A power supply circuit with current self-detection capability

Abstract

The present invention discloses a power supply circuit with current self-checking capability, including a power supply circuit system with current self-checking capability adopted by the method as a whole, the power supply circuit system with current self-checking capability including a circuit electronic component terminal, a current self-checking module and a data analysis and early warning module, the circuit electronic component terminal is used to obtain voltage and current data and enable terminal data of a water meter board under working state, the current self-checking module is used to calculate the voltage and current values ​​of the system under different power enable states, the data analysis and early warning module is used to compare and analyze and issue early warnings based on the calculated current data and the collected and recorded voltage data, the circuit electronic component terminal is electrically connected to the current self-checking module, the current self-checking module is electrically connected to the data analysis and early warning module, the working current is self-checked regularly, compared with the factory reference value, and warning information is issued in a targeted manner, the present invention has the characteristics of online monitoring of current consumption and cost saving.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply circuit self-detection, in particular to a power supply circuit with current self-detection capability. Background Art

[0002] Today's NB smart water meters and gas meters usually use batteries as the main power source. Whether using dry batteries or disposable batteries, there are strict requirements on the working current. The working current of products that have passed factory inspection meets the design requirements. However, due to the harsh working environment, especially the water meter is often in a humid and flooded environment, if the protection measures are not appropriate, the circuit part is easily corroded by water vapor, which eventually causes the circuit to fail. The first manifestation of this failure is the increase in circuit current consumption due to the presence of water vapor.

[0003] At present, water meters are usually inspected and replaced only after the battery voltage drops significantly or fails completely. The circuit part of the replaced water meter is completely unusable due to severe corrosion. If there are process problems in the protection measures during the production process, a large number of failures will occur after installation, resulting in huge losses. If the working current can be self-checked regularly after the water meter is installed and compared with its factory reference value, targeted warning information can be issued. For products with communication capabilities, when the working current information is submitted when communicating with the service platform, the service platform can obtain the use of the installed product. For products that have failed at the beginning but can still work normally, early warning can be given, and replacement operations can be performed at the appropriate time, which can also prevent batch failures of the product. The products replaced in the early warning stage can be reused to the maximum extent after cleaning, drying, verification and maintenance. Therefore, it is necessary to design a power supply circuit with current self-checking capability to monitor current consumption online and save costs. Summary of the invention

[0004] The object of the present invention is to provide a power supply circuit with current self-detection capability to solve the problems raised in the above background technology.

[0005] In order to solve the above-mentioned technical problems, the present invention provides the following technical solutions: a power supply circuit with current self-detection capability, including a power supply circuit system with current self-detection capability adopted by the method as a whole, the power supply circuit system with current self-detection capability including a circuit electronic component terminal, a current self-detection module and a data analysis and early warning module, the circuit electronic component terminal is used to obtain voltage and current data and enable end data under the working state of the water meter board, the current self-detection module is used to calculate the voltage and current values ​​of the system under different power enable states, the data analysis and early warning module is used to compare and analyze and issue early warnings based on the calculated current data and the collected and recorded voltage data, the circuit electronic component terminal is electrically connected to the current self-detection module, and the current self-detection module is electrically connected to the data analysis and early warning module.

[0006] According to the above technical solution, the circuit electronic component terminal includes a battery voltage detection unit, a power supply voltage enable terminal and an analog-to-digital conversion module, the battery voltage detection unit is used to detect the system working battery voltage through different on-resistances and power switches, the power supply voltage enable terminal is used to detect the enable state of the power supply terminal and the voltage terminal set in the circuit, the analog-to-digital conversion module is used to perform analog-to-digital conversion on the apparent power connected to the micro-control unit to obtain a corresponding voltage value, the battery voltage detection unit is electrically connected to the power supply voltage enable terminal, and the power supply voltage enable terminal is electrically connected to the analog-to-digital conversion module.

[0007] According to the above technical solution, the current self-test module includes an enable control module, a high current operation module, a voltage value conversion acquisition module and a self-test current calculation module, the enable control module is used for controlling the high and low states of the power supply and voltage terminals, the high current operation module is used to operate the high current operation under the normal working state and abnormal working state of the system, the voltage value conversion acquisition module is used to convert and acquire the voltage value through an analog-to-digital converter, the self-test current calculation module is used to calculate the current value of the detection circuit through the acquired voltage value, the enable control module is electrically connected to the high current operation module, and the voltage value conversion acquisition module is electrically connected to the self-test current calculation module;

[0008] The enable control module includes a power enable control module and a voltage enable control module. The power enable control module is used to detect the power enable end of the circuit to control the enable level. The voltage enable control module is used to detect the voltage enable end of the circuit to control the enable level. The power enable control module is electrically connected to the voltage enable control module.

[0009] According to the above technical solution, the data analysis and early warning module includes a data curve chart module, a reference value and historical data module, a comparison and judgment module and an output early warning module. The data curve chart module is used to visualize the calculated current value and the recorded voltage value through a curve chart. The reference value and historical data module is used to set the threshold value under the normal state and abnormal state of the current and call the existing historical data. The comparison and judgment module is used to compare and judge the calculated value with the reference value and historical data. The output early warning module is used to output the judgment result and perform status early warning according to the state. The data curve chart module is electrically connected to the reference value and historical data module, and the comparison and judgment module is electrically connected to the output early warning module;

[0010] The data curve chart module includes a current data submodule and a battery voltage data submodule. The current data submodule is used to display the current value calculated by periodic detection in a curve chart, and the battery voltage data submodule is used to display the voltage value obtained and recorded in a curve chart. The current data submodule is electrically connected to the battery voltage data submodule.

[0011] According to the above technical solution, the current self-test method mainly includes the following steps:

[0012] Step S1: A detection circuit for automatically detecting the voltage and current of the battery terminal of the water and gas meter is built in, the system is powered on and started, and the terminal state is enabled to periodically control the operation;

[0013] Step S2: using a dual voltage detection circuit and a power switch to perform high current operation under normal working and abnormal working conditions of the circuit detection system;

[0014] Step S3: Control the enabling state of the power supply voltage, perform analog-to-digital conversion on the power value connected to the microcontroller unit, and obtain a corresponding voltage value;

[0015] Step S4: Calculate the battery voltage when the system is in working state and the current value when supplying power to the micro-control unit system, integrate the calculated current data and recorded voltage data, and form a water meter board periodic current self-detection measurement curve;

[0016] Step S5: Compare and judge the calculated current value with the factory current reference value and historical experience data, output the judgment result, and issue a current value stage warning.

[0017] According to the above technical solution, in step S2, in the water meter current automatic detection circuit, resistors R3, R4, R5 and conducting transistors Q4 and Q5 form a voltage detection circuit for detecting the battery voltage U VBAT ;

[0018] Another voltage detection circuit is composed of resistors R6, R7, R8 and conducting transistors Q6 and Q7, which is used to detect the system working battery voltage U VSYS , the resistor R2 and the conducting transistors Q2 and Q3 form the power switch of the detection circuit;

[0019] When the power enable is high, the switch is turned on, controlling the on-resistance of transistor Q2 to be within the set range, so that the VSYS and VBAT voltage values ​​U VBAT , U VSYS The maximum limit is equal, when the power enable is low, the switch is closed, and the battery voltage U VBAT The system working battery voltage U is supplied to the system through transistor Q1 and resistor R1 VSYS powered by.

[0020] According to the above technical solution, step S3 further includes the following steps:

[0021] Step S31: When the system is in normal working state, the power switch composed of the resistor R2 and the conducting transistors Q2 and Q3 is turned on to operate the high current action required for the valve and wireless communication;

[0022] Step S32: Set a period to perform self-check on the working current of the water meter board, shut down all high current operations, control the power enable to be low, turn off the power switch, and synchronously control the voltage detection terminal enable state to be high;

[0023] Step S33: Control the two voltage detection circuits in the current self-test state to work synchronously, perform analog-to-digital conversion on the apparent powers Va and Vb connected to the microcontroller unit MCU, and obtain the voltage values ​​U of the apparent powers Va and Vb. Va and U Vb ;

[0024] Step S34: Calculate the battery voltage U according to the acquired data VBAT And the system working battery voltage U VSYS , battery voltage U VBAT The calculation formula is:

[0025]

[0026] In the formula, R4, R5 are the detection battery voltage U VBAT The component resistance, U Va is the voltage value of the apparent power Va obtained by the analog-to-digital converter A / D conversion;

[0027] System working battery voltage U VSYS The calculation formula is:

[0028]

[0029] Where, R7, R8 are the working battery voltage U of the detection system. VSYS The component resistance, U Vb It is the voltage value of the apparent power Vb obtained by the analog-to-digital converter A / D conversion.

[0030] According to the above technical solution, step S4 further includes the following steps:

[0031] Step S41: Calculate the battery voltage and the system working battery voltage when the system is in working state, as well as the current value when supplying power to the micro control unit MCU system;

[0032] Step S42: The current calculation formula flowing through the battery voltage VBAT detection circuit is:

[0033]

[0034] In the formula, R1 is the resistance that supplies power to the system working battery voltage through the transistor and the resistor, U VBAT and U VSYS The battery voltage calculated in step S34 and the system working battery voltage value;

[0035] The current calculation formula flowing through the system working battery voltage VSYS detection circuit is:

[0036]

[0037] In the formula, R6, R7, R8 are resistors in another voltage detection circuit composed of resistors and conducting transistors, U VSYS The system working battery voltage value calculated in step S34;

[0038] The current value calculation formula when supplying power to the microcontroller MCU system is:

[0039] I3=I1-I2

[0040] Where I1 and I2 are the calculated current values ​​flowing through the battery voltage and the system working battery voltage under the system working state;

[0041] Step S43: Integrate the converted voltage value and the calculated current value data, upload the current data via communication, and form a water meter board periodic current self-detection measurement curve.

[0042] According to the above technical solution, step S43 further includes the following steps:

[0043] Step S431: establishing a two-dimensional plane periodic current self-test measurement curve graph with time as the horizontal axis and current value as the vertical axis, and synchronously acquiring and inputting the stored historical data;

[0044] Step S432: obtaining the calculated self-test current curve and historical data curve.

[0045] According to the above technical solution, step S5 further includes the following steps:

[0046] Step S51: setting the failure reminder range of the water and gas meter battery according to historical data, and calling the factory reference value of the water and gas meter;

[0047] Step S52: performing a first comparison and judgment on the calculated current value and the factory reference value, and performing a second comparison and judgment on the self-test current curve and the historical data curve;

[0048] Step S53: The first comparison determines whether the current value exceeds the reference value, and the second comparison determines whether the water and gas meter battery enters the failure warning range, and a real-time warning is issued according to the judgment result.

[0049] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention, by providing a circuit electronic component terminal, a current self-test module and a data analysis and early warning module, uses a dual voltage detection circuit and a power switch to jointly perform high-current operations in normal and abnormal working states of the circuit detection system, and controls the enabling state of the power supply voltage, performs analog-to-digital conversion on the power value connected to the micro-control unit, obtains the corresponding voltage value, calculates the battery voltage flowing through the system in the working state and the current value when power is supplied to the micro-control unit system, integrates the calculated current data and the recorded voltage data, forms a water meter board periodic current self-test measurement curve, synchronously compares and judges the calculated current value with the factory current reference value and historical experience data, outputs the judgment result, and performs a current value stage early warning. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0051] Figure 1 It is a schematic diagram of the system module composition of the present invention;

[0052] Figure 2 It is a principle framework diagram of the current self-test system of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0054] See also Figure 1-2 The present invention provides a technical solution: a power supply circuit with current self-checking capability, including the method as a whole adopting a power supply circuit system with current self-checking capability, the power supply circuit system with current self-checking capability includes a circuit electronic component terminal, a current self-checking module and a data analysis and early warning module, the circuit electronic component terminal is used to obtain the voltage and current data and the enabling terminal data of the water meter board under the working state, the current self-checking module is used to calculate the voltage and current values ​​of the system under different power enabling states, the data analysis and early warning module is used to compare and analyze and warn according to the calculated current data and the collected and recorded voltage data, the circuit electronic component terminal and the power supply circuit system are connected to the power supply circuit, and the power supply circuit system is connected to the power supply circuit. The current self-test module is electrically connected, and the current self-test module is electrically connected to the data analysis and early warning module. When there is water vapor on the circuit board and then it is soaked in water, the leakage current increases first and then the current increases rapidly, causing damage to the device and PCB. The current data change trend is obvious. For NB water meters, the current trend is certain. By comparing the calculated current data and the recorded voltage data with the existing empirical data for reference, that is, when the current of the NB water meter changes from 1mA to 1.5mA, that is, the current value increases by 50% or even 100%, a problem occurs, and a real-time early warning is given based on the trend change of the current data.

[0055] The circuit electronic component terminal includes a battery voltage detection unit, a power supply voltage enable terminal and an analog-to-digital conversion module. The battery voltage detection unit is used to detect the system working battery voltage through different on-resistances and power switches. The power supply voltage enable terminal is used to detect the enable status of the power supply terminal and the voltage terminal set in the circuit. The analog-to-digital conversion module is used to perform analog-to-digital conversion on the apparent power connected to the micro-control unit to obtain a corresponding voltage value. The battery voltage detection unit is electrically connected to the power supply voltage enable terminal, and the power supply voltage enable terminal is electrically connected to the analog-to-digital conversion module.

[0056] The current self-check module includes an enable control module, a high current operation module, a voltage value conversion acquisition module and a self-check current calculation module. The enable control module is used to control the high and low states of the power supply and voltage terminals. The high current operation module is used to operate the high current operation under the normal working state and abnormal working state of the system. The voltage value conversion acquisition module is used to convert and acquire the voltage value through an analog-to-digital converter. The self-check current calculation module is used to calculate the current value of the detection circuit through the acquired voltage value. The enable control module is electrically connected to the high current operation module, and the voltage value conversion acquisition module is electrically connected to the self-check current calculation module.

[0057] The enable control module includes a power enable control module and a voltage enable control module. The power enable control module is used to detect the power enable end of the circuit to control the enable level. The voltage enable control module is used to detect the voltage enable end of the circuit to control the enable level. The power enable control module is electrically connected to the voltage enable control module.

[0058] The data analysis and early warning module includes a data curve chart module, a reference value and historical data module, a comparison and judgment module and an output early warning module. The data curve chart module is used to visualize the calculated current value and the recorded voltage value through a curve chart. The reference value and historical data module is used to set the threshold value under the normal state and abnormal state of the current and call the existing historical data. The comparison and judgment module is used to compare and judge the calculated value with the reference value and historical data. The output early warning module is used to output the judgment result and give a status early warning according to the state. The data curve chart module is electrically connected to the reference value and historical data module, and the comparison and judgment module is electrically connected to the output early warning module;

[0059] The data curve chart module includes a current data submodule and a battery voltage data submodule. The current data submodule is used to display the current value calculated by periodic detection in a curve chart, and the battery voltage data submodule is used to display the voltage value obtained and recorded in a curve chart. The current data submodule is electrically connected to the battery voltage data submodule.

[0060] The current self-test method mainly includes the following steps:

[0061] Step S1: A detection circuit for automatically detecting the voltage and current of the battery terminal of the water and gas meter is built in, the system is powered on and started, and the terminal state is enabled to periodically control the operation;

[0062] Step S2: using a dual voltage detection circuit and a power switch to perform high current operation under normal working and abnormal working conditions of the circuit detection system;

[0063] Step S3: Control the enabling state of the power supply voltage, perform analog-to-digital conversion on the power value connected to the microcontroller unit, and obtain a corresponding voltage value;

[0064] Step S4: Calculate the battery voltage when the system is in working state and the current value when supplying power to the micro-control unit system, integrate the calculated current data and recorded voltage data, and form a water meter board periodic current self-detection measurement curve;

[0065] Step S5: Compare and judge the calculated current value with the factory current reference value and historical experience data, output the judgment result, and issue a current value stage warning. After the water and gas meter is installed, it can perform self-inspection of the working current at regular intervals and compare it with its factory reference value. It can issue targeted warning information. For products with communication capabilities, the working current information is submitted when communicating with the service platform, and the service platform can obtain the usage of the installed product.

[0066] In step S2, in the water meter current automatic detection circuit, resistors R3, R4, R5 and conducting transistors Q4 and Q5 form a voltage detection circuit for detecting the battery voltage U VBAT ;

[0067] Another voltage detection circuit is composed of resistors R6, R7, R8 and conducting transistors Q6 and Q7, which is used to detect the system working battery voltage U VSYS , the resistor R2 and the conducting transistors Q2 and Q3 form the power switch of the detection circuit;

[0068] When the power enable is high, the switch is turned on, controlling the on-resistance of transistor Q2 to be within the set range, so that the VSYS and VBAT voltage values ​​U VBAT , U VSYS The maximum limit is equal, when the power enable is low, the switch is closed, and the battery voltage U VBAT The system working battery voltage U is supplied to the system through transistor Q1 and resistor R1 VSYS Power supply, voltage difference U1=I1*R1, and U1 Q1 , U Q1 It is the PN junction voltage of transistor Q1 (about 0.5V-0.7V), where transistor Q1 ensures that when a large current appears in the system, the system working battery voltage VSYS is only 0.7V less than the battery voltage VBAT at most, which can ensure the normal operation of the microcontroller unit MCU.

[0069] Step S3 further comprises the following steps:

[0070] Step S31: When the system is in normal working state, the power switch composed of the resistor R2 and the conducting transistors Q2 and Q3 is turned on to operate the high current action required for the valve and wireless communication;

[0071] Step S32: Set a period to perform self-check on the working current of the water meter board, shut down all high current operations, control the power enable to be low, turn off the power switch, and synchronously control the voltage detection terminal enable state to be high;

[0072] Step S33: Control the two voltage detection circuits in the current self-test state to work synchronously, perform analog-to-digital conversion on the apparent powers Va and Vb connected to the microcontroller unit MCU, and obtain the voltage values ​​U of the apparent powers Va and Vb. Va and U Vb , apparent power is used to indicate the capacity of the transformer. In addition to active power consumption, electrical equipment usually consumes reactive power, of which reactive power is invalid, but it should also be provided by the power grid. The sum of the two is called apparent power;

[0073] Step S34: Calculate the battery voltage U according to the acquired data VBAT And the system working battery voltage U VSYS , battery voltage U VBAT The calculation formula is:

[0074] ​

[0075] In the formula, R4, R5 are the detection battery voltage U VBAT The component resistance, U Va The voltage value of the apparent power Va obtained by the analog-to-digital converter A / D conversion, the two voltage detection circuits work together, when the resistance value is constant, the larger the voltage value of the apparent power Va connected to the microcontroller unit MCU, the greater the detection battery voltage U VBAT Also bigger;

[0076] System working battery voltage U VSYS The calculation formula is:

[0077]

[0078] Where, R7, R8 are the working battery voltage U of the detection system. VSYS The component resistance, U Vb The voltage value of the apparent power Vb obtained by the analog-to-digital converter A / D conversion, the two voltage detection circuits work together, when the resistance value is constant, the larger the voltage value of the apparent power Vb connected to the microcontroller unit MCU, the greater the detection battery voltage U VSYS Also bigger.

[0079] Step S4 further comprises the following steps:

[0080] Step S41: Calculate the battery voltage and the system working battery voltage when the system is in working state, as well as the current value when supplying power to the micro control unit MCU system;

[0081] Step S42: The current calculation formula flowing through the battery voltage VBAT detection circuit is:

[0082]

[0083] In the formula, R1 is the resistance that supplies power to the system working battery voltage through the transistor and the resistor, U VBAT and U VSYS =The battery voltage calculated in step S34 and the system working battery voltage. When the resistance value R1 of the battery voltage supplying power to the system working battery voltage through the transistor and the resistor is constant, the calculated battery voltage U VBAT And the system working battery voltage U VSYS The greater the voltage difference between the two, the greater the current I1 flowing through the battery voltage;

[0084] The current calculation formula flowing through the system working battery voltage VSYS detection circuit is:

[0085]

[0086] In the formula, R6, R7, R8 are resistors in another voltage detection circuit composed of resistors and conducting transistors, U VSYS The system working battery voltage calculated in step S34 is the system working battery voltage. When the resistance values ​​R6, R7, and R8 in another voltage detection circuit composed of a resistor and a conducting transistor are constant, the calculated system working battery voltage U VSYS The larger it is, the greater the current I2 flowing through the system's operating battery voltage will be;

[0087] The current value calculation formula when supplying power to the microcontroller MCU system is:

[0088] I3=I1-I2

[0089] Where, I1 and I2 are the calculated current values ​​flowing through the battery voltage and the system working battery voltage under the system working state. The greater the current difference between the battery voltage and the system working battery voltage, the greater the current value I3 when supplying power to the microcontroller unit MCU system. In other words, the smaller the current value I3 is;

[0090] Step S43: Integrate the converted voltage value and the calculated current value data, upload the current data via communication, and form a water meter board periodic current self-detection measurement curve.

[0091] Step S43 further includes the following steps:

[0092] Step S431: establishing a two-dimensional plane periodic current self-test measurement curve graph with time as the horizontal axis and current value as the vertical axis, and synchronously acquiring and inputting the stored historical data;

[0093] Step S432: Obtain the calculated self-test current curve and historical data curve. For NB water meters, the current trend is certain. By referring to some empirical data, when the current increases by 50%, that is, from 1mA to 1.5mA, the battery begins to fail, and when the current increases by 100%, it is completely failed. According to the current data of the system working calculated in real time, upload it to the data processing platform for judgment;

[0094] Step S433: Use the battery voltage data recorded each time to perform auxiliary detection of the battery status.

[0095] Step S5 further comprises the following steps:

[0096] Step S51: setting the failure reminder range of the water vapor meter battery according to historical data, calling the factory reference value of the water vapor meter, the circuit board of the water vapor meter gradually changes from water vapor to water, the leakage current increases first, and then the current increases rapidly (avalanche) later, causing damage to electronic components and PCB. The change trend of the current in this process is obvious, but it is difficult to find the critical point, so a battery failure reminder range is set;

[0097] Step S52: performing a first comparison and judgment on the calculated current value and the factory reference value, and performing a second comparison and judgment on the self-test current curve and the historical data curve;

[0098] Step S53: The first comparison determines whether the current value exceeds the reference value, and the second comparison determines whether the water meter battery enters the failure warning range. Real-time warning is given according to the judgment result. If the working current can be self-checked regularly after the water meter is installed and compared with its factory reference value, targeted warning information can be issued. Early warning is given for products that have begun to fail but can still work normally. Replacement operations can be carried out at the appropriate time, which can also prevent batch failures of products. Products replaced in the early warning stage can be reused to the maximum extent through cleaning, drying, inspection, maintenance and other operations.

[0099] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0100] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A current self-detection method with current self-detection capability, characterized in that: The current self-test method mainly comprises the following steps: Step S1: A detection circuit for automatically detecting the voltage and current of the battery terminal of the water and gas meter is built in, the system is powered on and started, and the terminal state is enabled to periodically control the operation; Step S2: using a dual voltage detection circuit and a power switch to perform high current operation under normal working and abnormal working conditions of the circuit detection system; Step S3: Control the enabling state of the power supply voltage, perform analog-to-digital conversion on the power value connected to the microcontroller unit, and obtain a corresponding voltage value; Step S4: Calculate the battery voltage when the system is in working state and the current value when supplying power to the micro-control unit system, integrate the calculated current data and recorded voltage data, and form a water meter board periodic current self-detection measurement curve; Step S5: Compare and judge the calculated current value with the factory current reference value and historical experience data, output the judgment result, and issue a current value stage warning; In step S2, in the water meter current automatic detection circuit, resistors R3, R4, R5 and conducting transistors Q4 and Q5 form a voltage detection circuit for detecting the battery voltage. ; Another voltage detection circuit is composed of resistors R6, R7, R8 and conducting transistors Q6 and Q7, which is used to detect the system working battery voltage. , the resistor R2 and the conducting transistors Q2 and Q3 form the power switch of the detection circuit; When the power enable is high, the switch is turned on, controlling the on-resistance of transistor Q2 to be within the set range, so that the VSYS and VBAT voltage values , The maximum limit is equal, the switch is closed when the power enable is low, and the battery voltage The battery voltage is supplied to the system through transistor Q1 and resistor R1 powered by; The step S3 further comprises the following steps: Step S31: When the system is in normal working state, the power switch composed of the resistor R2 and the conducting transistors Q2 and Q3 is turned on to operate the high current action required for the valve and wireless communication; Step S32: Set a period to perform self-check on the working current of the water meter board, shut down all high current operations, control the power enable to be low, turn off the power switch, and synchronously control the voltage detection terminal enable state to be high; Step S33: Control the two voltage detection circuits in the current self-test state to work synchronously, perform analog-to-digital conversion on the apparent powers Va and Vb connected to the microcontroller unit MCU, and obtain the voltage values ​​of the apparent powers Va and Vb. and ; Step S34: Calculate the battery voltage based on the acquired data and system operating battery voltage , battery voltage The calculation formula is: ； In the formula, R4 and R5 are the voltage detection of the battery. The component resistance, is the voltage value of the apparent power Va obtained by the analog-to-digital converter A / D conversion; System operating battery voltage The calculation formula is: ； In the formula, R7 and R8 are the working battery voltage of the detection system. The component resistance, It is the voltage value of the apparent power Vb obtained by the analog-to-digital converter A / D conversion.

2. A current self-detection method with current self-detection capability according to claim 1, characterized in that: The step S4 further comprises the following steps: Step S41: Calculate the battery voltage and the system working battery voltage when the system is in working state, as well as the current value when supplying power to the micro control unit MCU system; Step S42: The current calculation formula flowing through the battery voltage VBAT detection circuit is: ； In the formula, The battery voltage supplies power to the system working battery voltage through the transistor and the resistor. and The battery voltage calculated in step S34 and the system working battery voltage value; The current calculation formula flowing through the system working battery voltage VSYS detection circuit is: ； In the formula, R6, R7, and R8 are resistors in another voltage detection circuit composed of resistors and conducting transistors. The system working battery voltage value calculated in step S34; The current value calculation formula when supplying power to the microcontroller MCU system is: ； In the formula, The calculated current value flowing through the battery voltage and the system working battery voltage under the system working state; Step S43: Integrate the converted voltage value and the calculated current value data, upload the current data via communication, and form a water meter board periodic current self-detection measurement curve.

3. A current self-detection method with current self-detection capability according to claim 2, characterized in that: The step S43 further comprises the following steps: Step S431: establishing a two-dimensional plane periodic current self-test measurement curve graph with time as the horizontal axis and current value as the vertical axis, and synchronously acquiring and inputting the stored historical data; Step S432: obtaining the calculated self-test current curve and historical data curve; Step S433: Use the battery voltage data recorded each time to perform auxiliary detection of the battery status.

4. A current self-detection method with current self-detection capability according to claim 3, characterized in that: The step S5 further comprises the following steps: Step S51: setting the failure reminder range of the water and gas meter battery according to historical data, and calling the factory reference value of the water and gas meter; Step S52: performing a first comparison and judgment on the calculated current value and the factory reference value, and performing a second comparison and judgment on the self-test current curve and the historical data curve; Step S53: The first comparison determines whether the current value exceeds the reference value, and the second comparison determines whether the water and gas meter battery enters the failure warning range, and a real-time warning is issued according to the judgment result.

5. A power supply circuit for a current self-detection method according to any one of claims 1 to 4, characterized in that: The method adopts a power circuit system with current self-checking capability as a whole. The power circuit system with current self-checking capability includes a circuit electronic component terminal, a current self-checking module and a data analysis and early warning module. The circuit electronic component terminal is used to obtain voltage and current data and enable terminal data under the working state of the water meter board. The current self-checking module is used to calculate the voltage and current values ​​of the system under different power enable states. The data analysis and early warning module is used to compare and analyze and warn according to the calculated current data and the collected and recorded voltage data. The circuit electronic component terminal is electrically connected to the current self-checking module, and the current self-checking module is electrically connected to the data analysis and early warning module. When the circuit board is gradually soaked in water from moisture to water, the leakage current increases first and then the current increases rapidly, causing damage to the device and PCB, and the current data has an obvious trend of change. For NB water meters, the current trend is certain. By comparing the calculated current data and the recorded voltage data with the existing empirical data for reference, that is, when the current of the NB water meter changes from 1mA to 1.5mA, that is, the current value increases by 50% or even 100%, a problem occurs, and a real-time early warning is performed according to the trend change of the current data.

6. The power supply circuit of the current self-detection method according to claim 5, characterized in that: The circuit electronic component terminal includes a battery voltage detection unit, a power supply voltage enable terminal and an analog-to-digital conversion module. The battery voltage detection unit is used to detect the system working battery voltage through different on-resistances and power switches. The power supply voltage enable terminal is used to detect the enable status of the power supply terminal and the voltage terminal set in the circuit. The analog-to-digital conversion module is used to perform analog-to-digital conversion on the apparent power connected to the micro-control unit to obtain a corresponding voltage value. The battery voltage detection unit is electrically connected to the power supply voltage enable terminal, and the power supply voltage enable terminal is electrically connected to the analog-to-digital conversion module.

7. The power supply circuit of the current self-detection method according to claim 6, characterized in that: The current self-check module includes an enable control module, a high current operation module, a voltage value conversion acquisition module and a self-check current calculation module, wherein the enable control module is used for controlling the high and low states of the power supply and voltage terminals, the high current operation module is used for operating the high current operation under the normal working state and the abnormal working state of the system, the voltage value conversion acquisition module is used for converting and acquiring the voltage value through an analog-to-digital converter, the self-check current calculation module is used for calculating the current value of the detection circuit through the acquired voltage value, the enable control module is electrically connected to the high current operation module, and the voltage value conversion acquisition module is electrically connected to the self-check current calculation module; The enable control module includes a power enable control module and a voltage enable control module. The power enable control module is used to detect the power enable end of the circuit to control the enable level. The voltage enable control module is used to detect the voltage enable end of the circuit to control the enable level. The power enable control module is electrically connected to the voltage enable control module.

8. The power supply circuit of the current self-detection method according to claim 7, characterized in that: The data analysis and early warning module includes a data curve chart module, a reference value and historical data module, a comparison and judgment module and an output early warning module. The data curve chart module is used to visualize the calculated current value and the recorded voltage value through a curve chart. The reference value and historical data module is used to set the threshold value under the normal state and abnormal state of the current and call the existing historical data. The comparison and judgment module is used to compare and judge the calculated value with the reference value and historical data. The output early warning module is used to output the judgment result and give a status early warning according to the state. The data curve chart module is electrically connected to the reference value and historical data module, and the comparison and judgment module is electrically connected to the output early warning module; The data curve chart module includes a current data submodule and a battery voltage data submodule. The current data submodule is used to display the current value calculated by periodic detection in a curve chart, and the battery voltage data submodule is used to display the voltage value obtained and recorded in a curve chart. The current data submodule is electrically connected to the battery voltage data submodule.

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