Current acquisition board card and multichannel current acquisition board card

Abstract

The utility model relates to the technical field of current detection, and discloses a current acquisition board card and a multichannel current acquisition board card, comprising a power supply conversion module used for carrying out voltage conversion on a power supply and outputting a plurality of power supply voltages; the switching module is used for conducting the first current detection module or the second current detection module based on the switching enable signal; the first current detection module is connected with the power supply conversion module, the switching module and the to-be-collected circuit, and is used for carrying out current collection within a first current amplitude range on the to-be-collected circuit after the first current detection module is switched on; and the second current detection module is connected with the power supply conversion module, the switching module, the first current detection module and the to-be-acquired circuit, and is used for performing current acquisition in a second current amplitude range on the to-be-acquired circuit after conduction. According to the utility model, the integration level of the current acquisition board card can be improved, the wide-range current detection range is covered, equipment does not need to be replaced when current measurement is carried out in different working states, and the current detection cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to current detection technical field, concretely relates to a current acquisition board card and multichannel current acquisition board card. BACKGROUND

[0002] With the rapid development of automobile electronic technology, the requirement of automobile controller power consumption and the requirement of power quality and energy efficiency are higher and higher, and the power consumption of automobile controller in the sleep state is usually required to be generally in the micro watt (muW) to milliwatt (mW) level. Therefore, by accurately measuring the current of the controller in various working states, power management, fault diagnosis and protection measures can be more efficient.

[0003] At present, most current acquisition board cards cannot cover the wide range of current detection, especially in the application of measuring from small current to high current at the same time, usually the large current and small current are detected by two devices separately, so the measuring device needs to be replaced when the current amplitude changes greatly each time, the work efficiency is not high, and the disadvantages of some products that need to monitor the current in real time are obvious. Secondly, using two current acquisition board cards with different ranges will significantly increase the cost. SUMMARY

[0004] Therefore, the utility model provides a current acquisition board card and multichannel current acquisition board card to solve the problem that high current and small current cannot be detected by using the same current acquisition board card.

[0005] In the first aspect, the utility model provides a current acquisition board card, which comprises: a power conversion module, a switching module, a first current detection module and a second current detection module; wherein the power conversion module is used for voltage conversion of the power supply, and outputs multiple power supply voltages; the switching module is connected with the power conversion module, and is used for turning on the first current detection module or the second current detection module based on the received switching enable signal; the first current detection module is connected with the power conversion module, the switching module and the circuit to be collected, and is used for collecting the current in the first current amplitude range of the circuit to be collected after being turned on; the second current detection module is connected with the power conversion module, the switching module, the first current detection module and the circuit to be collected, and is used for collecting the current in the second current amplitude range of the circuit to be collected after being turned on.

[0006] The current acquisition board provided by the utility model, through the power conversion module, voltage conversion is carried out to the power supply, and multiple power supply voltages are provided for the switching module, the first current detection module and the second current detection module, the switching module turns on the first current detection module or the second current detection module according to the switching enable signal, and the first current detection module or the second current detection module carries out current acquisition of different current amplitude ranges to the circuit to be collected after being turned on. The utility model integrates different current detection modules on the same board, can improve the integration of the current acquisition board, covers the wide-range current detection range, realizes the accurate acquisition of the large current and the microampere level current, and does not need to replace the equipment when the current measurement is carried out to the different working states of the circuit to be collected, so that the current detection cost is reduced.

[0007] In an alternative embodiment, the power conversion module comprises: a voltage stabilizing and filtering unit for stabilizing voltage and filtering noise of the power supply, outputting a first power supply voltage; a first voltage conversion unit connected with the voltage stabilizing and filtering unit, for voltage conversion of the first power supply voltage, outputting a second power supply voltage; and a second voltage conversion unit connected with the first voltage conversion unit, for voltage conversion of the second power supply voltage, outputting a third power supply voltage.

[0008] The utility model can provide different power supply voltages for the integrated modules of the current acquisition board by the hierarchical conversion of the voltage of the power supply, ensure that each stage works at its highest efficiency point, thereby improve the efficiency of the whole system, and can also more accurately regulate and control the output voltage in order to meet the needs of different loads.

[0009] In an alternative embodiment, the switching module comprises: a switching enable signal input unit connected with the voltage stabilizing and filtering unit, for turning on or turning off the input of the switching enable signal based on an external detection control signal under the power supply of the first power supply voltage; a circuit switching unit connected with the switching enable signal input unit, for turning on the first current detection module or the second current detection module based on the switching enable signal; and a reference voltage input unit connected with the first voltage conversion unit, for stabilizing voltage of the second power supply voltage, obtaining a reference voltage.

[0010] The utility model can control the input of the switching enable signal according to the external input detection control signal through the switching module, thereby turning on different current detection modules through circuit switching, realizing the accurate acquisition of the large current and the microampere level current. Meanwhile, the reference voltage is provided for the current detection, which can calibrate and adjust the measurement results to a certain extent, so as to ensure the accuracy of the current measurement.

[0011] In one optional implementation, the first current detection module includes: a first current detection unit connected to a second voltage conversion unit, a switching module, and a circuit to be acquired, used to perform a first current detection on the circuit to be acquired when it is turned on under a third power supply voltage; and a first operational amplifier unit connected to the first current detection unit and the first voltage conversion unit, used to amplify the analog signal of the first current detection under a second power supply voltage and output the current detection result.

[0012] This invention, through the first current detection module of the current acquisition board, can ensure the accuracy and precision of data acquisition even under low current conditions, thus meeting the detection requirements.

[0013] In one optional implementation, the second current detection module includes: a second current detection unit connected to the second voltage conversion unit, the first current detection unit, and the circuit to be acquired, for performing a second current detection on the circuit to be acquired when it is turned on under the third power supply voltage; and a second operational amplifier unit connected to the second current detection unit and the first voltage conversion unit, for amplifying the analog signal of the second current detection under the second power supply voltage and outputting the current detection result.

[0014] This invention, through the second current detection module of the current acquisition board, can ensure the accuracy and precision of the acquisition under high current conditions, further meeting the detection requirements, and there is no need to switch the current acquisition device during the detection process.

[0015] In one optional embodiment, the voltage regulation and filtering unit includes: an input terminal of a power supply, the input terminal of which is connected to the first terminal of a first diode and the first terminal of a second diode; the second terminal of the first diode is connected to the first terminal of a first inductor and the first terminal of a first capacitor; the second terminal of the first inductor is connected to the first terminal of a second capacitor, the first terminal of a third capacitor, the first terminal of a fourth capacitor, the output terminal of a first power supply voltage, and the first terminal of a first resistor; the second terminal of the first resistor is connected to the first terminal of a power indicator light; and the second terminal of the second diode, the second terminal of the first capacitor, the second terminal of the second capacitor, the second terminal of the third capacitor, the second terminal of the fourth capacitor, and the second terminal of the power indicator light are connected to a ground point; the first voltage conversion unit includes: a power management integrated circuit, the power management integrated circuit... The first terminal of the circuit is connected to the output terminal of the first supply voltage. The second terminal of the power management integrated circuit is connected to the first terminal of the fifth capacitor, the first terminal of the sixth capacitor, and the output terminal of the second supply voltage. The third terminal of the power management integrated circuit, the second terminal of the fifth capacitor, and the second terminal of the sixth capacitor are connected to the ground point. The second voltage conversion unit includes: a low dropout regulator. The first terminal of the low dropout regulator is connected to the output terminal of the second supply voltage and the first terminal of the second resistor. The second terminal of the low dropout regulator is connected to the second terminal of the second resistor and the first terminal of the seventh capacitor. The third terminal of the low dropout regulator is connected to the first terminal of the eighth capacitor, the first terminal of the ninth capacitor, and the output terminal of the third supply voltage. The second terminals of the seventh capacitor, the eighth capacitor, and the ninth capacitor are connected to the ground point.

[0016] This invention utilizes a combination of inductors and capacitors to form an LC filter, removing specific frequency signals from the circuit while also filtering out high-frequency noise and protecting the stability of the power supply circuit. Furthermore, by deploying capacitors at the output terminals of different supply voltages, the stability of the power supply can be guaranteed, enabling graded voltage conversion of the power supply.

[0017] In one optional embodiment, the switching enable signal input unit includes: an optocoupler, wherein a first terminal of the optocoupler's light-emitting side is connected to a first terminal of an external detection control signal, a second terminal of the light-emitting side is connected to a first terminal of a third resistor, a second terminal of the third resistor is connected to a second terminal of the external detection control signal, a first terminal of the optocoupler's light-receiving side is connected to a first terminal of a fourth resistor, and a second terminal of the fourth resistor is connected to an output terminal of a first power supply voltage; the circuit switching unit includes: a relay, wherein a first terminal of the relay is connected to an output terminal of a second power supply voltage, a first terminal of a first switching diode is connected, a second terminal of the relay is connected to a first terminal of a fifth resistor, and a second terminal of the fifth resistor is connected to an output terminal of the first switching diode. The second terminal of the switching diode is connected to the first terminal of the second switching diode. The second terminal of the second switching diode is connected to the first terminal of the sixth resistor. The second terminal of the sixth resistor is connected to the second terminal of the light-receiving side of the optocoupler. The third terminal of the second switching diode is connected to the ground point. The third terminal of the relay is connected to the first terminal of the circuit to be acquired and the first terminal of the tenth capacitor. The second terminal of the tenth capacitor is connected to the ground point. The reference voltage input unit includes: a voltage reference chip. The first terminal of the voltage reference chip is connected to the first terminal of the seventh resistor and the first terminal of the eighth resistor. The second terminal of the seventh resistor is connected to the output terminal of the second supply voltage. The second terminal of the eighth resistor and the second terminal of the voltage reference chip are connected to the ground point.

[0018] This invention, by deploying an optocoupler, provides electrical isolation between the input and output based on the control switching enable signal input. This largely filters out electromagnetic and radio frequency interference from the input and output circuits, effectively improving the accuracy of the acquired signal and the reliability of the acquisition board. Simultaneously, by deploying relays, different current detection circuits can be activated according to the switching enable signal, enabling the acquisition of large or small currents without requiring replacement of the acquisition equipment, thus simplifying the current detection process under different operating conditions. Furthermore, the deployment of a voltage reference chip provides a reference voltage for current acquisition. Connecting the reference voltage input to the internal gain network allows for calibration and adjustment of the measurement results to a certain extent, ensuring the accuracy of the current measurement.

[0019] In one optional embodiment, the first current detection unit includes: a first current detection amplifier, a first terminal of which is connected to the third terminal of the relay of the switching module and the first terminal of the first sampling resistor; a second terminal of which is connected to the second terminal of the first sampling resistor and the fourth terminal of the relay; a third terminal of which is connected to the first terminal of the eleventh capacitor and the output terminal of the third supply voltage; a fourth terminal of which is connected to the first terminal of the ninth resistor; a second terminal of the ninth resistor is connected to the first terminal of the twelfth capacitor; and a fifth and a sixth terminal of which are connected to the voltage reference of the switching module. The first terminal of the chip is connected to the first terminal of the thirteenth capacitor, and the second terminals of the eleventh, twelfth, and thirteenth capacitors are connected to the ground point; the first operational amplifier unit: the first operational amplifier, the first terminal of the first operational amplifier is connected to the second terminal of the ninth resistor, the second terminal of the first operational amplifier is connected to the first terminal of the tenth and eleventh resistors, the third terminal of the first operational amplifier is connected to the second terminal of the eleventh resistor and the first terminal of the twelfth resistor, the second terminal of the twelfth resistor is connected to the first terminal of the fourteenth capacitor and the first current detection result output terminal, and the second terminals of the tenth resistor and the fourteenth capacitor are connected to the ground point.

[0020] This invention, by deploying a first sampling resistor in the first current detection module, enables precise acquisition of microampere-level small currents by combining a current detection amplifier and an operational amplifier after the first sampling resistor is turned on, thus meeting the user's detection needs.

[0021] In one optional embodiment, the second current detection unit includes: a second current detection amplifier, the first terminal of which is connected to the first terminal of a second sampling resistor; the second terminal of which is connected to the second terminal of the second sampling resistor, the first terminal of a first sampling resistor, the fourth terminal of a relay, the first terminal of a fifteenth capacitor, and the second terminal of the circuit to be sampled; the third terminal of which is connected to the first terminal of a sixteenth capacitor and the output terminal of a third supply voltage; the fourth terminal of which is connected to the first terminal of a thirteenth resistor; the second terminal of the thirteenth resistor is connected to the first terminal of a seventeenth capacitor; the fifth and sixth terminals of which are connected to the first terminal of a voltage reference chip and the first terminal of an eighteenth capacitor; and the second terminal of the fifteenth capacitor... The second terminals of the sixteenth, seventeenth, and eighteenth capacitors are connected to the ground point; the second operational amplifier unit includes: a second operational amplifier, the first terminal of which is connected to the second terminal of the thirteenth resistor, the second terminal of which is connected to the first terminals of the fourteenth and fifteenth resistors, the third terminal of which is connected to the second terminal of the fifteenth resistor and the first terminal of the sixteenth resistor, the second terminal of the sixteenth resistor is connected to the first terminal of the nineteenth capacitor and the second current detection result output terminal, the power supply terminal of the second operational amplifier is connected to the output terminal of the second supply voltage and the first terminal of the twentieth capacitor, and the ground terminal of the fourteenth resistor, the nineteenth capacitor, the twentieth capacitor, and the second operational amplifier are connected to the ground point.

[0022] This invention deploys a second sampling resistor in the second current detection module, which can conduct when the first sampling resistor is short-circuited. Combined with the current detection amplifier and operational amplifier, it achieves accurate acquisition of large currents without the need to replace the current acquisition equipment, meeting user detection needs and improving the integration and flexibility of the current acquisition board.

[0023] Secondly, this utility model provides a multi-channel current acquisition board, including: a power conversion module, and an equal number of switching modules, a first current detection module, and a second current detection module.

[0024] The multi-channel current acquisition board provided by this utility model provides different voltage power supplies to other modules through an integrated power conversion module. The same number of switching modules, the first current acquisition module and the second current acquisition module form different current acquisition channels, which can realize the simultaneous acquisition of multiple channels. Each channel is independent of each other, providing users with greater flexibility in current acquisition. It can also further improve the integration of the board and reduce the complexity and size of the system. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a schematic diagram of the structure of a current acquisition board according to an embodiment of the present utility model;

[0027] Figure 2 This is a circuit diagram of the power conversion module of a current acquisition board according to an embodiment of the present utility model;

[0028] Figure 3 This is a circuit diagram of a switching module of a current acquisition board according to an embodiment of the present utility model;

[0029] Figure 4 This is a circuit diagram of the first current detection module of a current acquisition board according to an embodiment of the present utility model;

[0030] Figure 5 This is a circuit diagram of the second current detection module of a current acquisition board according to an embodiment of the present utility model;

[0031] Figure 6 This is a schematic diagram of the overall circuit of a current acquisition board according to an embodiment of the present utility model;

[0032] Figure 7 This is a schematic diagram of the structure of a multi-channel current acquisition board according to an embodiment of the present invention;

[0033] Explanation of reference numerals in the attached figures:

[0034] 100 - Power conversion module; 101 - Voltage regulation and filtering unit; 102 - First voltage conversion unit; 103 - Second voltage conversion unit; 200 - Switching module; 201 - Switching enable signal input unit; 202 - Circuit switching unit; 203 - Reference voltage input unit; 300 - First current detection module; 301 - First current detection unit; 302 - First operational amplifier unit; 400 - Second current detection module; 401 - Second current detection unit; 402 - Second operational amplifier unit. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0036] This invention is applicable to scenarios where current detection is performed on circuits under various operating conditions, such as dynamic current monitoring of circuits with large differences in current amplitude. The following is a combination of... Figures 1 to 7 The following describes embodiments of the present invention.

[0037] According to an embodiment of the present invention, in one aspect, a current acquisition board is provided, such as... Figure 1 As shown, the system includes: a power conversion module 100, a switching module 200, a first current detection module 300, and a second current detection module 400. The power conversion module 100 is used to convert the power supply voltage and output multiple power supply voltages. The switching module 200 is connected to the power conversion module 100 and is used to activate either the first current detection module 300 or the second current detection module 400 based on a received switching enable signal. The first current detection module 300 is connected to the power conversion module 100, the switching module 200, and the circuit to be sampled, and is used to sample the current within a first current amplitude range of the circuit to be sampled after activation. The second current detection module 400 is connected to the power conversion module 100, the switching module 200, the first current detection module 300, and the circuit to be sampled, and is used to sample the current within a second current amplitude range of the circuit to be sampled after activation.

[0038] Specifically, in the embodiments of this utility model, such as Figure 2 As shown, the power conversion module 100 includes: a voltage stabilizing and filtering unit 101, used to stabilize the power supply and filter out noise, and output a first power supply voltage; a first voltage conversion unit 102, connected to the voltage stabilizing and filtering unit 101, used to convert the first power supply voltage and output a second power supply voltage; and a second voltage conversion unit 103, connected to the first voltage conversion unit 102, used to convert the second power supply voltage and output a third power supply voltage.

[0039] In some alternative implementations, such as Figure 2As shown, the voltage regulator and filter unit 101 includes: an input terminal of the power supply V_PWR, which is connected to the first terminal of the first diode S2J and the first terminal of the second diode D101. The S2J added at the input terminal of the power supply V_PWR serves to prevent reverse connection. The second diode D101 connected in parallel is a transient suppression diode SMBJ33CA, whose main function is to absorb transient overvoltage surges, maintain the stability of the input power supply voltage, and shun excess voltage to ground, protecting the stability of the power input and other components in the circuit from damage. The second terminal of the first diode S2J is connected to the first terminal of the first inductor L101 and the first terminal of the first capacitor C101. The second terminal of the first inductor L101 is connected to the first terminals of the second capacitor C102, the third capacitor C103, the fourth capacitor C104, the output terminal of the first supply voltage VCC240, and the first terminal of the first resistor R101. At this point, L101 connected in series near the power supply V_PWR and C101, C102, and C103 connected in parallel form an LC filter. Its main function is to remove specific frequency signals from the circuit, while also filtering out high-frequency noise and protecting the stability of the power supply circuit. Meanwhile, C104, connected in parallel with the first power supply voltage VCC240, is a large capacitor used to ensure the stability of the 24V power supply output from the VCC240 port. The second terminal of the first resistor R101 is connected to the first terminal of the power indicator D103. R101's main function is current limiting, and D103 is an LED light, primarily used for power indication. Furthermore, the second terminals of the second diode D101, the first capacitor C101, the second capacitor C102, the third capacitor C103, the fourth capacitor C104, and the power indicator D103 are connected to ground.

[0040] In some alternative implementations, such as Figure 2 As shown, the first voltage conversion unit 102 includes a power management integrated circuit U101. The first terminal of the power management integrated circuit U101 is connected to the output terminal of the first supply voltage VCC240. The second terminal of the power management integrated circuit U101 is connected to the first terminal of the fifth capacitor C105, the first terminal of the sixth capacitor C106, and the output terminal of the second supply voltage VCC120. The third terminal of the power management integrated circuit U101, the second terminal of the fifth capacitor C105, and the second terminal of the sixth capacitor C106 are connected to a ground point. The power management integrated circuit U101 is an MC7812BDTG, and its main function is to convert the 24V input voltage into a stable 12V output. The main functions of C105 and C106 are to filter out noise interference and ensure the stability of the 12V power supply output.

[0041] In some alternative implementations, such as Figure 2As shown, the second voltage conversion unit 103 includes: a low-dropout regulator U102. The first terminal of the low-dropout regulator U102 is connected to the output terminal of the second supply voltage VCC120 and the first terminal of the second resistor R102. The second terminal of the low-dropout regulator U102 is connected to the second terminal of the second resistor R102 and the first terminal of the seventh capacitor C107. The third terminal of the low-dropout regulator U102 is connected to the first terminal of the eighth capacitor C108, the first terminal of the ninth capacitor C109, and the output terminal of the third supply voltage VCC50. The second terminals of the seventh capacitor C107, the eighth capacitor C108, and the ninth capacitor C109 are connected to ground. The low-dropout regulator U102 is a TLE42664G, used to convert the converted 12V voltage back to a 5V output supply voltage. The main functions of R102 and C107 are current limiting and filtering, while the main functions of C108 and C109 are filtering out noise interference to ensure the stability of the 5V power supply output. This invention, through graded voltage conversion, ensures that each stage operates at its highest efficiency point, thereby improving the efficiency of the entire system. At the same time, it also allows for more precise control of the output voltage to meet the needs of different loads.

[0042] In some alternative implementations, such as Figure 3 and Figure 4 As shown, the switching module 200 includes: a switching enable signal input unit 201, connected to the voltage regulation and filtering unit 101, used to turn on or off the input of the switching enable signal based on an external detection control signal under the first supply voltage; a circuit switching unit 202, connected to the switching enable signal input unit 201, used to turn on the first current detection module 300 or the second current detection module 400 based on the switching enable signal; and a reference voltage input unit 203, connected to the first voltage conversion unit 102, used to regulate the second supply voltage to obtain a reference voltage.

[0043] In some alternative implementations, such as Figure 3As shown, the switching enable signal input unit 201 includes: an optocoupler U201. The first terminal of the light-emitting side of the optocoupler U201 is connected to the first terminal of the external detection control signal CTL_CH0. The second terminal of the light-emitting side is connected to the first terminal of the third resistor R213. The second terminal of the third resistor R213 is connected to the second terminal of the external detection control signal CTL_COM. The first terminal of the light-receiving side of the optocoupler U201 is connected to the first terminal of the fourth resistor R203. The second terminal of the fourth resistor R203 is connected to the output terminal of the first supply voltage VCC240. The optocoupler U201 is a PS2801-4 / SM, and R203 is a current-limiting resistor. The first supply voltage VCC240 provides power to the circuit switching unit 202 through the current-limiting resistor and the optocoupler PS2801-4 / SM. The primary function of the optocoupler PS2801-4 / SM is to provide electrical isolation between the input and output, effectively filtering out electromagnetic interference (EMI) and radio frequency interference (RFI) from the input and output circuits, thus significantly improving the accuracy of the acquired signal and the reliability of the acquisition board. R213's main function is current limiting. The voltage adjustment at the CTL_CH0 and CTL_COM ports controls the switching on and off of the optocoupler PS2801-4 / SM, thereby controlling the transmission of the switching module's enable signal, RELAY.

[0044] In some alternative implementations, such as Figure 4As shown, the circuit switching unit 202 includes: a relay T301, the first terminal of which is connected to the output terminal of the second power supply voltage VCC120, the first terminal of the first switching diode D301, the second terminal of which is connected to the first terminal of the fifth resistor R303, the second terminal of the fifth resistor R303, the second terminal of which is connected to the second terminal of the first switching diode D301 and the first terminal of the second switching diode Q1, the second terminal of the second switching diode Q1, the first terminal of the sixth resistor R304, the second terminal of the sixth resistor R304, and the second terminal of the optocoupler U201 (the light-receiving side), the third terminal of the second switching diode Q1, and the third terminal of the relay T301, which is connected to the first terminal of the circuit to be acquired and the first terminal of the tenth capacitor C301, and the second terminal of the tenth capacitor C301, which is connected to the ground. The relay T301 is an HFKC1Z, and the first switching diode D301 is a BAV70LT1G. The main function of R303 and R304 is current limiting. The switching diode BAV70LT1G enables current switching control in a circuit, allowing current to flow in both directions. It automatically disconnects when the voltage exceeds its rated value, protecting the circuit. During current detection, when the current falls below a set threshold, the switching enable signal input unit 201 outputs a switching enable signal RELAY. When the switching diode BAV70LT1G receives the RELAY signal, the circuit is turned on, and the relay HFKC1Z switches from contact 3 to contact 5. When the current increases beyond the threshold, the switching enable signal RELAY stops outputting, and the relay HFKC1Z returns to contact 3.

[0045] In some alternative implementations, such as Figure 3 As shown, the reference voltage input unit 203 includes: a voltage reference chip D201. The first terminal of the voltage reference chip D201 is connected to the first terminal of the seventh resistor R201 and the first terminal of the eighth resistor R202. The second terminal of the seventh resistor R201 is connected to the output terminal of the second supply voltage VCC120. The second terminal of the eighth resistor R202 and the second terminal of the voltage reference chip D201 are connected to ground. The voltage reference chip D201 is an LM4050QAEM3-5 / NOPB. R201 and R202 are voltage divider resistors. The second supply voltage VCC120 is divided by these resistors. Simultaneously, the LM4050QAEM3-5 / NOPB is connected in parallel across R202 to output a stable 12V voltage as a reference voltage, which is then input to the REF1 and REF2 pins in the subsequent first and second current detection modules. The output voltage is set by applying one or more voltages to the REF1 and REF2 pins. This invention will... Figure 2The voltage generated by the power conversion module 100 is connected to the internal gain network as a reference voltage input. By selecting different voltages generated by the power conversion module 100 as the adjustment reference voltage, the measurement results can be calibrated and adjusted to a certain extent to ensure the accuracy of the current measurement.

[0046] In some alternative implementations, such as Figure 4 As shown, the first current detection module 300 includes: a first current detection unit 301, connected to the second voltage conversion unit 103, the switching module 200 and the circuit to be acquired, used to perform a first current detection on the circuit to be acquired when it is turned on under the third power supply voltage; and a first operational amplifier unit 302, connected to the first current detection unit 301 and the first voltage conversion unit 102, used to amplify the analog signal of the first current detection under the second power supply voltage and output the current detection result.

[0047] In some alternative implementations, such as Figure 4 As shown, the first current detection unit 301 includes: a first current detection amplifier U301, the first terminal of the first current detection amplifier U301 is connected to the third terminal of the relay T301 of the switching module 200 and the first terminal of the first sampling resistor R301, the second terminal of the first current detection amplifier U301 is connected to the second terminal of the first sampling resistor R301 and the fourth terminal of the relay T301, the third terminal of the first current detection amplifier U301 is connected to the first terminal of the eleventh capacitor C303 and the output terminal of the third power supply voltage VCC50, the fourth terminal of the first current detection amplifier U301 is connected to the first terminal of the ninth resistor R305, the second terminal of the ninth resistor R305 is connected to the first terminal of the twelfth capacitor C307, the fifth and sixth terminals of the first current detection amplifier U301 are connected to the first terminal of the voltage reference chip D201 of the switching module 200 and the first terminal of the thirteenth capacitor C304, and the second terminals of the eleventh capacitor C303, the twelfth capacitor C307 and the thirteenth capacitor C304 are connected to the ground point. Among them, the first current detection amplifier U301 is INA240A3QPWRQ1, with Figure 2The 5V converted by the power conversion module is connected to the VS pin as the supply voltage. The main function of C303 connected in parallel to the supply voltage pin is to filter and ensure the stability of the supply voltage, enabling accurate detection of the current direction and magnitude. R301 is a large resistor; after the current flows through the sampling resistor, the voltage across the sampling resistor is collected and input to the IN+ and IN- pins of the first current sensing amplifier U301. Pins REF1 and REF2 are the reference voltage input pins of the first current sensing amplifier U301. The main function of C304 is to filter and ensure input stability. The OUT pin of the first current sensing amplifier U301 outputs the analog signal after current detection processing; the output analog signal is proportional to the current flowing through the first sampling resistor R301. Circuit switching unit 202 uses... Figure 2 The 12V voltage from the intermediate converter serves as the power supply voltage. Under normal conditions, the first sampling resistor R301 is short-circuited, and the low-current detection circuit is inactive. When the current drops to the threshold, the relay HFKC1Z switches from contact 3 to contact 5, allowing current to flow through the first sampling resistor R301, and the low-current sampling circuit begins to operate. The low-current detection circuit increases the resistance of the first sampling resistor R301, ensuring accuracy and precision in data acquisition even with low current.

[0048] In some optional embodiments, the first operational amplifier unit 302 is a first operational amplifier U303-1. The first terminal of the first operational amplifier U303-1 is connected to the second terminal of the ninth resistor R305. The second terminal of the first operational amplifier U303-1 is connected to the first terminals of the tenth resistor R307 and the eleventh resistor R309. The third terminal of the first operational amplifier U303-1 is connected to the second terminal of the eleventh resistor R309 and the first terminal of the twelfth resistor R311. The second terminal of the twelfth resistor R311 is connected to the first terminal of the fourteenth capacitor C310 and the first current detection result output terminal AD0. The second terminals of the tenth resistor R307 and the fourteenth capacitor C310 are connected to ground. The first operational amplifier U303-1 is a TLV272IDR, whose main function is to isolate the preceding and following circuits, prevent mutual interference between circuits, and prevent changes in gain and phase. Simultaneously, the first operational amplifier U303-1 employs negative feedback regulation to reduce nonlinear distortion and improve the quality of the output analog signal. The main functions of R307 and R309 are current limiting and voltage division. The RC filter circuit composed of R311 and C310 can make the output analog signal more stable and reliable.

[0049] In some alternative implementations, such as Figure 5As shown, the second current detection module 400 includes: a second current detection unit 401, connected to the second voltage conversion unit 103, the first current detection unit 301, and the circuit to be acquired, used to perform a second current detection on the circuit to be acquired when it is turned on under the third power supply voltage; and a second operational amplifier unit 402, connected to the second current detection unit 401 and the first voltage conversion unit 102, used to amplify the analog signal of the second current detection under the second power supply voltage and output the current detection result.

[0050] In some alternative implementations, such as Figure 5 As shown, the second current detection unit 401 includes: a second current detection amplifier U302, the first terminal of which is connected to the first terminal of the second sampling resistor R302; the second terminal of which is connected to the second terminal of the second sampling resistor R302, the first terminal of the first sampling resistor R301, the fourth terminal of the relay T301, the first terminal of the fifteenth capacitor C302, and the second terminal of the circuit to be sampled; and the third terminal of which is connected to the first terminal of the sixteenth capacitor C305 and the third power supply voltage. The output terminal of VCC50 is connected. The fourth terminal of the second current sensing amplifier U302 is connected to the first terminal of the thirteenth resistor R306. The second terminal of the thirteenth resistor R306 is connected to the first terminal of the seventeenth capacitor C308. The fifth and sixth terminals of the second current sensing amplifier U302 are connected to the first terminals of the voltage reference chip D201 and the first terminal of the eighteenth capacitor C306. The second terminals of the fifteenth capacitor C302, the sixteenth capacitor C305, the seventeenth capacitor C308, and the eighteenth capacitor C306 are connected to the ground point. The second current sensing amplifier U302 is an INA240A3QPWRQ1, which functions similarly to the first current sensing unit, except that the second sampling resistor R302 is a small resistor. When the relay HFKC1Z returns to contact 3, R301 is short-circuited, and current flows through the sampling resistor R302, at which point the high-current sampling circuit begins to operate.

[0051] In some alternative implementations, such as Figure 5As shown, the second operational amplifier unit 402 includes: a second operational amplifier U303-2, the first terminal of the second operational amplifier U303-2 is connected to the second terminal of the thirteenth resistor R306, the second terminal of the second operational amplifier U303-2 is connected to the first terminal of the fourteenth resistor R308 and the first terminal of the fifteenth resistor R310, the third terminal of the second operational amplifier U303-2 is connected to the second terminal of the fifteenth resistor R310 and the first terminal of the sixteenth resistor R312, the second terminal of the sixteenth resistor R312 is connected to the first terminal of the nineteenth capacitor C311 and the second current detection result output terminal AD1, the power supply terminal of the second operational amplifier U303-3 is connected to the output terminal of the second power supply voltage VCC120 and the first terminal of the twentieth capacitor C309, the second terminal of the fourteenth resistor R308, the second terminal of the nineteenth capacitor C311, the second terminal of the twentieth capacitor C309 and the ground terminal of the second operational amplifier U303 are connected to the grounding point. The second operational amplifier unit 402 is a TLV272IDR, which functions similarly to the first current detection unit. The second operational amplifier unit 402 uses... Figure 2 The 12V output from the power module is connected to the VCC pin as the supply voltage. C309's main function is filtering and ensuring input stability. Additionally, as... Figure 4 and Figure 5 As shown, C301 and C302 connected in parallel at the current inflow and outflow pins can filter out noise interference.

[0052] In some alternative implementations, such as Figure 6 As shown, the first current detection module 300 and the second current detection module 400 are connected together to form a single-channel current detection circuit schematic. The current detection amplifier INA240A3QPWRQ1 in both current detection circuits utilizes two sampling resistors with different resistance values: R301 and R302, to convert the current signal into a voltage-type analog signal that can be processed and recognized by the operational amplifier TLV272IDR. After amplification by the operational amplifier, a stable analog signal that can be identified and calculated is obtained. Selecting the sampling circuit based on whether the acquired current exceeds a set threshold can significantly improve the accuracy of current acquisition and expand the application scenarios of the current acquisition board.

[0053] The current acquisition board provided by this utility model uses a power conversion module to convert the power supply voltage, providing different power supply voltages to the switching module, the first current detection module, and the second current detection module. The switching module activates either the first or second current detection module based on a switching enable signal. After activation, the first or second current detection module acquires current from the circuit under test for different current amplitude ranges. By integrating different current detection modules on the same board, this utility model improves the integration of the current acquisition board, covers a wide current detection range, and achieves accurate acquisition of large currents and microamp-level currents. When measuring current in different operating states of the circuit under test, no equipment replacement is required, thereby reducing current detection costs.

[0054] According to an embodiment of this utility model, another aspect also provides a multi-channel current acquisition board, such as... Figure 7 As shown, it includes: a power conversion module 100, and the same number of switching modules 200, a first current detection module 300, and a second current detection module 400.

[0055] Specifically, in this embodiment of the invention, the multi-channel current acquisition board consists of three... Figure 6 The example consists of isolated single-channel current acquisition channels, and is not intended to limit the scope of this example. Figure 7 As shown, the multi-channel current acquisition board deploys three switching modules 200, each corresponding to a specific configuration. Figure 3 and Figure 6 The circuit is connected to the first current detection module 300 and the second current detection module 400 to form a single-channel current acquisition channel. Each single channel includes an INA240A3QPWRQ1 current detection amplifier and a TLV272IDR operational amplifier. The INA240A3QPWRQ1 current detection amplifier can accurately detect the direction and magnitude of the current and transmit the acquired analog signal to the operational amplifier module for processing. The TLV272IDR operational amplifier can amplify the acquired analog signal and also isolate the input and output. Integrating multiple channels and other functions into a compact circuit board reduces the complexity and size of the system and improves integration and reliability. The three current acquisition channels are independent of each other, capable of acquiring and uploading current independently, and can simultaneously acquire the current values ​​of multiple channels in real time, providing greater flexibility.

[0056] In some optional implementations, the multi-channel high-precision current acquisition board provided by this invention can simultaneously support multiple current detections, is compatible with both high-current and microampere-level current detection, can quickly respond to current changes, is suitable for dynamic current monitoring, and is applicable to applications with rapid current changes and large current amplitude differences. Furthermore, this current acquisition board has electrical isolation to protect the measurement system and operator safety. The current detection board features a modular design, making it easy to integrate into existing electronic systems and also facilitates expansion of communication interfaces with external devices, including USB, RS-485, and CAN. In addition, the analog signal output by the current detection board, after processing, can directly display the specific current value on an LCD or LED display. Simultaneously, this current acquisition board also features a wide common-mode range, high precision, zero-drift topology, excellent common-mode rejection ratio (CMRR), and enhanced pulse width modulation (PWM) suppression. Enhanced PWM can significantly suppress the impact of common-mode transients on the output signal related to the PWM signal.

[0057] This invention provides a multi-channel current acquisition board capable of handling common-mode voltages up to 80V and operating at -4V, enabling stable performance in various power supply environments. Simultaneously, the board's acquisition module provides extremely low gain error and offset voltage, ensuring high accuracy in current measurement. A control circuit switching unit enables the acquisition of both high-current and microamp-level currents, ensuring high accuracy. The highly integrated design combines multiple channels and other functions into a compact circuit board, reducing system complexity and size while improving integration and reliability. With multiple independent current signal acquisition channels, it can simultaneously acquire current values ​​from multiple channels in real time, providing greater flexibility.

[0058] Although embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A current acquisition board, characterized in that, include: Power conversion module (100), switching module (200), first current detection module (300) and second current detection module (400); The power conversion module (100) is used to convert the power supply voltage and output multiple power supply voltages; The switching module (200) is connected to the power conversion module and is used to turn on the first current detection module (300) or the second current detection module (400) based on the received switching enable signal. The first current detection module (300) is connected to the power conversion module (100), the switching module (200) and the circuit to be collected, and is used to collect the current of the circuit to be collected within a first current amplitude range after being turned on; The second current detection module (400) is connected to the power conversion module (100), the switching module (200), the first current detection module (300) and the circuit to be acquired, and is used to acquire the current of the circuit to be acquired within a second current amplitude range after it is turned on.

2. The current acquisition board according to claim 1, characterized in that, The power conversion module (100) includes: A voltage stabilizing and filtering unit (101) is used to stabilize the power supply and filter out noise, and output a first power supply voltage; The first voltage conversion unit (102) is connected to the voltage stabilizing and filtering unit (101) and is used to convert the first power supply voltage and output the second power supply voltage. The second voltage conversion unit (103) is connected to the first voltage conversion unit (102) and is used to convert the second power supply voltage and output the third power supply voltage.

3. The current acquisition board according to claim 2, characterized in that, The switching module (200) includes: A switching enable signal input unit (201) is connected to the voltage regulation and filtering unit (101) and is used to turn on or off the input of the switching enable signal based on an external detection control signal under the first power supply voltage. The circuit switching unit (202) is connected to the switching enable signal input unit (201) and is used to turn on the first current detection module (300) or the second current detection module (400) based on the switching enable signal. The reference voltage input unit (203) is connected to the first voltage conversion unit (102) and is used to regulate the second power supply voltage to obtain the reference voltage.

4. The current acquisition board according to claim 2, characterized in that, The first current detection module (300) includes: The first current detection unit (301) is connected to the second voltage conversion unit (103), the switching module (200) and the circuit to be acquired, and is used to perform a first current detection on the circuit to be acquired when it is turned on under the third power supply voltage; The first operational amplifier unit (302) is connected to the first current detection unit (301) and the first voltage conversion unit (102) and is used to amplify the analog signal of the first current detection under the second power supply voltage and output the current detection result.

5. The current acquisition board according to claim 4, characterized in that, The second current detection module (400) includes: The second current detection unit (401) is connected to the second voltage conversion unit (103), the first current detection unit (301) and the circuit to be acquired, and is used to perform a second current detection on the circuit to be acquired when it is turned on under the third power supply voltage. The second operational amplifier unit (402) is connected to the second current detection unit (401) and the first voltage conversion unit (102) and is used to amplify the analog signal of the second current detection under the power supply of the second power supply voltage and output the current detection result.

6. The current acquisition board according to claim 2, characterized in that, The voltage stabilizing and filtering unit (101) includes: an input terminal of the power supply, the input terminal of the power supply being connected to the first terminal of the first diode and the first terminal of the second diode, the second terminal of the first diode being connected to the first terminal of the first inductor and the first terminal of the first capacitor, the second terminal of the first inductor being connected to the first terminal of the second capacitor, the first terminal of the third capacitor, the first terminal of the fourth capacitor, the output terminal of the first power supply voltage and the first terminal of the first resistor, the second terminal of the first resistor being connected to the first terminal of the power indicator light, and the second terminal of the second diode, the second terminal of the first capacitor, the second terminal of the second capacitor, the second terminal of the third capacitor, the second terminal of the fourth capacitor and the second terminal of the power indicator light being connected to a ground point; The first voltage conversion unit (102) includes: a power management integrated circuit, the first terminal of which is connected to the output terminal of the first power supply voltage, the second terminal of which is connected to the first terminal of the fifth capacitor, the first terminal of the sixth capacitor, and the output terminal of the second power supply voltage, and the third terminal of which, the second terminal of the fifth capacitor, and the second terminal of the sixth capacitor are connected to the ground point; The second voltage conversion unit (103) includes: a low-dropout regulator, the first terminal of which is connected to the output terminal of the second power supply voltage and the first terminal of the second resistor, the second terminal of which is connected to the second terminal of the second resistor and the first terminal of the seventh capacitor, the third terminal of which is connected to the first terminal of the eighth capacitor, the first terminal of the ninth capacitor and the output terminal of the third power supply voltage, and the second terminal of the seventh capacitor, the second terminal of the eighth capacitor and the second terminal of the ninth capacitor are connected to the grounding point.

7. The current acquisition board according to claim 3, characterized in that, The switching enable signal input unit (201) includes: an optocoupler, wherein the first end of the light-emitting side of the optocoupler is connected to the first end of the external detection control signal, the second end of the light-emitting side is connected to the first end of the third resistor, the second end of the third resistor is connected to the second end of the external detection control signal, the first end of the light-receiving side of the optocoupler is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the output end of the first power supply voltage; The circuit switching unit (202) includes: a relay, the first end of which is connected to the output terminal of the second power supply voltage and the first end of the first switching diode, the second end of which is connected to the first end of the fifth resistor, the second end of the fifth resistor is connected to the second end of the first switching diode and the first end of the second switching diode, the second end of the second switching diode is connected to the first end of the sixth resistor, the second end of the sixth resistor is connected to the second end of the light-receiving side of the optocoupler, the third end of the second switching diode is connected to the ground point, the third end of the relay is connected to the first end of the circuit to be acquired and the first end of the tenth capacitor, and the second end of the tenth capacitor is connected to the ground point; The reference voltage input unit (203) includes: a voltage reference chip, the first end of which is connected to the first end of the seventh resistor and the first end of the eighth resistor, the second end of the seventh resistor is connected to the output terminal of the second power supply voltage, and the second end of the eighth resistor and the second end of the voltage reference chip are connected to the ground point.

8. The current acquisition board according to claim 5, characterized in that, The first current detection unit (301) includes: a first current detection amplifier, the first end of the first current detection amplifier being connected to the third end of the relay of the switching module (200) and the first end of the first sampling resistor, the second end of the first current detection amplifier being connected to the second end of the first sampling resistor and the fourth end of the relay, the third end of the first current detection amplifier being connected to the first end of the eleventh capacitor and the output terminal of the third power supply voltage, the fourth end of the first current detection amplifier being connected to the first end of the ninth resistor, the second end of the ninth resistor being connected to the first end of the twelfth capacitor, the fifth and sixth ends of the first current detection amplifier being connected to the first end of the voltage reference chip of the switching module and the first end of the thirteenth capacitor, and the second ends of the eleventh capacitor, the twelfth capacitor, and the thirteenth capacitor being connected to a ground point; The first operational amplifier unit (302) is a first operational amplifier. The first terminal of the first operational amplifier is connected to the second terminal of the ninth resistor. The second terminal of the first operational amplifier is connected to the first terminal of the tenth resistor and the first terminal of the eleventh resistor. The third terminal of the first operational amplifier is connected to the second terminal of the eleventh resistor and the first terminal of the twelfth resistor. The second terminal of the twelfth resistor is connected to the first terminal of the fourteenth capacitor and the first current detection result output terminal. The second terminal of the tenth resistor and the second terminal of the fourteenth capacitor are connected to the grounding point.

9. The current acquisition board according to claim 8, characterized in that, The second current detection unit (401) includes: a second current detection amplifier, the first terminal of the second current detection amplifier being connected to the first terminal of the second sampling resistor, the second terminal of the second current detection amplifier being connected to the second terminal of the second sampling resistor, the first terminal of the first sampling resistor, the fourth terminal of the relay, the first terminal of the fifteenth capacitor, and the second terminal of the circuit to be sampled, the third terminal of the second current detection amplifier being connected to the first terminal of the sixteenth capacitor and the output terminal of the third power supply voltage, the fourth terminal of the second current detection amplifier being connected to the first terminal of the thirteenth resistor, the second terminal of the thirteenth resistor being connected to the first terminal of the seventeenth capacitor, the fifth and sixth terminals of the second current detection amplifier being connected to the first terminal of the voltage reference chip and the first terminal of the eighteenth capacitor, and the second terminals of the fifteenth capacitor, the sixteenth capacitor, the seventeenth capacitor, and the eighteenth capacitor being connected to the ground point; The second operational amplifier unit (402) includes: a second operational amplifier, the first terminal of the second operational amplifier being connected to the second terminal of the thirteenth resistor, the second terminal of the second operational amplifier being connected to the first terminals of the fourteenth and fifteenth resistors, the third terminal of the second operational amplifier being connected to the second terminal of the fifteenth resistor and the first terminal of the sixteenth resistor, the second terminal of the sixteenth resistor being connected to the first terminal of the nineteenth capacitor and the second current detection result output terminal, the power supply terminal of the second operational amplifier being connected to the output terminal of the second power supply voltage and the first terminal of the twentieth capacitor, and the second terminal of the fourteenth resistor, the second terminal of the nineteenth capacitor, the second terminal of the twentieth capacitor and the ground terminal of the second operational amplifier being connected to the grounding point.

10. A multi-channel current acquisition board, characterized in that, include: The power conversion module (100) includes the same number of switching modules (200), a first current detection module (300), and a second current detection module (400).

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