second terminal, and the first terminals and the second terminals of resistor R8 and capacitor C6 are connected in parallel.
[0021] The second output module includes resistor R10 and diode D2. Resistor R10 and diode D2 each have a first terminal and a second terminal.
[0022] The first terminal of resistor R6 is electrically connected to fuse FUSE and the first measurement circuit respectively, and its second terminal is electrically connected to the first terminal of resistor R8, capacitor C6 and the second terminal of operational amplifier OP3; the first terminal of resistor R7 is electrically connected to fuse FUSE, the comparison circuit and the first measurement circuit respectively, and the second terminal of resistor R7 is electrically connected to the first terminal of capacitor C5, resistor R9 and the third terminal of operational amplifier OP3; the first terminals of capacitor C5 and resistor R9 are electrically connected to the third terminal of operational amplifier OP3, and the second terminals of capacitor C5 and resistor R9 are electrically connected to signal ground SGND; the first terminals of resistor R8 and capacitor C6 are electrically connected to the second terminal of operational amplifier OP3, and the second terminals of resistor R8 and capacitor C6 are electrically connected to the first terminal of operational amplifier OP3; the first terminal of resistor R10 is electrically connected to the first terminal of operational amplifier OP3, the second terminal of resistor R10 is electrically connected to the first terminal of diode D2, and the second terminal of diode D2 is electrically connected to the output terminal.
[0023] In one of the embodiments, the anti-interference module includes diode D1. Diode D1 has a first terminal and a second terminal. The first terminal of diode D1 is electrically connected to the second measurement circuit, and the first terminal of diode D1 is electrically connected to the comparison circuit.
[0024] Compared with the prior art, the present utility model has at least the following advantages:
[0025] A novel current sampling circuit of the present utility model calculates the current by collecting the voltage value of the fuse and the internal resistance of the fuse through sampling the voltage, by means of the voltage drop generated by the internal resistance of the fuse when the current flows through, through the fuse arranged inside the charger and different resistance value resistors arranged in the first measurement circuit and the second measurement circuit. The comparison circuit determines whether to use the first measurement circuit or the second measurement circuit by judging the magnitude of the measured voltage, thereby improving the accuracy of the sampled current and eliminating the need to use relatively expensive sensor components such as Hall sensors and current sensors, thus reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] The drawings described herein are used to provide a further understanding of the present application and form a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation to the present application. In the drawings:
[0027] Figure 1 is the circuit structure diagram of the present utility model;
[0028] Among them, the reference numerals are as follows: 1. FUSE; 2. comparison circuit; 21. first comparison module; 22. first filtering module; 23. second filtering module; 3. first measurement circuit; 31. first protection module; 32. second filtering module; 33. first measurement module; 34. first feedback module; 35. first output module; 4. second measurement circuit; 41. second protection module; 42. third filtering module; 43. second measurement module; 44. second feedback module; 45. second output module; 5. anti-interference module. Detailed implementation manners
[0029] Multiple implementation manners of the present utility model will be disclosed below with reference to the drawings. For the sake of clarity, many practical details will be described together in the following description. However, it should be understood that these practical details are not used to limit the present utility model. That is to say, in some implementation manners of the present utility model, these practical details are not necessary. In addition, for the purpose of simplifying the drawings, some well-known and commonly used structures and components will be shown in the drawings in a simple schematic manner.
[0030] It should be noted that all directional indications such as up, down, left, right, front, back... in the embodiments of the present utility model are only used to explain the relative positional relationship and movement conditions between components in a specific posture as shown in the drawings. If this specific posture changes, then the directional indications will also change accordingly.
[0031] In addition, in the present utility model, descriptions such as "first" and "second" are only for descriptive purposes, and do not particularly refer to the order or sequence, nor are they used to limit the present utility model. They are only used to distinguish components or operations described with the same technical terms, and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on the fact that those skilled in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.
[0032] In order to further understand the content, features and effects of the present utility model, the following embodiments are cited and described in detail with reference to the drawings as follows:
[0033] As Figure 1As shown in the figure, a new type of current sampling circuit includes a fuse FUSE1, a comparison circuit 2, a first measurement circuit 3, a second measurement circuit 4, and an anti-interference module 5. The fuse FUSE1 is electrically connected to the comparison circuit 2, the first measurement circuit 3, and the second measurement circuit 4 respectively. The comparison circuit 2 is electrically connected to the first measurement circuit 3, the second measurement circuit 4, and the anti-interference module 5 respectively. The first measurement circuit 3 is electrically connected to the second measurement circuit 4. The second measurement circuit 4 is electrically connected to the anti-interference module 5. Among them, the measurement ranges of the first measurement circuit 3 and the second measurement circuit 4 are different.
[0034] It should be noted that the fuse FUSE 1 is the voltage sampling object. The voltage value of the fuse FUSE 1 is detected and calculated with the internal resistance value of the fuse FUSE 1 to obtain the voltage value of the fuse FUSE 1. The first measurement circuit 3 and the second measurement circuit 4 are used to measure the voltage value on the fuse FUSE 1. The comparison circuit 2 is used to compare the voltage on the fuse FUSE 1 with its own reference voltage, and then switch the first measurement circuit 3 or the second measurement circuit 4 to measure.
[0035] Further, the comparison circuit 2 includes a first comparison module 21, a first filtering module 22, and a second filtering module 23. The first comparison module 21 is electrically connected to the first filtering module 22 and the second filtering module 23 respectively. The first comparison module 21 is electrically connected to the fuse FUSE 1, the first measurement circuit 3, the second measurement circuit 4, and the anti-interference module 5 respectively. Among them, the first comparison module 21 is used to compare and judge the magnitude of the voltage on the fuse FUSE 1 and the reference voltage value input by itself. The first filtering module 22 is used to improve the stability of the amplifier, suppress high-frequency oscillation, improve the output driving ability, and reduce zero drift. The second filtering module is used to filter the input power supply VIN to reduce voltage ripple.
[0036] Specifically, the first comparison module 21 includes an operational amplifier OP1, a reference power supply VCC, and an input power supply VIN. The operational amplifier OP1 has a terminal 1, a terminal 2, a terminal 3, a terminal 4, and a terminal 5. The terminal 1 of the operational amplifier OP1 is electrically connected to the anti-interference module 5. The terminal 1 and the terminal 5 of the operational amplifier OP1 are connected in parallel with the first filtering module 22, and the terminal 5 is also electrically connected to the signal ground SGND. The terminal 2 of the operational amplifier OP1 is electrically connected to the reference power supply VCC. The terminal 3 of the operational amplifier OP1 is electrically connected to the fuse FUSE1, the first measurement circuit 3, and the second comparison circuit 4 respectively. The terminal 4 of the operational amplifier OP1 is electrically connected to the input power supply VIN and the second filtering module respectively.
[0037] Specifically, the first filtering module 22 includes a capacitor C1, and the second filtering module 23 includes a capacitor C2. The capacitor C1 and C2 each have a terminal 1 and a terminal 2. The terminal 1 and terminal 2 of the capacitor C1 are electrically connected to the first comparison module 21; the terminal 1 of the capacitor C2 is electrically connected to the first comparison module 21, and the terminal 2 of the capacitor C2 is electrically connected to the signal ground SGND.
[0038] Among them, the terminal 1 and terminal 5 of the operational amplifier OP1 are connected in parallel with the terminal 1 and terminal 2 of the capacitor C1, and the terminal 5 of the operational amplifier OP1 is also electrically connected to the signal ground SGND; the terminal 1 of the capacitor C2 is electrically connected to the terminal 4 of the operational amplifier and the input power supply VIN, and the terminal 2 of the capacitor C2 is electrically connected to the signal ground SGND. It should be noted that the capacitor C1 connected in parallel between the terminal 1 and terminal 5 of the operational amplifier OP1 can improve the output driving ability and filter the output level signal; the capacitor C2 is used to filter the input voltage VIN to reduce the voltage ripple.
[0039] Further, the first measurement circuit 3 includes a first protection module 31, a third filtering module 32, a first measurement module 33, a first feedback module 34 and a first output module 35. The first protection module 31 is electrically connected to the fuse FUSE1, the comparison circuit 2, the second measurement circuit 3, the third filtering module 32, the second comparison module 33 and the first feedback module 34 respectively; the third filtering module 32 is electrically connected to the second comparison module 33, and the second comparison module 33 is electrically connected to the first feedback module 34 and the first output circuit 35 respectively. The first feedback module 34 is electrically connected to the output circuit 35. Among them, the first protection module 31 is used to protect the first measurement module 33 to prevent the voltage input to the first measurement module by the fuse FUSE 1 from being too large; the third filtering module 32 is used to limit the voltage range input to the first measurement module 33 by the fuse FUSE 1 to control the low-level and high-level responses of the first measurement module 33, thereby realizing the filtering of the input voltage; the first measurement module 33 is used to measure the voltage input by the fuse FUSE 1; the first feedback module 34 is used to adjust the gain and output of the first measurement module to make the first measurement circuit 3 operate more stably; the first output module 35 is used to output the measurement result.
[0040] Specifically, the first protection module 31 includes a resistor R1 and a resistor R2. The resistor R1 and the resistor R2 each have a terminal 1 and a terminal 2. The third filtering module 32 includes a capacitor C3 and a resistor R4. The capacitor C3 and the resistor R4 each have a terminal 1 and a terminal 2, and the terminal 1 and the terminal 2 of the capacitor C3 and the resistor R4 are connected in parallel. The second comparison module 33 includes an operational amplifier OP2. The operational amplifier OP2 has a terminal 1, a terminal 2, and a terminal 3. The first feedback module 34 includes a resistor R3 and a capacitor C4. The resistor R3 and the capacitor C4 each have a terminal 1 and a terminal 2, and the terminal 1 and the terminal 2 of the resistor R3 and the capacitor C4 are connected in parallel. The first output module 35 includes a resistor R5 and a diode D3. The resistor R5 and the diode D3 each have a terminal 1 and a terminal 2.
[0041] Among them, the terminal 1 of the resistor R1 is electrically connected to the fuse FUSE 1 and the second measurement circuit 3 respectively, and its terminal 2 is electrically connected to the terminal 1 of the resistor R3 and the capacitor C4 and the terminal 2 of the operational amplifier OP2. The terminal 1 of the resistor R2 is electrically connected to the fuse FUSE, the terminal 3 of the operational amplifier OP1, and the second measurement circuit 3 respectively. The terminal 2 of the resistor R2 is electrically connected to the terminal 1 of the capacitor C3 and the resistor R4 and the terminal 3 of the operational amplifier OP2 respectively. The terminal 1 of the capacitor C3 and the resistor R4 is electrically connected to the terminal 3 of the operational amplifier OP2, and the terminal 2 of the capacitor C3 and the resistor R4 is electrically connected to the signal ground SGND. The terminal 1 of the resistor R3 and the capacitor C4 is electrically connected to the terminal 2 of the operational amplifier OP2, and the terminal 2 of the resistor R3 and the capacitor C4 is electrically connected to the terminal 1 of the operational amplifier OP2. The terminal 1 of the resistor R5 is electrically connected to the terminal 1 of the operational amplifier OP2, the terminal 2 of the resistor R5 is electrically connected to the terminal 1 of the diode D3, and the terminal 2 of the diode D3 is electrically connected to the output terminal. It should be noted that the resistor R1 and the resistor R2 are used to protect the operational amplifier OP2 to prevent the voltage input to the operational amplifier OP2 by the fuse FUSE 1 from being too large. The terminal 1 and the terminal 2 of the capacitor C3 and the resistor R4 are connected in parallel to form a band-pass filter, which is used to limit the voltage range input to the operational amplifier circuit OP2 by the fuse FUSE 1 to control the low-level and high-level responses of the operational amplifier OP2, so as to realize the filtering of the input voltage. After the resistor R3 and the capacitor C4 are connected in parallel and then connected in parallel with the terminal 2 and the terminal 1 of the operational amplifier OP2 to form a feedback loop, and then compared with the original input voltage of the operational amplifier OP2, it is used to adjust the gain and output of the operational amplifier OP2, so that the first measurement circuit 3 operates more stably. The resistor R5 outputs voltage to prevent the output voltage from being too large. The diode D3 is used to input a high-level signal.
[0042] Furthermore, the second measurement circuit 4 includes a second protection module 41, a fourth filtering module 42, a third comparison module 43, and a second feedback module 44. The second protection module 41 is electrically connected to the fuse FUSE 1, the comparison circuit 2, the first measurement circuit 3, the fourth filtering module 42, the third comparison module 43, and the second feedback module 44 respectively. The fourth filtering module 42 is electrically connected to the third comparison module 43. The third comparison module 43 is electrically connected to the second feedback module 44 and the second output module 45 respectively. The second feedback module 44 is electrically connected to the output circuit 45. Among them, the functions of the second protection module 41, the fourth filtering module 42, the second measurement module 43, the second feedback module 44, and the second output module 45 are the same as those of the first protection module 31, the third filtering module 32, the first measurement module 33, the first feedback module 34, and the first output module 35, and will not be elaborated here.
[0043] Specifically, the second protection module 41 includes a resistor R6 and a resistor R7. The resistor R6 and the resistor R7 each have a terminal 1 and a terminal 2. The fourth filtering module 42 includes a capacitor C5 and a resistor R9. The capacitor C5 and the resistor R9 each have a terminal 1 and a terminal 2, and the terminal 1 and the terminal 2 of the capacitor C5 and the resistor R9 are connected in parallel. The third comparison module 43 includes an operational amplifier OP3. The operational amplifier OP3 has a terminal 1, a terminal 2, and a terminal 3. The second feedback module 44 includes a resistor R8 and a capacitor C6. The resistor R8 and the capacitor C6 each have a terminal 1 and a terminal 2, and the terminal 1 and the terminal 2 of the resistor R8 and the capacitor C6 are connected in parallel. The second output module 45 includes a resistor R10 and a diode D2. The resistor R10 and the diode D2 each have a terminal 1 and a terminal 2.
[0044] Among them, the terminal 1 of the resistor R6 is electrically connected to the fuse FUSE and the terminal 1 of the resistor R1 respectively, and its terminal 2 is electrically connected to the terminal 1 of the resistor R8 and the capacitor C6 and the terminal 2 of the operational amplifier OP3. The terminal 1 of the resistor R7 is electrically connected to the fuse FUSE, the terminal 3 of the operational amplifier OP1, and the terminal 1 of the resistor R2 respectively. The terminal 2 of the resistor R7 is electrically connected to the terminal 1 of the capacitor C5 and the resistor R9 and the terminal 3 of the operational amplifier OP3. The terminal 1 of the capacitor C5 and the resistor R9 is electrically connected to the terminal 3 of the operational amplifier OP3, and the terminal 2 of the capacitor C5 and the resistor R9 is electrically connected to the signal ground SGND. The terminal 1 of the resistor R8 and the capacitor C6 is electrically connected to the terminal 2 of the operational amplifier OP3, and the terminal 2 of the resistor R8 and the capacitor C6 is electrically connected to the terminal 1 of the operational amplifier OP3. The terminal 1 of the resistor R10 is electrically connected to the terminal 1 of the operational amplifier OP3, the terminal 2 of the resistor R10 is electrically connected to the terminal 1 of the diode D2, and the terminal 2 of the diode D2 is electrically connected to the output terminal.
[0045] Further, the anti-interference module 5 includes a diode D1. The diode D1 has a terminal 1 and a terminal 2. The terminal 1 of the diode D1 is electrically connected to the second measurement circuit 4, and the terminal 1 of the diode D1 is electrically connected to the comparison circuit 2.
[0046] It should be noted that the resistance values of the resistors R1 and R2 are smaller than those of the resistors R6 and R7; the resistance value of the resistor R3 is smaller than that of the resistor R8; the resistance value of the resistor R4 is smaller than that of the resistor R9. Thus, the second measurement circuit 4 can withstand a higher voltage input, so that the measurement range of the second measurement circuit 4 is larger than that of the first measurement circuit 3.
[0047] In summary, in specific implementation, the current of the DC power supply flows into the fuse FUSE 1. At this time, a voltage drop is generated on the fuse FUSE 1, and thus the voltage on the fuse FUSE 1 is input to the operational amplifier OP1 of the comparison circuit 2. The voltage of the fuse FUSE 1 is input from the terminal 3 of the operational amplifier OP1. At the same time, the reference voltage VCC is input to the terminal 2 of the operational amplifier OP1. Using the characteristic that the operational amplifier OP1 is used as a voltage comparator, when the voltage at the input terminal 2 is greater than the voltage at the input terminal 3, the voltage signal at the output terminal 2 is output; otherwise, the voltage signal at the output terminal 3 is output. In this embodiment, the output of the terminal 2 of the operational amplifier OP1 is a low-level signal, and the output of the terminal 3 is a high-level signal. When the voltage of the fuse FUSE 1 at the input terminal 3 is greater than the reference voltage VCC at the input terminal 2, a high-level signal is output; otherwise, a low-level signal is output.
[0048] In this embodiment, it is set that the second measurement circuit 4 is a large-voltage measurement circuit. When the voltage input by the fuse FUSE 1 is greater than the reference voltage VCC, the output of the operational amplifier OP1 as a voltage comparator is a high-level signal, that is, the voltage of the fuse FUSE 1 is measured by the second measurement circuit 4, and finally the measured voltage value is output via the resistor R10 and the diode D2.
[0049] When the voltage input by the fuse FUSE 1 is less than the reference voltage VCC, the output of the comparison circuit 2 flips. At this time, the output of the operational amplifier OP1 as a voltage comparator is a low-level signal. And the output level of the second measurement circuit 4 is still a high-level signal. At this time, a conduction voltage drop is generated on the diode D1, so the output of the second measurement circuit returns to the comparison circuit 2 again and does not output the measured voltage value via the resistor R10 and the diode D2. At this time, the voltage value of the fuse FUSE 1 is measured by the first measurement circuit 3, and finally the measured voltage value is output by the resistor R5 and the diode D3.
[0050] The above are only the embodiments of the present utility model and are not intended to limit the present utility model. For those skilled in the art, various modifications and variations can be made to the present utility model. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present utility model shall be included within the scope of the claims of the present utility model.
Claims
1. A new current sampling circuit, characterized in that: The invention comprises a fuse FUSE (1), a comparison circuit (2), a first measurement circuit (3), a second measurement circuit (4) and an anti-interference module (5), wherein the fuse FUSE (1) is electrically connected to the comparison circuit (2), the first measurement circuit (3) and the second measurement circuit (4) respectively, the comparison circuit (2) is electrically connected to the first measurement circuit (3), the second measurement circuit (4) and the anti-interference module (5) respectively, the first measurement circuit (3) is electrically connected to the second measurement circuit (4), and the second measurement circuit (4) is electrically connected to the anti-interference module (5), wherein the measurement ranges of the first measurement circuit (3) and the second measurement circuit (4) are different.
2. A new current sampling circuit according to claim 1, characterized in that: The comparison circuit (2) comprises a first comparison module (21), a first filtering module (22) and a second filtering module (23); the first comparison module (21) is electrically connected to the first filtering module (22) and the second filtering module (23), respectively; the first comparison module (21) is electrically connected to a fuse FUSE (1), a first measuring circuit (3), a second measuring circuit (4) and an anti-interference module (5), respectively.
3. A new current sampling circuit according to claim 2, characterized in that: The first comparison module (21) comprises an operational amplifier OP1, a reference power supply VCC and an input power supply VIN. The operational amplifier OP1 has a terminal 1, a terminal 2, a terminal 3, a terminal 4 and a terminal 5. The terminal 1 of the operational amplifier OP1 is electrically connected to the anti-interference module (5). The terminals 1 and 5 of the operational amplifier OP1 are connected in parallel with a first filtering module (22), and the terminal 5 is also electrically connected to a signal ground SGND. The terminal 2 of the operational amplifier OP1 is electrically connected to the reference power supply VCC. The terminal 3 of the operational amplifier OP1 is electrically connected to a fuse FUSE (1), a first measuring circuit (3) and a second comparison circuit (4) respectively. The terminal 4 of the operational amplifier OP1 is electrically connected to the input power supply VIN and a second filtering module (23) respectively.
4. A new current sampling circuit according to claim 2, characterized in that: The first filtering module (22) includes a capacitor C1, and the second filtering module (23) includes a capacitor C2. The capacitors C1 and C2 have a terminal 1 and a terminal 2 respectively. The terminal 1 and the terminal 2 of the capacitor C1 are electrically connected to the first comparing module (21); the terminal 1 of the capacitor C2 is electrically connected to the first comparing module (21), and the terminal 2 of the capacitor C2 is electrically connected to the signal ground SGND.
5. A novel current sampling circuit according to claim 1, characterized in that: The first measurement circuit (3) comprises a first protection module (31), a third filtering module (32), a first measurement module (33), a first feedback module (34) and a first output module (35); the first protection module (31) is electrically connected to a fuse FUSE (1), a comparison circuit (2), a second measurement circuit (4), a third filtering module (32), a second comparison module (33) and a first feedback module (34), respectively; the third filtering module (32) is electrically connected to the second comparison module (33), the second comparison module (33) is electrically connected to the first feedback module (34) and the first output circuit (35), respectively; and the first feedback module (34) is electrically connected to the output circuit (35).
6. A new type of current sampling circuit according to claim 5, characterized in that: The first protection module (31) comprises a resistor R1 and a resistor R2, wherein the resistor R1 and the resistor R2 have a terminal 1 and a terminal 2 respectively; The third filter module (32) includes a capacitor C3 and a resistor R4, wherein the capacitor C3 and the resistor R4 have a terminal 1 and a terminal 2 respectively, and the terminals 1 and 2 of the capacitor C3 and the resistor R4 are connected in parallel; The second comparison module (33) comprises an operational amplifier OP2, wherein the operational amplifier OP2 has a terminal 1, a terminal 2 and a terminal 3; The first feedback module (34) comprises a resistor R3 and a capacitor C4, wherein the resistor R3 and the capacitor C4 have a terminal 1 and a terminal 2 respectively, and the terminals 1 and 2 of the resistor R3 and the capacitor C4 are connected in parallel; The first output module (35) comprises a resistor R5 and a diode D3, wherein the resistor R5 and the diode D3 have a terminal 1 and a terminal 2 respectively; The end 1 of the resistor R1 is electrically connected to the fuse FUSE (1) and the second measuring circuit (3), and the end 2 of the resistor R1 is electrically connected to the end 1 of the resistor R3, the capacitor C4, and the end 2 of the operational amplifier OP2; the end 1 of the resistor R2 is electrically connected to the fuse FUSE (1), the comparison circuit (2), and the second measuring circuit (3), and the end 2 of the resistor R2 is electrically connected to the end 1 of the capacitor C3, the resistor R4, and the end 3 of the operational amplifier OP2; the capacitor C3 and the end 1 of the resistor R4 are electrically connected to the end 2 of the resistor R2; It is electrically connected to terminal No. 3 of the operational amplifier OP2, and terminal No. 2 of the capacitor C3 and the resistor R4 is electrically connected to the signal ground SGND; terminal No. 1 of the resistor R3 and the capacitor C4 is electrically connected to terminal No. 2 of the operational amplifier OP2, and terminal No. 2 of the resistor R3 and the capacitor C4 is electrically connected to terminal No. 1 of the operational amplifier OP2; terminal No. 1 of the resistor R5 is electrically connected to terminal No. 1 of the operational amplifier OP2, terminal No. 2 of the resistor R5 is electrically connected to terminal No. 1 of the diode D3, and terminal No. 2 of the diode D3 is electrically connected to the output terminal.
7. A novel current sampling circuit according to claim 1, characterized in that: The second measuring circuit (4) comprises a second protection module (41), a fourth filtering module (42), a second measuring module (43), a second feedback module (44) and a second output module (45); the second protection module (41) is electrically connected to the fuse FUSE (1), the comparison circuit (2), the first measuring circuit (3), the fourth filtering module (42), the third comparison module (43) and the second feedback module (44), respectively; the fourth filtering module (42) is electrically connected to the third comparison module (43); the third comparison module (43) is electrically connected to the second feedback module (44) and the second output module (45), respectively; and the second feedback module (44) is electrically connected to the output circuit (45).
8. A new type of current sampling circuit according to claim 6, characterized in that: The second protection module (41) comprises a resistor R6 and a resistor R7, wherein the resistor R6 and the resistor R7 have a terminal 1 and a terminal 2 respectively; The fourth filtering module (42) includes a capacitor C5 and a resistor R9, the capacitor C5 and the resistor R9 have a terminal 1 and a terminal 2 respectively, and the terminals 1 and 2 of the capacitor C5 and the resistor R9 are connected in parallel; The second comparison module (43) comprises an operational amplifier OP3, wherein the operational amplifier OP3 has a terminal 1, a terminal 2 and a terminal 3; The second feedback module (44) includes a resistor R8 and a capacitor C6, wherein the resistor R8 and the capacitor C6 have a terminal 1 and a terminal 2 respectively, and the terminals 1 and 2 of the resistor R8 and the capacitor C6 are connected in parallel; The second output module (45) includes a resistor R10 and a diode D2, wherein the resistor R10 and the diode D2 have a terminal 1 and a terminal 2 respectively; The No. 1 terminal of the resistor R6 is electrically connected to the fuse FUSE (1) and the first measuring circuit (3), respectively, and the No. 2 terminal of the resistor R6 is electrically connected to the No. 1 terminal of the resistor R8 and the No. 1 terminal of the capacitor C6 and the No. 2 terminal of the operational amplifier OP3; the No. 1 terminal of the resistor R7 is electrically connected to the fuse FUSE, the comparison circuit (2) and the first measuring circuit (3), respectively, and the No. 2 terminal of the resistor R7 is electrically connected to the No. 1 terminal of the capacitor C5 and the No. 1 terminal of the resistor R9 and the No. 3 terminal of the operational amplifier OP3; the No. 1 terminal of the capacitor C5 and the No. 1 terminal of the resistor R9 is electrically connected to the No. 1 terminal of the operational amplifier OP3; the No. 1 terminal of the capacitor C5 and the No. 1 terminal of the resistor R9 is electrically connected to the No. 1 terminal of the operational amplifier OP3; the No. 1 terminal of the resistor R7 ... Terminal No. 3 of amplifier OP3 is electrically connected, and terminal No. 2 of capacitor C5 and resistor R9 is electrically connected to signal ground SGND; terminal No. 1 of resistor R8 and capacitor C6 is electrically connected to terminal No. 2 of operational amplifier OP3, and terminal No. 2 of resistor R8 and capacitor C6 is electrically connected to terminal No. 1 of operational amplifier OP3; terminal No. 1 of resistor R10 is electrically connected to terminal No. 1 of operational amplifier OP3, terminal No. 2 of resistor R10 is electrically connected to terminal No. 1 of diode D2, and terminal No. 2 of diode D2 is electrically connected to the output terminal.
9. A novel current sampling circuit according to claim 1, characterized in that: The anti-interference module (5) comprises a diode D1, the diode D1 has a terminal 1 and a terminal 2, the terminal 1 of the diode D1 is electrically connected to the second measurement circuit (4), and the terminal 1 of the diode D1 is electrically connected to the comparison circuit (2).