Internal self-calibration system of digital voltage-stabilized power supply and control method of internal self-calibration system

Abstract

The invention discloses an internal self-calibration system of a digital stabilized power supply and a control method thereof, and the system comprises a stabilized power supply main circuit module which is used for transmitting preset calibration parameters to a high-precision resistor module; the high-precision resistor module is used for receiving the preset calibration parameters, matching calibration data according to the preset calibration parameters and sending the calibration data to the stabilized power supply main circuit module; the voltage-stabilized power supply main circuit module is also used for receiving calibration data, calculating calibration deviation according to the calibration data and calibrating the voltage-stabilized power supply according to the calibration deviation; and the bidirectional communication module is used for providing communication interaction for the high-precision resistor module and the stabilized voltage supply main circuit module so as to perform data interaction. Before an external load is connected, rapid, automatic and high-precision internal self-calibration can be realized so as to ensure that the power supply can provide stable and accurate output from power-on, thereby improving the reliability of the power supply and the user experience.

Description

Technical Field

[0001] The present invention relates to the technical field of power supply calibration, and in particular to an internal self-calibration system of a digital voltage-stabilized power supply and a control method thereof. Background Art

[0002] The output accuracy of digital regulated power supplies is crucial to the operation of electronic equipment, and calibration is a key step in ensuring this accuracy. Early calibration methods relied on external high-precision instruments. While these instruments achieved high accuracy, they were expensive, complex to operate, required specialized personnel, and had high calibration costs. Furthermore, due to aging components, factory calibration accuracy could be difficult to maintain, making frequent external calibration impractical.

[0003] To this end, some digital voltage-stabilized power supplies with internal self-calibration or adaptive adjustment functions have emerged in the prior art. A common solution is to sample the output voltage and current values ​​after connecting an external load, compare them with the internally set target values, and adjust the output in real time by a microcontroller (MCU). However, this solution that relies on the actual external load has many drawbacks: (1) Due to the complex and variable impedance characteristics of the external load, the sampling and adjustment based on this may be inaccurate or produce oscillations, and the accuracy is sensitive to specific load conditions. Therefore, the calibration accuracy is greatly affected by the external load characteristics and has poor universality; (2) At the initial startup of the power supply or when the load is just connected but the calibration is not completed, the output accuracy is not guaranteed, which may cause equipment abnormality or damage. Therefore, the output accuracy cannot be guaranteed before the actual power supply, which poses a risk to sensitive loads; (3) The calibration process may be cumbersome. If it relies on detecting the external load to start, the user may need to perform specific operations. The operation steps for multi-point calibration are complicated and difficult to fully automate; (4) Sampling, calculation and adjustment based on the external load require a certain amount of time, resulting in a significant delay from the startup of the power supply to the stable and accurate output, affecting the response capability and user experience.

[0004] Therefore, the existing solution of relying on external workload for internal self-calibration cannot fundamentally solve the accuracy and convenience problems encountered by digital regulated power supplies in practical applications. Summary of the Invention

[0005] The present invention provides an internal self-calibration system for a digital voltage-stabilized power supply and a control method thereof. The system can achieve rapid, automatic, and high-precision internal self-calibration without relying on an actual external workload or before connecting an external load, thereby ensuring that the power supply can provide stable and accurate output from the moment it is powered on, thereby fundamentally improving the reliability of the power supply and the user experience.

[0006] To achieve the above objectives, an embodiment of the present invention provides an internal self-calibration system for a digital voltage-regulated power supply, comprising: Voltage-stabilized power supply main circuit module, high-precision resistor module and two-way communication module; The voltage-stabilized power supply main circuit module is used to send preset calibration parameters to the high-precision resistor module; The high-precision resistor module is used to receive the preset calibration parameters, match calibration data according to the preset calibration parameters, and send the calibration data to the voltage-regulated power supply main circuit module; The voltage-stabilized power supply main circuit module is further configured to receive the calibration data, calculate a calibration deviation based on the calibration data, and calibrate the voltage-stabilized power supply based on the calibration deviation; The bidirectional communication module is used to provide communication interaction between the high-precision resistor module and the voltage-regulated power supply main circuit module for data interaction.

[0007] As an improvement to the above solution, the high-precision resistor module includes: High-precision fixed resistance calibration load, electronic switching circuit and sampling circuit; The high-precision fixed resistance calibration load is used to provide a stable reference calibration load for the regulated power supply; The electronic conversion switch circuit is used to control the connection state of the high-precision fixed resistance calibration load and the power output circuit; The sampling circuit is used to measure the current and voltage of the high-precision fixed resistance calibration load according to the preset calibration parameters, and obtain calibration data according to the current and voltage.

[0008] As an improvement to the above solution, if the internal self-calibration system further includes a PWM signal control circuit; The voltage-stabilized power supply main circuit module is further configured to generate a control instruction according to the calibration deviation and send the control instruction to the PWM signal control circuit; The PWM signal control circuit is used to receive the control instruction and generate an adjustment PWM signal according to the control instruction to calibrate the regulated power supply.

[0009] As an improvement to the above solution, the sampling circuit includes: Signal acquisition circuit, load control circuit and voltage divider circuit; The signal acquisition circuit includes an analog-to-digital converter, a first resistor, a second resistor, a first capacitor, and a first electrolytic capacitor; The voltage divider circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; The load control circuit includes a first relay, a first diode, a second diode, a second switch tube and a thirteenth resistor; Wherein, pin 1 of the analog-to-digital converter is connected to the first end of the seventh resistor, pins 2 and 6 of the analog-to-digital converter are grounded, pin 3 of the analog-to-digital converter is connected to the first end of the first resistor, and is connected to the voltage-regulated power supply main circuit module through a bus I2C2, pin 4 of the analog-to-digital converter is connected to the first end of the second resistor, and is connected to the voltage-regulated power supply main circuit module through a bus I2C2, pin 5 of the analog-to-digital converter is connected to a 5V power supply, the second end of the first resistor is connected to the 5V power supply, the first end of the first capacitor is connected to the 5V power supply, the second end of the first capacitor is grounded, the first end of the first electrolytic capacitor is connected to the 5V power supply, and the second end of the first electrolytic capacitor is grounded; A first end of the seventh resistor is connected to the first end of the sixth resistor, and a second end of the seventh resistor is grounded; a second end of the sixth resistor is connected to the first end of the fifth resistor, a second end of the fifth resistor is connected to the first ends of the fourth resistor and the eighth resistor, a second end of the fourth resistor is connected to the power red terminal and the third end of the first relay, and a second end of the eighth resistor is grounded; The first end of the first relay is connected to the first ends of the first diode and the second diode, the second end of the first diode is connected to a 12V power supply, the second end of the second diode is connected to the second end of the first relay and the collector of the second switching tube, the emitter of the second switching tube is grounded, the base of the second switching tube is connected to the first end of the thirteenth resistor, and the second end of the thirteenth resistor is connected to the controlled load.

[0010] As an improvement to the above solution, the sampling circuit includes: Signal acquisition filter circuit, signal amplification circuit and ADC acquisition circuit; The signal acquisition and filtering circuit includes a sampling resistor, a seventeenth resistor, a twenty-second resistor, an eighth capacitor, a twelfth capacitor, an eighteenth resistor, and a twenty-third resistor; The signal amplifying circuit includes an operational amplifier, a sixteenth resistor, a first adjustable resistor, a twenty-fourth resistor, a fourth capacitor, a sixth capacitor, a tenth capacitor, and a thirteenth capacitor; The ADC acquisition circuit includes an analog-to-digital converter, a fourteenth resistor, a fifteenth resistor, a fifth capacitor, and a seventh electrolytic capacitor; wherein, one end of the sampling resistor is connected to one end of the twenty-second resistor and to ground, the other end of the sampling resistor is connected to one end of the seventeenth resistor, the other end of the twenty-second resistor is connected to one end of the twenty-third resistor and one end of the twelfth capacitor, the other end of the twelfth capacitor is grounded, the other end of the twenty-third resistor is connected to the second interface of the operational amplifier, one end of the thirteenth capacitor, and one end of the twenty-fourth resistor, the other end of the seventeenth resistor is connected to one end of the eighth capacitor and one end of the eighteenth resistor, the other end of the eighth capacitor is grounded, and the other end of the eighteenth resistor is connected to the sixteenth resistor, one end of the sixth capacitor, and the third interface of the operational amplifier; The first interface and the eighth interface of the operational amplifier are connected to the third end and the first end of the first adjustable resistor respectively, the seventh interface and the fourth interface of the operational amplifier are connected to the positive and negative 5V power supplies respectively, the sixth interface of the operational amplifier is connected to the other ends of the thirteenth capacitor and the twenty-fourth resistor and the first pin of the analog-to-digital converter, one end of the tenth capacitor is connected to the negative 5V power supply and the other end is grounded, one end of the fourth capacitor is connected to the positive 5V power supply and the other end is grounded, the second end of the first adjustable resistor is connected to the positive 5V power supply, and the other ends of the sixteenth resistor and the sixth capacitor are grounded; Pin 2 and pin 6 of the analog-to-digital converter are grounded, pin 3 and pin 4 of the analog-to-digital converter are respectively connected to one end of the fourteenth resistor and the fifteenth resistor, and are connected to the voltage-regulated power supply main circuit module through bus I2C1, pin 5 of the analog-to-digital converter is connected to a 5V power supply, the other ends of the fourteenth resistor and the fifteenth resistor are connected to a 5V power supply, one end of the fifth capacitor and the seventh electrolytic capacitor are connected to the 5V power supply and the other ends are grounded.

[0011] As an improvement to the above solution, the voltage-stabilized power supply main circuit module includes: Power conversion circuit and control circuit; The control circuit includes a controller, a power filter circuit and a pin header interface; The power supply filter circuit includes a seventh capacitor, a ninth capacitor, an eleventh capacitor, a fourteenth capacitor, a nineteenth resistor and a twentieth resistor; The first to fourth interfaces of the pin header are connected to the 14th to 17th pins of the controller respectively; One end of the seventh capacitor is connected to the 48th pin of the controller and the other end is grounded; one end of the ninth capacitor is connected to the 7th pin of the controller and the other end is grounded; one end of the eleventh capacitor is connected to the 9th pin of the controller and the other end is grounded; one end of the fourteenth capacitor is connected to the 24th pin of the controller and the other end is grounded; one end of the nineteenth resistor is connected to the 44th pin of the controller and the other end is grounded; one end of the twentieth resistor is connected to the 3.3V power supply and the other end is connected to the ninth capacitor.

[0012] As an improvement to the above solution, the power conversion circuit includes: Rectification and filtering circuit, step-down voltage stabilization circuit and protection circuit; The rectifier and filter circuit includes an input interface, a first rectifier bridge and a fifth electrolytic capacitor; The step-down voltage stabilization circuit includes a second linear voltage stabilizer, a third linear voltage stabilizer, a second capacitor, a sixth electrolytic capacitor, a third capacitor, a fourth electrolytic capacitor, a ninth resistor, and a tenth resistor; The protection circuit includes a first voltage stabilizing diode, a third resistor, a second electrolytic capacitor and a third electrolytic capacitor; The first interface and the third interface of the input interface are respectively connected to the third end and the second end of the first rectifier bridge, the second interface of the input interface is grounded, the first end of the first rectifier bridge is connected to a 12V power supply, the fourth end of the first rectifier bridge is connected to the third resistor and one end of the second electrolytic capacitor, and one end of the fifth electrolytic capacitor is connected to the 12V power supply and the other end is grounded; A first end of the second linear regulator is connected to ground, a third end of the second linear regulator is connected to a 5V power supply, a second end and a fourth end of the second linear regulator are connected to a 3.3V power supply, one end of the third capacitor and the fourth electrolytic capacitor are connected to the 3.3V power supply and the other end is grounded, one end of the ninth resistor is connected to the 3.3V power supply and the other end is connected to an AC 3.3V power supply, one end of the tenth resistor is connected to the other end of the third capacitor and the AC ground; a first end of the third linear regulator is connected to a 12V power supply, a second end of the third linear regulator is grounded, a third end of the third linear regulator is connected to a 5V power supply, one end of the second capacitor and the sixth electrolytic capacitor are connected to the 5V power supply and the other end is grounded; The other end of the third resistor is connected to a negative 5V power supply, the other end of the second electrolytic capacitor is grounded, and one end of the first voltage regulator diode and the third electrolytic capacitor is connected to a negative 5V power supply and the other end is grounded.

[0013] As an improvement to the above solution, the controller is a single chip microcomputer.

[0014] As an improvement to the above solution, the bidirectional communication module realizes bidirectional communication interaction through the I2C bus.

[0015] To achieve the above objectives, an embodiment of the present invention provides a method for controlling an internal self-calibration system of a digital voltage-regulated power supply, comprising: When receiving the self-calibration trigger instruction, the voltage-regulated power supply main circuit module sends the preset calibration parameters to the high-precision resistor module through the two-way communication module; The high-precision resistor module receives the preset calibration parameters, matches calibration data according to the preset calibration parameters, and sends the calibration data to the voltage-regulated power supply main circuit module through the two-way communication module; The voltage-stabilized power supply main circuit module receives the calibration data, calculates a calibration deviation according to the calibration data, and calibrates the voltage-stabilized power supply according to the calibration deviation.

[0016] Compared with the prior art, the embodiment of the present invention discloses an internal self-calibration system and control method for a digital voltage-stabilized power supply, which includes a voltage-stabilized power supply main circuit module, a high-precision resistor module, and a bidirectional communication module; the voltage-stabilized power supply main circuit module is used to send preset calibration parameters to the high-precision resistor module; the high-precision resistor module is used to receive the preset calibration parameters, match calibration data according to the preset calibration parameters, and send the calibration data to the voltage-stabilized power supply main circuit module; the voltage-stabilized power supply main circuit module is also used to receive the calibration data, calculate the calibration deviation according to the calibration data, and calibrate the voltage-stabilized power supply according to the calibration deviation; the bidirectional communication module is used to provide communication interaction between the high-precision resistor module and the voltage-stabilized power supply main circuit module for data interaction. Without relying on an external actual workload or before connecting an external load, fast, automatic, and high-precision internal self-calibration can be achieved to ensure that the power supply can provide stable and accurate output from the start of power-on, fundamentally improving the reliability of the power supply and user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a schematic structural diagram of an internal self-calibration system of a digital voltage-stabilized power supply provided by an embodiment of the present invention; Figure 2 This is a schematic diagram of a sampling circuit provided by an embodiment of the present invention; Figure 3 is another sampling circuit schematic provided by an embodiment of the present invention; Figure 4 This is a schematic diagram of a control circuit provided by an embodiment of the present invention; Figure 5 This is a schematic diagram of a power conversion circuit provided by an embodiment of the present invention; Figure 6 The present invention provides a flow chart of a method for controlling an internal self-calibration system of a digital voltage-stabilized power supply. DETAILED DESCRIPTION

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0019] It should be noted that the terms "comprises" and "specifically" and any variations thereof in the present invention are intended to cover non-exclusive inclusions. For example, a process, method, system, product or apparatus comprising a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units that are not explicitly listed or are inherent to these processes, methods, products or apparatuses.

[0020] See also Figure 1 , Figure 1 1 is a schematic structural diagram of an internal self-calibration system of a digital voltage-stabilized power supply provided by an embodiment of the present invention, wherein the internal self-calibration system of the digital voltage-stabilized power supply comprises: Voltage-stabilized power supply main circuit module, high-precision resistor module and two-way communication module; The voltage-stabilized power supply main circuit module is used to send preset calibration parameters to the high-precision resistor module; The high-precision resistor module is used to receive the preset calibration parameters, match calibration data according to the preset calibration parameters, and send the calibration data to the voltage-regulated power supply main circuit module; The voltage-stabilized power supply main circuit module is further configured to receive the calibration data, calculate a calibration deviation based on the calibration data, and calibrate the voltage-stabilized power supply based on the calibration deviation; The bidirectional communication module is used to provide communication interaction between the high-precision resistor module and the voltage-regulated power supply main circuit module for data interaction.

[0021] For example, when the power supply of the internal self-calibration system of the digital voltage-stabilized power supply is powered on or a specific trigger condition is met (such as the user manually triggering the calibration instruction), the system first performs a short delay to ensure that the main circuit of the power supply is initially stable. The voltage-stabilized power supply main circuit module serves as the control core and starts to initialize the self-calibration related modules, including the high-precision resistor module (including high-precision resistors, intelligent conversion switches, AD The voltage-regulated power supply main circuit module drives the electronic conversion switch circuit in the high-precision resistor module to close through a control signal (such as an I2C bus instruction or direct control of a relay switch), temporarily connecting the built-in high-precision fixed resistance calibration load to the power supply output circuit; the high-precision fixed resistance calibration load serves as a reference load with a known resistance value, replacing an external uncertain load, and providing a stable electrical environment for calibration; the voltage-regulated power supply main circuit module sends preset calibration parameters (including target voltage and current set points, such as 1V, 5V, and other voltage points that need to be calibrated) to the high-precision resistor module; the high-precision resistor module receives the preset calibration parameters through the two-way communication module with the voltage-regulated power supply main circuit module, and automatically matches internal calibration data (such as the standard current value at the corresponding target voltage) according to the preset calibration parameters to achieve an automatic tracking function; the calibration data is sent to the voltage-regulated power supply main circuit module; the voltage-regulated power supply main circuit module receives the calibration data, calculates a calibration deviation based on the calibration data and an internal preset reference value, and calibrates the voltage-regulated power supply based on the calibration deviation. When the main circuit module of the voltage-regulated power supply determines that the calibration parameters meet the standards, it immediately drives the intelligent electronic transfer switch through a control signal to disconnect, isolating the high-precision resistor module from the power supply output. This prevents the calibration load from interfering with subsequent external load connection or normal power supply output. At the end of the calibration process, the power supply enters normal operating mode, outputting a precisely calibrated voltage or current, ready for direct connection to external loads.

[0022] The embodiment of the present invention integrates a high-precision, fixed calibration load with a known resistance, a controlled electronic switch, a sampling circuit, and a two-way communication module with the main circuit module of the regulated power supply within a digital regulated power supply to construct a system that can be independent of the external actual working load and quickly and automatically perform internal self-calibration at the initial stage of power supply startup or at a specific moment. This solves the problems in the prior art of relying on an external load for calibration, resulting in limited accuracy, poor universality, and an inability to guarantee output accuracy before actual power supply. At the same time, it solves the problems in the prior art of a cumbersome calibration process, the need for external instruments or specific operations, and the delay in power-on output stabilization.

[0023] Specifically, the high-precision resistor module includes: High-precision fixed resistance calibration load, electronic switching circuit and sampling circuit; The high-precision fixed resistance calibration load is used to provide a stable reference calibration load for the regulated power supply; The electronic conversion switch circuit is used to control the connection state of the high-precision fixed resistance calibration load and the power output circuit; The sampling circuit is used to measure the current and voltage of the high-precision fixed resistance calibration load according to the preset calibration parameters, and obtain calibration data according to the current and voltage.

[0024] Exemplarily, the high-precision fixed-resistance calibration load is a built-in, high-precision alloy resistor, which is the core resistor component of the high-precision resistor module. Its resistance is pre-selected based on the power supply output voltage range and serves as a reference calibration load. The electronic conversion switch circuit is integrated within the high-precision resistor module or the voltage-stabilized power supply main circuit module uses a control signal (for example, indirectly controlling the internal switch of the high-precision resistor module through the I2C bus, or directly controlling an external relay / switch to connect or disconnect the calibration resistor from the output circuit) to temporarily connect the high-precision fixed-resistance calibration load in series or in parallel with the power supply output during the calibration phase, and automatically disconnects after the calibration is completed. The sampling circuit is integrated within the high-precision resistor module and is used to accurately measure the current flowing through the high-precision fixed-resistance calibration load (by measuring the voltage across it or using a precision sampling resistor connected in series) and / or the voltage across it when the rated voltage is applied to the high-precision fixed-resistance calibration load.

[0025] Furthermore, if the internal self-calibration system further includes a PWM signal control circuit; The voltage-stabilized power supply main circuit module is further configured to generate a control instruction according to the calibration deviation and send the control instruction to the PWM signal control circuit; The PWM signal control circuit is used to receive the control instruction and generate an adjustment PWM signal according to the control instruction to calibrate the regulated power supply.

[0026] For example, after the calibration load is connected, the MCU in the main circuit module of the voltage-regulated power supply controls the power supply to output a preset calibration voltage (e.g., rated voltage) across a high-precision resistor. The sampling circuit then begins operating, accurately measuring the current flowing through the high-precision resistor (by measuring the voltage across the resistor and calculating its resistance value, or by using a series sampling resistor) and / or the voltage across it, converting the measurement results into analog-to-digital (ADC) values. The sampling circuit then transmits these ADC values ​​to the MCU in real time via bidirectional communication, serving as raw data for calibration adjustments. The MCU compares these ADC values ​​with internally preset reference values ​​(corresponding to theoretical target voltages / currents) to calculate the output deviation (e.g., the difference between the actual voltage and the target voltage). Based on this deviation, the MCU generates an adjusted PWM signal through the PWM signal control circuit, precisely varying the pulse width (duty cycle) and thereby controlling the output of the power supply's main power conversion stage, gradually reducing the deviation between the actual output and the target value. This closed-loop "sampling-feedback-calculation-adjustment" process is repeated until the ADC sampled values ​​converge to within a preset accuracy range (i.e., the deviation between the actual output and the target value is less than the allowable error). Calibration is complete, and the calibration load is disconnected. PWM signal control circuit: The MCU compares and calculates the read AD value with the preset reference value, and accurately calibrates the output voltage / current of the power supply by adjusting the PWM (pulse width modulation) signal (this PWM signal ultimately affects the output of the main power conversion stage of the power supply).

[0027] It's worth noting that if multi-point calibration is required (e.g., calibrating at different voltage / current output points to improve full-range accuracy), the MCU automatically switches to the next target parameter (e.g., switching from 5V to 10V) and repeats the aforementioned self-calibration process: resending the preset calibration parameters to the high-precision resistor module, sampling the AD value under the new parameters, adjusting the PWM until the target is met, and finally completing the full-range calibration. Because the high-precision resistor module has an automatic tracking function, multi-point calibration eliminates the need for manual operation of external loads or frequent parameter settings; the entire process is completed automatically by the MCU and the high-precision resistor module.

[0028] More specifically, the sampling circuit includes: Signal acquisition circuit, load control circuit and voltage divider circuit; The signal acquisition circuit includes an analog-to-digital converter, a first resistor, a second resistor, a first capacitor, and a first electrolytic capacitor; The voltage divider circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; The load control circuit includes a first relay, a first diode, a second diode, a second switch tube and a thirteenth resistor; Wherein, pin 1 of the analog-to-digital converter is connected to the first end of the seventh resistor, pins 2 and 6 of the analog-to-digital converter are grounded, pin 3 of the analog-to-digital converter is connected to the first end of the first resistor, and is connected to the voltage-regulated power supply main circuit module through a bus I2C2, pin 4 of the analog-to-digital converter is connected to the first end of the second resistor, and is connected to the voltage-regulated power supply main circuit module through a bus I2C2, pin 5 of the analog-to-digital converter is connected to a 5V power supply, the second end of the first resistor is connected to the 5V power supply, the first end of the first capacitor is connected to the 5V power supply, the second end of the first capacitor is grounded, the first end of the first electrolytic capacitor is connected to the 5V power supply, and the second end of the first electrolytic capacitor is grounded; A first end of the seventh resistor is connected to the first end of the sixth resistor, and a second end of the seventh resistor is grounded; a second end of the sixth resistor is connected to the first end of the fifth resistor, a second end of the fifth resistor is connected to the first ends of the fourth resistor and the eighth resistor, a second end of the fourth resistor is connected to the power red terminal and the third end of the first relay, and a second end of the eighth resistor is grounded; The first end of the first relay is connected to the first ends of the first diode and the second diode, the second end of the first diode is connected to a 12V power supply, the second end of the second diode is connected to the second end of the first relay and the collector of the second switching tube, the emitter of the second switching tube is grounded, the base of the second switching tube is connected to the first end of the thirteenth resistor, and the second end of the thirteenth resistor is connected to the controlled load.

[0029] like Figure 2 As shown, Figure 2 This is a schematic diagram of a sampling circuit provided by an embodiment of the present invention, wherein the sampling circuit includes: a signal acquisition circuit, a load control circuit, and a voltage divider circuit; Figure 2 In the embodiment, the signal acquisition circuit includes an analog-to-digital converter U1, a first resistor R1, a second resistor R2, a first capacitor C1, and a first electrolytic capacitor E1; the voltage divider circuit includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, and an eighth resistor R8; the load control circuit includes a first relay JK1, a first diode D1, a second diode D2, a second switch tube Q2, and a thirteenth resistor R13; Among them, pin 1 of the analog-to-digital converter U1 is connected to the first end of the seventh resistor R7, pins 2 and 6 of the analog-to-digital converter U1 are grounded, pin 3 of the analog-to-digital converter U1 is connected to the first end of the first resistor R1, and is connected to the voltage-regulated power supply main circuit module through the bus I2C2, pin 4 of the analog-to-digital converter U1 is connected to the first end of the second resistor R2, and is connected to the voltage-regulated power supply main circuit module through the bus I2C2, pin 5 of the analog-to-digital converter U1 is connected to a 5V power supply, the second end of the first resistor R1 is connected to the 5V power supply, the first end of the first capacitor C1 is connected to the 5V power supply, the second end of the first capacitor C1 is grounded, the first end of the first electrolytic capacitor E1 is connected to the 5V power supply, and the second end of the first electrolytic capacitor E1 is grounded; A first end of the seventh resistor R7 is connected to the first end of the sixth resistor R6, and a second end of the seventh resistor R7 is grounded; a second end of the sixth resistor R6 is connected to the first end of the fifth resistor R5, a second end of the fifth resistor R5 is connected to the first ends of the fourth resistor R4 and the eighth resistor R8, a second end of the fourth resistor R4 is connected to the power red terminal and the third end of the first relay JK1, and a second end of the eighth resistor R8 is grounded; A first end of the first relay JK1 is connected to the first end of the first diode D1 and the first end of the second diode D2, the second end of the first diode D1 is connected to a 12V power supply, the second end of the second diode D2 is connected to the second end of the first relay JK1 and to the collector of the second switch tube Q2, the emitter of the second switch tube Q2 is grounded, the base of the second switch tube Q2 is connected to the first end of the thirteenth resistor R13, and the second end of the thirteenth resistor R13 is connected to the controlled load.

[0030] As you can see, the signal acquisition circuit converts the analog voltage signal into a digital value and outputs it via the I2C bus (I2C2_SCL / I2C2_SDA). The first relay in the load control circuit acts as the actuator to control the load's on / off state. When the relay coil is energized, the contacts close, connecting the yellow terminal (P2) of the load to the external load, energizing the load. When the relay coil is de-energized, the contacts open, and the load stops operating. The voltage divider circuit divides the voltage signal input from the red terminal (P1) of the power supply to ensure that the voltage input to the Vin+ pin of the MCP3425 is within its controllable range.

[0031] More specifically, the sampling circuit includes: Signal acquisition filter circuit, signal amplification circuit and ADC acquisition circuit; The signal acquisition and filtering circuit includes a sampling resistor, a seventeenth resistor, a twenty-second resistor, an eighth capacitor, a twelfth capacitor, an eighteenth resistor, and a twenty-third resistor; The signal amplifying circuit includes an operational amplifier, a sixteenth resistor, a first adjustable resistor, a twenty-fourth resistor, a fourth capacitor, a sixth capacitor, a tenth capacitor, and a thirteenth capacitor; The ADC acquisition circuit includes an analog-to-digital converter, a fourteenth resistor, a fifteenth resistor, a fifth capacitor, and a seventh electrolytic capacitor; wherein, one end of the sampling resistor is connected to one end of the twenty-second resistor and to ground, the other end of the sampling resistor is connected to one end of the seventeenth resistor, the other end of the twenty-second resistor is connected to one end of the twenty-third resistor and one end of the twelfth capacitor, the other end of the twelfth capacitor is grounded, the other end of the twenty-third resistor is connected to the second interface of the operational amplifier, one end of the thirteenth capacitor, and one end of the twenty-fourth resistor, the other end of the seventeenth resistor is connected to one end of the eighth capacitor and one end of the eighteenth resistor, the other end of the eighth capacitor is grounded, and the other end of the eighteenth resistor is connected to the sixteenth resistor, one end of the sixth capacitor, and the third interface of the operational amplifier; The first interface and the eighth interface of the operational amplifier are connected to the third end and the first end of the first adjustable resistor respectively, the seventh interface and the fourth interface of the operational amplifier are connected to the positive and negative 5V power supplies respectively, the sixth interface of the operational amplifier is connected to the other ends of the thirteenth capacitor and the twenty-fourth resistor and the first pin of the analog-to-digital converter, one end of the tenth capacitor is connected to the negative 5V power supply and the other end is grounded, one end of the fourth capacitor is connected to the positive 5V power supply and the other end is grounded, the second end of the first adjustable resistor is connected to the positive 5V power supply, and the other ends of the sixteenth resistor and the sixth capacitor are grounded; Pin 2 and pin 6 of the analog-to-digital converter are grounded, pin 3 and pin 4 of the analog-to-digital converter are respectively connected to one end of the fourteenth resistor and the fifteenth resistor, and are connected to the voltage-regulated power supply main circuit module through bus I2C1, pin 5 of the analog-to-digital converter is connected to a 5V power supply, the other ends of the fourteenth resistor and the fifteenth resistor are connected to a 5V power supply, one end of the fifth capacitor and the seventh electrolytic capacitor are connected to the 5V power supply and the other ends are grounded.

[0032] like Figure 3 As shown, Figure 3 This is another schematic diagram of a sampling circuit provided by an embodiment of the present invention, including a signal acquisition filter circuit, a signal amplification circuit, and an ADC acquisition circuit; Figure 3In the embodiment, the signal acquisition and filtering circuit includes a sampling resistor R21, a seventeenth resistor R17, a twenty-second resistor R22, an eighth capacitor C8, a twelfth capacitor C12, an eighteenth resistor R18, and a twenty-third resistor R23; the signal amplification circuit includes an operational amplifier U7, a sixteenth resistor R16, a first adjustable resistor VR1, a twenty-fourth resistor R24, a fourth capacitor C4, a sixth capacitor C6, a tenth capacitor C10, and a thirteenth capacitor C13; the ADC acquisition circuit includes an analog-to-digital converter U6, a fourteenth resistor R14, a fifteenth resistor R15, a fifth capacitor C5, and a seventh electrolytic capacitor E7; Wherein, one end of the sampling resistor R21 is connected to one end of the twenty-second resistor R22 and to ground, the other end of the sampling resistor R21 is connected to one end of the seventeenth resistor R17, the other end of the twenty-second resistor R22 is connected to one end of the twenty-third resistor R23 and one end of the twelfth capacitor C12, the other end of the twelfth capacitor C12 is grounded, the other end of the twenty-third resistor R23 is connected to the second interface of the operational amplifier U7, one end of the thirteenth capacitor C13, and one end of the twenty-fourth resistor R24, the other end of the seventeenth resistor R17 is connected to one end of the eighth capacitor C8 and one end of the eighteenth resistor R18, the other end of the eighth capacitor C8 is grounded, and the other end of the eighteenth resistor R18 is connected to the sixteenth resistor R16, one end of the sixth capacitor C6, and the third interface of the operational amplifier U7; The first interface and the eighth interface of the operational amplifier U7 are respectively connected to the third end and the first end of the first adjustable resistor VR1, the seventh interface and the fourth interface of the operational amplifier U7 are respectively connected to the positive and negative 5V power supplies, the sixth interface of the operational amplifier U7 is connected to the other end of the thirteenth capacitor C13 and the twenty-fourth resistor R24 ​​and the first pin of the analog-to-digital converter U6, one end of the tenth capacitor C10 is connected to the negative 5V power supply and the other end is grounded, one end of the fourth capacitor C4 is connected to the positive 5V power supply and the other end is grounded, the second end of the first adjustable resistor VR1 is connected to the positive 5V power supply, and the other ends of the sixteenth resistor R16 and the sixth capacitor C6 are grounded; Pin 2 and pin 6 of the analog-to-digital converter U6 are grounded, pin 3 and pin 4 of the analog-to-digital converter U6 are respectively connected to one end of the fourteenth resistor R14 and the fifteenth resistor R15, and are connected to the voltage-regulated power supply main circuit module through the bus I2C1, pin 5 of the analog-to-digital converter U6 is connected to a 5V power supply, the other end of the fourteenth resistor R14 and the fifteenth resistor R15 are connected to a 5V power supply, one end of the fifth capacitor C5 and the seventh electrolytic capacitor E7 are connected to the 5V power supply and the other end is grounded.

[0033] As you can understand, the signal acquisition and filtering circuit utilizes sampling resistor R21. When load current flows from P3 (black terminal load) through R21, Ohm's law states that the greater the current, the greater the voltage difference across R21. This voltage difference is detected to indirectly measure the load current. RC filtering is performed on the voltage signal across R21 to remove high-frequency noise (such as load current fluctuations and electromagnetic interference), ensuring a pure signal for the op amp input. The signal amplification circuit amplifies the tiny voltage to a range suitable for ADC acquisition. C4 and C10 are used for filtering to remove power supply noise. AGND is the analog ground, ensuring signal purity. The ADC acquisition circuit converts the amplified voltage signal into a digital voltage signal and outputs it via the I2C bus.

[0034] Specifically, the voltage-stabilized power supply main circuit module includes: Power conversion circuit and control circuit; The control circuit includes a controller, a power filter circuit and a pin header interface; The power supply filter circuit includes a seventh capacitor, a ninth capacitor, an eleventh capacitor, a fourteenth capacitor, a nineteenth resistor and a twentieth resistor; The first to fourth interfaces of the pin header are connected to the 14th to 17th pins of the controller respectively; One end of the seventh capacitor is connected to the 48th pin of the controller and the other end is grounded; one end of the ninth capacitor is connected to the 7th pin of the controller and the other end is grounded; one end of the eleventh capacitor is connected to the 9th pin of the controller and the other end is grounded; one end of the fourteenth capacitor is connected to the 24th pin of the controller and the other end is grounded; one end of the nineteenth resistor is connected to the 44th pin of the controller and the other end is grounded; one end of the twentieth resistor is connected to the 3.3V power supply and the other end is connected to the ninth capacitor.

[0035] like Figure 4 As shown, Figure 4 This is a schematic diagram of a control circuit provided by an embodiment of the present invention. Figure 4The control circuit includes a controller U5, a power filter circuit and a pin header interface J1; the power filter circuit includes a seventh capacitor C7, a ninth capacitor C9, an eleventh capacitor C11, a fourteenth capacitor C14, a nineteenth resistor R19 and a twentieth resistor R20; the controller U5 is an STM32F030C8T6 single-chip microcomputer, which is a microcontroller unit (MCU) in the main circuit module of the voltage-stabilized power supply and is the control core of the entire system. The first pin of the controller U5 is connected to a backup 3.3V battery for maintaining module data such as the RTC (real-time clock) after power failure, and is pulled up to 3.3V through the twentieth resistor R20; the 2nd to 5th pins of the controller U5 are connected to switches K4-K1 respectively; the first ... Pin 7 is the reset pin, which is maintained at a high level through the twentieth resistor R20 (10kΩ pull-up resistor) and connected to the ninth capacitor C9 to suppress interference. When an external trigger (such as a button) or voltage abnormality occurs, NRST is pulled low to reset the microcontroller and restart program execution; pins 8 and 9 of the controller U5 are connected to the 3.3V power supply through the eleventh capacitor C11; pins 14-17 of the controller U5 are respectively connected to the 1st-4th interfaces of the pin header J1; pins 20-21 of the controller U5 are connected to pins 4 and 3 of the analog-to-digital converter U1 through the bus I2C2; pins 23-24 of the controller U5 are connected to the 3.3V power supply through the fourteenth capacitor C14; pin 25 of the controller U5 is connected to the control load FZ CON; pin 33 of the controller U5 is connected to the buzzer BELL_CON; pins 44 and 48 of the controller U5 are connected to the 3.3V power supply through the seventh capacitor C7 and the nineteenth resistor R19; pins 45-46 of the controller U5 are connected to pins 3-4 of the analog-to-digital converter U6 through the bus I2C1.

[0036] Specifically, the power conversion circuit includes: Rectification and filtering circuit, step-down voltage stabilization circuit and protection circuit; The rectifier and filter circuit includes an input interface, a first rectifier bridge and a fifth electrolytic capacitor; The step-down voltage stabilization circuit includes a second linear voltage stabilizer, a third linear voltage stabilizer, a second capacitor, a sixth electrolytic capacitor, a third capacitor, a fourth electrolytic capacitor, a ninth resistor, and a tenth resistor; The protection circuit includes a first voltage stabilizing diode, a third resistor, a second electrolytic capacitor and a third electrolytic capacitor; The first interface and the third interface of the input interface are respectively connected to the third end and the second end of the first rectifier bridge, the second interface of the input interface is grounded, the first end of the first rectifier bridge is connected to a 12V power supply, the fourth end of the first rectifier bridge is connected to the third resistor and one end of the second electrolytic capacitor, and one end of the fifth electrolytic capacitor is connected to the 12V power supply and the other end is grounded; A first end of the second linear regulator is connected to ground, a third end of the second linear regulator is connected to a 5V power supply, a second end and a fourth end of the second linear regulator are connected to a 3.3V power supply, one end of the third capacitor and the fourth electrolytic capacitor are connected to the 3.3V power supply and the other end is grounded, one end of the ninth resistor is connected to the 3.3V power supply and the other end is connected to an AC 3.3V power supply, one end of the tenth resistor is connected to the other end of the third capacitor and the AC ground; a first end of the third linear regulator is connected to a 12V power supply, a second end of the third linear regulator is grounded, a third end of the third linear regulator is connected to a 5V power supply, one end of the second capacitor and the sixth electrolytic capacitor are connected to the 5V power supply and the other end is grounded; The other end of the third resistor is connected to a negative 5V power supply, the other end of the second electrolytic capacitor is grounded, and one end of the first voltage regulator diode and the third electrolytic capacitor is connected to a negative 5V power supply and the other end is grounded.

[0037] like Figure 5 As shown, Figure 5 This is a schematic diagram of a power conversion circuit provided by an embodiment of the present invention, wherein the power conversion circuit includes a rectifier and filter circuit, a step-down and voltage stabilization circuit, and a protection circuit; Figure 5 In the embodiment, the rectifier and filter circuit includes an input interface CON1, a first rectifier bridge DB1 and a fifth electrolytic capacitor E5; the buck stabilization circuit includes a second linear regulator U2, a third linear regulator U3, a second capacitor C2, a sixth electrolytic capacitor E6, a third capacitor C3, a fourth electrolytic capacitor E4, a ninth resistor R9 and a tenth resistor R10; the protection circuit includes a first zener diode Z1, a third resistor R3, a second electrolytic capacitor E2 and a third electrolytic capacitor E3; Among them, the first interface and the third interface of the input interface CON1 are connected to the third end and the second end of the first rectifier bridge DB1 respectively, the second interface of the input interface CON1 is grounded, the first end of the first rectifier bridge DB1 is connected to the 12V power supply, the fourth end of the first rectifier bridge DB1 is connected to the third resistor R3 and one end of the second electrolytic capacitor E2, and one end of the fifth electrolytic capacitor E5 is connected to the 12V power supply and the other end is grounded; A first end of a second linear regulator U2 is connected to ground, a third end of the second linear regulator U2 is connected to a 5V power supply, a second end and a fourth end of the second linear regulator U2 are connected to a 3.3V power supply, one end of a third capacitor C3 and a fourth electrolytic capacitor E4 are connected to the 3.3V power supply and the other end is grounded, one end of a ninth resistor R9 is connected to the 3.3V power supply and the other end is connected to VDDA3.3V power supply, one end of a tenth resistor R10 is connected to the third capacitor C3 and the other end is connected to AC ground; a first end of a third linear regulator U3 is connected to a 12V power supply, a second end of the third linear regulator U3 is grounded, a third end of the third linear regulator U3 is connected to a 5V power supply, one end of the second capacitor C2 and a sixth electrolytic capacitor E6 are connected to the 5V power supply and the other end is grounded; The other end of the third resistor R3 is connected to the negative 5V power supply, the other end of the second electrolytic capacitor E2 is grounded, one end of the first voltage stabilizing diode Z1 and the third electrolytic capacitor E3 is connected to the negative 5V power supply and the other end is grounded.

[0038] As you can understand, the power conversion circuit gradually converts the input voltage into the multiple power levels required by the system (such as +12V, +5V, 3.3V, and VDDA_3.3V). DB1 converts the input AC voltage (or voltage with AC components) into unidirectional pulsating DC (regardless of the input voltage polarity, the output is always a positive voltage to the +12V terminal). E5 filtering smoothes the pulsating DC voltage and reduces voltage fluctuations (large-capacity electrolytic capacitors are suitable for filtering low-frequency ripple). The buck regulator circuit stabilizes the power supply voltage and performs power filtering to prevent digital circuit noise from interfering with analog circuits. The protection circuit utilizes the reverse breakdown characteristics of the Zener diode to stabilize the -5V terminal voltage at 5.1V and stabilize the negative power supply voltage.

[0039] Specifically, the controller is a single chip microcomputer.

[0040] Specifically, the bidirectional communication module realizes bidirectional communication interaction through the I2C bus.

[0041] An embodiment of the present invention discloses an internal self-calibration system for a digital voltage-stabilized power supply, comprising a voltage-stabilized power supply main circuit module, a high-precision resistor module, and a bidirectional communication module; the voltage-stabilized power supply main circuit module is used to send preset calibration parameters to the high-precision resistor module; the high-precision resistor module is used to receive the preset calibration parameters, match calibration data according to the preset calibration parameters, and send the calibration data to the voltage-stabilized power supply main circuit module; the voltage-stabilized power supply main circuit module is also used to receive the calibration data, calculate the calibration deviation according to the calibration data, and calibrate the voltage-stabilized power supply according to the calibration deviation; the bidirectional communication module is used to provide communication interaction between the high-precision resistor module and the voltage-stabilized power supply main circuit module for data interaction. Without relying on an external actual workload or before connecting an external load, fast, automatic, and high-precision internal self-calibration can be achieved to ensure that the power supply can provide stable and accurate output from the start of power-on, thereby fundamentally improving the reliability of the power supply and user experience.

[0042] See also Figure 6 , Figure 6 1 is a flow chart of a method for controlling an internal self-calibration system of a digital voltage-stabilized power supply provided by an embodiment of the present invention. The method for controlling an internal self-calibration system of a digital voltage-stabilized power supply includes: S1, when receiving the self-calibration trigger command, the voltage-regulated power supply main circuit module sends the preset calibration parameters to the high-precision resistor module through the two-way communication module; S2, the high-precision resistor module receives the preset calibration parameters, matches calibration data according to the preset calibration parameters, and sends the calibration data to the voltage-regulated power supply main circuit module through the two-way communication module; S3, the voltage-stabilized power supply main circuit module receives the calibration data, calculates a calibration deviation according to the calibration data, and calibrates the voltage-stabilized power supply according to the calibration deviation.

[0043] The internal self-calibration system control method of a digital voltage-stabilized power supply provided in an embodiment of the present invention can implement all processes of the internal self-calibration system of the digital voltage-stabilized power supply of the above-mentioned embodiment. The functions of each module in the system and the technical effects achieved are respectively the same as the functions and technical effects achieved by the internal self-calibration method of the digital voltage-stabilized power supply of the above-mentioned embodiment, and will not be repeated here.

[0044] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. An internal self-calibration system for a digital voltage-stabilized power supply, characterized in that: include: Voltage-stabilized power supply main circuit module, high-precision resistor module and two-way communication module; The voltage-stabilized power supply main circuit module is used to send preset calibration parameters to the high-precision resistor module; The high-precision resistor module is used to receive the preset calibration parameters, match calibration data according to the preset calibration parameters, and send the calibration data to the voltage-regulated power supply main circuit module; The voltage-stabilized power supply main circuit module is further configured to receive the calibration data, calculate a calibration deviation based on the calibration data, and calibrate the voltage-stabilized power supply based on the calibration deviation; The bidirectional communication module is used to provide communication interaction between the high-precision resistor module and the voltage-regulated power supply main circuit module for data interaction.

2. The internal self-calibration system of the digital voltage-regulated power supply according to claim 1, wherein: The high-precision resistor module comprises: High-precision fixed resistance calibration load, electronic switching circuit and sampling circuit; The high-precision fixed resistance calibration load is used to provide a stable reference calibration load for the regulated power supply; The electronic conversion switch circuit is used to control the connection state of the high-precision fixed resistance calibration load and the power output circuit; The sampling circuit is used to measure the current and voltage of the high-precision fixed resistance calibration load according to the preset calibration parameters, and obtain calibration data according to the current and voltage.

3. The internal self-calibration system of the digital voltage-regulated power supply according to claim 1, wherein: If the internal self-calibration system further includes a PWM signal control circuit; The voltage-stabilized power supply main circuit module is further configured to generate a control instruction according to the calibration deviation and send the control instruction to the PWM signal control circuit; The PWM signal control circuit is used to receive the control instruction and generate an adjustment PWM signal according to the control instruction to calibrate the regulated power supply.

4. The internal self-calibration system of the digital voltage-stabilized power supply according to claim 2, wherein: The sampling circuit comprises: Signal acquisition circuit, load control circuit and voltage divider circuit; The signal acquisition circuit includes an analog-to-digital converter, a first resistor, a second resistor, a first capacitor, and a first electrolytic capacitor; The voltage divider circuit includes a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor and an eighth resistor; The load control circuit includes a first relay, a first diode, a second diode, a second switch tube and a thirteenth resistor; Wherein, pin 1 of the analog-to-digital converter is connected to the first end of the seventh resistor, pins 2 and 6 of the analog-to-digital converter are grounded, pin 3 of the analog-to-digital converter is connected to the first end of the first resistor, and is connected to the voltage-regulated power supply main circuit module through a bus I2C2, pin 4 of the analog-to-digital converter is connected to the first end of the second resistor, and is connected to the voltage-regulated power supply main circuit module through a bus I2C2, pin 5 of the analog-to-digital converter is connected to a 5V power supply, the second end of the first resistor is connected to the 5V power supply, the first end of the first capacitor is connected to the 5V power supply, the second end of the first capacitor is grounded, the first end of the first electrolytic capacitor is connected to the 5V power supply, and the second end of the first electrolytic capacitor is grounded; A first end of the seventh resistor is connected to the first end of the sixth resistor, and a second end of the seventh resistor is grounded; a second end of the sixth resistor is connected to the first end of the fifth resistor, a second end of the fifth resistor is connected to the first ends of the fourth resistor and the eighth resistor, a second end of the fourth resistor is connected to the power red terminal and the third end of the first relay, and a second end of the eighth resistor is grounded; The first end of the first relay is connected to the first ends of the first diode and the second diode, the second end of the first diode is connected to a 12V power supply, the second end of the second diode is connected to the second end of the first relay and the collector of the second switching tube, the emitter of the second switching tube is grounded, the base of the second switching tube is connected to the first end of the thirteenth resistor, and the second end of the thirteenth resistor is connected to the controlled load.

5. The internal self-calibration system of the digital voltage-regulated power supply according to claim 2, wherein: The sampling circuit comprises: Signal acquisition filter circuit, signal amplification circuit and ADC acquisition circuit; The signal acquisition and filtering circuit includes a sampling resistor, a seventeenth resistor, a twenty-second resistor, an eighth capacitor, a twelfth capacitor, an eighteenth resistor, and a twenty-third resistor; The signal amplifying circuit includes an operational amplifier, a sixteenth resistor, a first adjustable resistor, a twenty-fourth resistor, a fourth capacitor, a sixth capacitor, a tenth capacitor, and a thirteenth capacitor; The ADC acquisition circuit includes an analog-to-digital converter, a fourteenth resistor, a fifteenth resistor, a fifth capacitor, and a seventh electrolytic capacitor; wherein, one end of the sampling resistor is connected to one end of the twenty-second resistor and to ground, the other end of the sampling resistor is connected to one end of the seventeenth resistor, the other end of the twenty-second resistor is connected to one end of the twenty-third resistor and one end of the twelfth capacitor, the other end of the twelfth capacitor is grounded, the other end of the twenty-third resistor is connected to the second interface of the operational amplifier, one end of the thirteenth capacitor, and one end of the twenty-fourth resistor, the other end of the seventeenth resistor is connected to one end of the eighth capacitor and one end of the eighteenth resistor, the other end of the eighth capacitor is grounded, and the other end of the eighteenth resistor is connected to the sixteenth resistor, one end of the sixth capacitor, and the third interface of the operational amplifier; The first interface and the eighth interface of the operational amplifier are connected to the third end and the first end of the first adjustable resistor respectively, the seventh interface and the fourth interface of the operational amplifier are connected to the positive and negative 5V power supplies respectively, the sixth interface of the operational amplifier is connected to the other ends of the thirteenth capacitor and the twenty-fourth resistor and the first pin of the analog-to-digital converter, one end of the tenth capacitor is connected to the negative 5V power supply and the other end is grounded, one end of the fourth capacitor is connected to the positive 5V power supply and the other end is grounded, the second end of the first adjustable resistor is connected to the positive 5V power supply, and the other ends of the sixteenth resistor and the sixth capacitor are grounded; Pin 2 and pin 6 of the analog-to-digital converter are grounded, pin 3 and pin 4 of the analog-to-digital converter are respectively connected to one end of the fourteenth resistor and the fifteenth resistor, and are connected to the voltage-regulated power supply main circuit module through bus I2C1, pin 5 of the analog-to-digital converter is connected to a 5V power supply, the other ends of the fourteenth resistor and the fifteenth resistor are connected to a 5V power supply, one end of the fifth capacitor and the seventh electrolytic capacitor are connected to the 5V power supply and the other ends are grounded.

6. The internal self-calibration system of the digital voltage-regulated power supply according to claim 1, wherein: The voltage-stabilized power supply main circuit module includes: Power conversion circuit and control circuit; The control circuit includes a controller, a power filter circuit and a pin header interface; The power supply filter circuit includes a seventh capacitor, a ninth capacitor, an eleventh capacitor, a fourteenth capacitor, a nineteenth resistor and a twentieth resistor; The first to fourth interfaces of the pin header interface are connected to the 14th to 17th pins of the controller respectively; One end of the seventh capacitor is connected to the 48th pin of the controller and the other end is grounded; one end of the ninth capacitor is connected to the 7th pin of the controller and the other end is grounded; one end of the eleventh capacitor is connected to the 9th pin of the controller and the other end is grounded; one end of the fourteenth capacitor is connected to the 24th pin of the controller and the other end is grounded; one end of the nineteenth resistor is connected to the 44th pin of the controller and the other end is grounded; one end of the twentieth resistor is connected to the 3.3V power supply and the other end is connected to the ninth capacitor.

7. The internal self-calibration system of the digital voltage-stabilized power supply according to claim 6, wherein: The power conversion circuit includes: Rectification and filtering circuit, step-down voltage stabilization circuit and protection circuit; The rectifier and filter circuit includes an input interface, a first rectifier bridge and a fifth electrolytic capacitor; The step-down voltage stabilization circuit includes a second linear voltage stabilizer, a third linear voltage stabilizer, a second capacitor, a sixth electrolytic capacitor, a third capacitor, a fourth electrolytic capacitor, a ninth resistor, and a tenth resistor; The protection circuit includes a first voltage stabilizing diode, a third resistor, a second electrolytic capacitor and a third electrolytic capacitor; The first interface and the third interface of the input interface are respectively connected to the third end and the second end of the first rectifier bridge, the second interface of the input interface is grounded, the first end of the first rectifier bridge is connected to a 12V power supply, the fourth end of the first rectifier bridge is connected to the third resistor and one end of the second electrolytic capacitor, and one end of the fifth electrolytic capacitor is connected to the 12V power supply and the other end is grounded; A first end of the second linear regulator is connected to ground, a third end of the second linear regulator is connected to a 5V power supply, a second end and a fourth end of the second linear regulator are connected to a 3.3V power supply, one end of the third capacitor and the fourth electrolytic capacitor are connected to the 3.3V power supply and the other end is grounded, one end of the ninth resistor is connected to the 3.3V power supply and the other end is connected to an AC 3.3V power supply, one end of the tenth resistor is connected to the other end of the third capacitor and the AC ground; a first end of the third linear regulator is connected to a 12V power supply, a second end of the third linear regulator is grounded, a third end of the third linear regulator is connected to a 5V power supply, one end of the second capacitor and the sixth electrolytic capacitor are connected to the 5V power supply and the other end is grounded; The other end of the third resistor is connected to a negative 5V power supply, the other end of the second electrolytic capacitor is grounded, and one end of the first voltage regulator diode and the third electrolytic capacitor is connected to a negative 5V power supply and the other end is grounded.

8. The internal self-calibration system of the digital voltage-regulated power supply according to claim 6, wherein: The controller is a single chip microcomputer.

9. The internal self-calibration system of the digital voltage-regulated power supply according to claim 1, wherein: The bidirectional communication module realizes bidirectional communication interaction through the I2C bus.

10. A method for controlling an internal self-calibration system of a digital voltage-stabilized power supply, characterized in that: include: When receiving the self-calibration trigger instruction, the voltage-regulated power supply main circuit module sends the preset calibration parameters to the high-precision resistor module through the two-way communication module; The high-precision resistor module receives the preset calibration parameters, matches calibration data according to the preset calibration parameters, and sends the calibration data to the voltage-regulated power supply main circuit module through the two-way communication module; The voltage-stabilized power supply main circuit module receives the calibration data, calculates a calibration deviation according to the calibration data, and calibrates the voltage-stabilized power supply according to the calibration deviation.

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