A system and method for constant voltage dimmable LED power supply current calibration

Abstract

The application discloses a kind of constant voltage adjustable light LED power supply current calibration system and method, system includes the calibration tool, measured power supply, electronic load and host computer sequentially connected in head and tail;Method includes: S1, start calibration;S2, current adjustment;S3 parameter save.The application is on a common single-chip microcomputer, realizes power supply current calibration by a 0-10V analog interface, solves the selection problem of single-chip microcomputer;Lower cost single-chip microcomputer can be introduced into adjustable light power supply, to reduce hardware material cost.Through an automatic, closed-loop calibration process, the calibration error problem caused by personnel intervention is solved;Automatic calibration scheme can save labor cost, time cost, and avoid the occurrence of human error.

Description

Technical Field

[0001] This invention relates to the fields of intelligent lighting, intelligent power supply, and LED power supply technology, and specifically to a system and method for calibrating the current of a constant voltage adjustable LED power supply. Background Technology

[0002] LEDs have two control modes: constant current and constant voltage. A constant voltage power supply, also called a regulated power supply, requires a fixed output voltage that does not change with external operating conditions such as load or input voltage.

[0003] LEDs have various dimming methods, such as analog dimming and PWM dimming. To control the brightness of an LED, a constant current driver needs to be added between the constant voltage power supply and the LED. The output current of the constant current driver is adjusted by an external adjustable signal (such as 0-10V or PWM), thereby controlling the brightness of the LED.

[0004] Due to differences in hardware characteristics, power supplies require maximum output current calibration after manufacturing to ensure they meet the specifications of power supplies of the same model. Calibration ensures consistent current output, achieving uniform luminous efficacy.

[0005] There are generally two methods for calibrating current:

[0006] One approach is to program the power supply wirelessly, such as using NFC tags, and rewrite the internal parameters of the power supply via external short-range communication. However, wireless methods increase costs, and most LED power supplies currently use metal materials to solve heat dissipation problems, which have a strong shielding effect on wireless signals, making them unsuitable for structural implementation.

[0007] Another method is to program the power supply via a digital interface. This typically involves using a multiplexed dimming interface (0-10V PWM). While this doesn't add a new interface, it alters the power supply's structural design, affecting its waterproofing and dustproofing. This method requires the power supply's dimming interface to support digital communication multiplexing, meaning the microcontroller's I / O must simultaneously support ADC (Analog-to-Digital Conversion) and UART communication. This is currently the mainstream power supply calibration method. Therefore, this method also limits the choice of microcontroller for the power supply. For microcontrollers whose dimming interfaces lack digital communication multiplexing capabilities, the second method cannot be used to calibrate the current. Summary of the Invention

[0008] This invention provides a system and method for calibrating the current of a constant voltage dimmable LED power supply, which effectively solves the technical problem in the prior art that ordinary microcontrollers cannot use a 0-10V input interface to automatically calibrate dimmable power supplies.

[0009] The term "ordinary microcontroller" as used in this article refers to microcontrollers without digital communication multiplexing functionality.

[0010] To achieve the above objectives, the present invention employs the following technical solution:

[0011] The first aspect of this invention discloses a system for calibrating the current of a constant-voltage adjustable-brightness LED power supply. This system includes a calibration fixture, a power supply under test, an electronic load, and a host computer connected sequentially to form a complete closed loop for automated calibration of the constant-voltage adjustable-brightness LED power supply.

[0012] The host computer is used to initiate calibration commands to the calibration fixture;

[0013] The calibration fixture is used to convert digital instructions from the host computer into analog signals and output them to the power supply under test at a frequency agreed upon with the power supply under test.

[0014] The power supply under test is used to convert the analog signal sequence received from the calibration fixture into a digital signal, and perform corresponding operations according to the content of the digital signal;

[0015] The electronic load is used to receive the output current of the power supply under test and send its own current value to the host computer for decision-making.

[0016] Furthermore, the host computer is also used to: set a target current, and initiate a calibration command to the calibration fixture according to the target current; or, in response to the current reading of the electronic load, formulate an adjustment strategy for the calibration current based on the difference between the target current and the current reading of the electronic load, and initiate a calibration command to the calibration fixture according to the adjustment strategy; and collect the current value of the electronic load at a fixed period and compare it with the target current.

[0017] The adjustment strategy includes the adjustment direction and adjustment step of the calibration current.

[0018] In current calibration, the power supply under test (UTP) refers to the circuit or device that requires current measurement, while the calibration fixture is an instrument used to simulate the current signal required by the circuit or device. Typically, the current output of the UTP is presented as an analog signal, and the calibration fixture can convert digital commands into analog signals to calibrate the current of the UTP.

[0019] In this configuration, the calibration fixture converts digital commands into analog signals that match the frequency specified by the power supply under test, enabling precise current measurement and calibration. This ensures that the output current value of the power supply under test matches the expected value, thereby guaranteeing the correctness and reliability of the circuit or equipment.

[0020] Furthermore, the power supply under test includes a 0-10V dimming interface and a direct-connect output interface. The dimming interface is connected to the calibration fixture and is used to receive analog signals; the direct-connect output interface is connected to the electronic load and is used to output current.

[0021] Therefore, the host computer is connected to the calibration fixture to receive calibration fixture commands, the 0-10V dimming interface of the power supply under test is connected to the calibration fixture to receive analog signals from the calibration fixture, the direct output interface is connected to the electronic load to output current, and the electronic load is connected to the host computer to receive the current from the electronic load, thus forming a closed loop between the host computer, the calibration fixture, the power supply under test, and the electronic load.

[0022] Compared to the basic process of current calibration using a conventional microcontroller and calibration fixture, the constant voltage dimmable LED power supply current calibration system employs host computer control. The host computer can initiate calibration commands and set target currents through a software interface, enabling more flexible and convenient operation. In the basic process of current calibration using a conventional microcontroller and calibration fixture, the output value of the calibration fixture needs to be manually adjusted.

[0023] An electronic load is used in this system. The electronic load receives the output current of the power supply under test and sends its own current value to the host computer, thus enabling real-time monitoring and feedback of the power supply's output current. In the basic process of current calibration using a common microcontroller combined with calibration fixtures, manually reading the voltage value of the analog input port and the analog voltage output value of the calibration fixture is required, which is quite cumbersome.

[0024] This system utilizes digital-to-analog signal conversion. The power supply under test converts the analog signal sequence into a digital signal and performs corresponding operations. The calibration program in the microcontroller then calculates the actual value of the power supply current by reading the voltage value at the analog input port and the analog voltage output value from the calibration fixture. In contrast, the basic process of current calibration using a common microcontroller combined with a calibration fixture involves analog signals and is relatively simple.

[0025] In summary, constant voltage dimmable LED power supply current calibration systems offer higher automation and real-time performance, but correspondingly require higher hardware and software costs. In contrast, using a standard microcontroller combined with calibration fixtures to achieve current calibration is relatively simple and suitable for simple circuits and small-scale production.

[0026] Based on the current calibration system of this application, a method for calibrating the current of a constant voltage tunable LED power supply is disclosed in a second aspect of this application, comprising the following steps:

[0027] S1. Start calibration; Set the target current on the host computer and initiate a calibration command to the calibration fixture according to the target current;

[0028] S2. Enter calibration mode; After receiving the calibration command, the calibration fixture converts the digital command received from the host computer into an analog signal and outputs it to the power supply under test; The power supply under test converts the analog signal sequence received from the calibration fixture into a digital signal, and enters calibration mode after the digital signal meets the preset sequence requirements.

[0029] S3. Determination of current adjustment strategy; The host computer acquires the current value of the electronic load at a preset period, responds to the difference between the target current and the current value of the electronic load, determines the adjustment strategy of the calibration current, and sends the calibration command of the adjustment strategy to the calibration fixture.

[0030] S3. Current adjustment: In response to the calibration fixture receiving the calibration command of the adjustment strategy, a preset voltage sequence is output to the dimming interface of the power supply under test; the power supply under test receives the preset voltage sequence and analyzes it, and adjusts the output current accordingly so that the electronic load is adjusted towards the target current.

[0031] In some embodiments, step S2 further includes,

[0032] After receiving the calibration command, the calibration fixture outputs a predetermined voltage sequence of 0-10V to the dimming interface of the power supply under test at preset time intervals.

[0033] Upon confirmation that the agreed-upon voltage meets the preset voltage sequence requirements, the system enters calibration mode. The preset voltage sequence is a specific sequence of 9V, 5V, 2V, 7V, and 10V. Specifically, the power supply samples the 0-10V input voltage at a fixed frequency (once every 100ms). When five consecutive sampled values ​​are 9V, 5V, 2V, 7V, and 10V respectively, the sequence requirement is considered met.

[0034] In calibration mode, the power supply under test only accepts voltage sequence commands and does not respond to dimming signals.

[0035] In this embodiment, in step S2, the power supply under test converts the analog signal into an ADC digital signal in real time and saves it to five built-in storage units using a shift algorithm. The five built-in storage units compare whether the sequence requirements of 9V, 5V, 2V, 7V, and 10V are met within a fixed accuracy range.

[0036] As a preferred embodiment of the above scheme, in step S2, the accuracy range of the storage cell is fixed at ±0.2V.

[0037] As a preferred embodiment of the above scheme, in step S2, the host computer reads the current value of the electronic load at a fixed period of 2 seconds.

[0038] In some embodiments, step S4 further includes, based on the adjustment strategy received by the calibration fixture, parsing the corresponding voltage sequence through instructions, and outputting it to the power supply under test through a 0-10V output interface; the power supply under test receives different voltage sequences and parses them, and adjusts the output current accordingly, including 1) reducing the duty cycle by 1%; 2) reducing the duty cycle by 0.1%; 3) increasing the duty cycle by 1%; 4) increasing the duty cycle by 0.1%.

[0039] In some embodiments, the method further includes,

[0040] The process of step S3 to step S4 is repeated until the target current equals the read current, then the parameter saving process is started.

[0041] The parameter saving process includes:

[0042] When the target current in the calibration process is equal to the current value of the electronic load, parameter saving is started. The current duty cycle of the PWM is recorded as the maximum current output value and saved to the built-in flash.

[0043] Alternatively, the calibration process can be exited, and the power supply under test will, for subsequent 0-10V input signals, be mapped to the output from 0 to the recorded maximum PWM duty cycle value.

[0044] The calibration process aims to match the current value of the electronic load with the desired target current value. Once the match is successful, the calibration process proceeds to the parameter saving stage. During this stage, the current PWM duty cycle is recorded for use in subsequent current output control.

[0045] The reason for recording the current PWM duty cycle as the maximum current output value is to ensure that the electronic load can output the maximum current in subsequent current outputs. Since the PWM duty cycle is directly related to the current output, recording the maximum PWM duty cycle ensures the maximum current output. This improves the accuracy and reliability of the electronic load.

[0046] In some embodiments, in step S2, after the calibration system enters the calibration mode in response to the calibration, the power supply under test will start from a fixed PWM duty cycle.

[0047] In some embodiments, in step S3, the difference between the target current and the current value of the electronic load is used to formulate an adjustment strategy for the calibration current, including:

[0048] 1) If the target current is much greater than the current current, send adjdec10 to the calibration fixture; 2) If the target current is greater than the current current, send adjdec1 to the calibration fixture; 3) If the target current is much less than the current current, send adjinc10 to the calibration fixture; 4) If the target current is less than the current current, send adjinc1 to the calibration fixture; 5) If the target current is equal to the current current, start the parameter saving process.

[0049] Among them, the absolute value of the difference between the index and the index is greater than 0.1A, and the absolute value of the difference between the index and the index is between 0 and 0.1A.

[0050] As a preferred embodiment of the above scheme, in step S3, 1) upon receiving the adjdec10 command, the calibration fixture outputs a specific voltage sequence of 2V, 7V, 2V, 7V, and 10V to the dimming interface of the power supply under test at 100ms intervals; 2) upon receiving the adjdec1 command, the calibration fixture outputs a specific voltage sequence of 7V, 2V, 7V, 2V, and 10V to the dimming interface of the power supply under test at 100ms intervals; 3) upon receiving the adjinc10 command, the calibration fixture outputs a specific voltage sequence of 6V, 3V, 6V, 3V, and 10V to the dimming interface of the power supply under test at 100ms intervals; 4) upon receiving the adjinc1 command, the calibration fixture outputs a specific voltage sequence of 3V, 6V, 3V, 6V, and 10V to the dimming interface of the power supply under test at 100ms intervals.

[0051] The beneficial effects of this invention due to the calibration system and the calibration method based on that system are as follows:

[0052] 1. Power supply current calibration is achieved on a regular microcontroller through a 0-10V analog interface, solving the microcontroller selection problem; lower-cost microcontrollers can be introduced into dimmable power supplies, reducing hardware material costs.

[0053] 2. An automated, closed-loop calibration process solves the calibration error problem that may be caused by human intervention; the automated calibration solution can save labor costs, time costs, and avoid the occurrence of human error. Attached Figure Description

[0054] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below.

[0055] Figure 1 This diagram shows a schematic block diagram of a system for calibrating the current of a constant voltage adjustable LED power supply according to an embodiment of the present disclosure.

[0056] Figure 2This diagram shows a flowchart of the calibration initiation process in a constant voltage dimmable LED power supply current calibration method provided in an embodiment of this disclosure;

[0057] Figure 3 This embodiment of the present disclosure shows the change in the PWM duty cycle of the LED power supply under test after entering calibration mode;

[0058] Figure 4 This diagram illustrates a flowchart of the current adjustment process in a method for calibrating the current of a constant voltage dimmable LED power supply according to an embodiment of this disclosure.

[0059] Figure 5 The flowchart illustrates the parameter saving process in a method for calibrating the current of a constant voltage dimmable LED power supply according to an embodiment of this disclosure. Detailed Implementation

[0060] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0061] like Figure 1 As shown, this embodiment provides a system for calibrating the current of a constant voltage adjustable LED power supply. It includes a calibration fixture, a power supply under test, an electronic load, and a PC connected sequentially to form a complete closed loop for automated calibration of the constant voltage adjustable LED power supply.

[0062] The PC host computer is used to set the target current and initiate calibration commands to the calibration fixture; it collects the current reading of the electronic load, and determines the adjustment direction and adjustment step of the calibration current based on the difference between the current reading of the electronic load and the target current value; and it starts saving parameters after collecting a current that is the same as the preset current.

[0063] The calibration fixture is used to convert digital instructions from the PC host computer into analog signals and output them to the power supply under test at a frequency agreed upon with the power supply under test.

[0064] The power supply under test is used to convert the analog signal sequence received from the calibration fixture into a digital signal and to parse the digital signal; and to perform different operations according to the content of the digital signal.

[0065] The electronic load is used as the output receiver of the power supply under test in constant voltage mode; and sends its own current value to the PC host computer for decision-making via serial port.

[0066] Furthermore, the power supply under test includes a 0-10 dimming interface, which is connected to the calibration fixture for receiving analog signals; the analog interface is connected to the electronic load for outputting current.

[0067] This embodiment also provides a method for calibrating the power supply current of a constant voltage dimmable LED, including the following steps:

[0068] S1. Start calibration, such as Figure 2 As shown; the PC host computer sends the start calibration command adjstart1 to the calibration fixture via the UART interface;

[0069] S2. Enter calibration mode; After receiving the instruction, the calibration fixture outputs a specific voltage sequence (such as 9V, 5V, 2V, 7V, 10V) from 0 to 10V to the dimming interface of the power supply under test at certain time intervals (such as 100ms). The voltage sequence and the acquisition frequency are the agreed sequence and frequency between the power supply under test and the fixture.

[0070] The power supply under test converts the analog signal into an ADC digital signal in real time and saves it to five built-in temporary storage units through a shift algorithm.

[0071] The power supply under test (PST) uses five built-in temporary storage units to compare its performance within a fixed accuracy range (e.g., ±0.2V) against five specific voltage sequences (9V, 5V, 2V, 7V, 10V). If the requirements are met, it enters calibration mode. In this mode, the PST only accepts voltage sequence commands and does not respond to dimming signals. After entering calibration mode, the PST will start with a fixed PWM duty cycle, such as 85% (this is an empirical value to improve calibration efficiency; for most power supplies, it is a PWM output that is close to the target current and can be adjusted according to the actual situation). Figure 3 As shown.

[0072] S3. Determination of current adjustment strategy, such as Figure 4 As shown:

[0073] The host computer reads the current value of the electronic load at a fixed cycle (2 seconds);

[0074] By determining the difference between the current value of the currently acquired electronic load and the target current, the dimming direction and dimming step are determined.

[0075] 1) If the target current is much greater than the current value of the electronic load (the absolute value of the difference is greater than 0.1A), then send adjdec10 to the calibration fixture;

[0076] 2) If the target current is greater than the current value of the electronic load (the absolute value of the difference is between 0 and 0.1A), then send adjdec1 to the calibration fixture;

[0077] 3) If the target current is much smaller than the current value of the electronic load (the absolute value of the difference is greater than 0.1A), then send adjinc10 to the calibration fixture;

[0078] 4) If the target current is less than the current value of the electronic load (the absolute value of the difference is between 0 and 0.1A), then send adjinc1 to the calibration fixture;

[0079] 5) If the target current is equal to the current value of the electronic load, start the parameter saving process.

[0080] S4. Current adjustment: In response to the calibration fixture receiving the calibration command of the adjustment strategy, a preset voltage sequence is output to the analog interface of the power supply under test; the power supply under test receives the preset voltage sequence and analyzes it, and adjusts the output current accordingly so that the electronic load is adjusted towards the target current.

[0081] When the calibration fixture receives instructions under different strategies in step S3, it generates different voltage sequences through instruction parsing and outputs them through the 0-10V output interface;

[0082] 1) Upon receiving the adjdec10 command, the calibration fixture outputs a specific voltage sequence of 2V, 7V, 2V, 7V, and 10V to the dimming interface of the LED power supply at 100ms intervals.

[0083] 2) Upon receiving the adjdec1 command, the calibration fixture outputs a specific voltage sequence of 7V, 2V, 7V, 2V, and 10V to the dimming interface of the LED power supply at 100ms intervals.

[0084] 3) Upon receiving the adjinc10 command, the calibration fixture outputs a specific voltage sequence of 6V, 3V, 6V, 3V, and 10V to the dimming interface of the LED power supply at 100ms intervals.

[0085] 4) Upon receiving the adjinc1 command, the calibration fixture outputs a specific voltage sequence of 3V, 6V, 3V, 6V, and 10V to the dimming interface of the LED power supply at 100ms intervals.

[0086] S41. The power supply under test receives and analyzes different voltage sequences, and adjusts the output current accordingly; including:

[0087] 1) Reduce the duty cycle by 1%;

[0088] 2) Reduce the duty cycle by 0.1%;

[0089] 3) Increase the duty cycle by 1%;

[0090] 4) Increase the duty cycle by 0.1%.

[0091] S42. When the power supply under test outputs different currents, the corresponding electronic load will adjust towards the target current.

[0092] S43. Repeat steps S21 to S25 until the target current equals the read current, then start the parameter saving process.

[0093] In this embodiment, the parameter saving process is as follows: Figure 5 As shown.

[0094] When the target current in the calibration process equals the current value of the electronic load, parameter saving begins.

[0095] The PC host computer sends a start calibration command (adjstart 1) to the calibration fixture via the UART interface;

[0096] After receiving the instruction, the calibration fixture outputs a specific voltage sequence of 5V, 9V, 7V, 2V, and 10V to the dimming interface of the LED power supply at 100ms intervals.

[0097] The dimming power supply converts analog signals into ADC digital signals in real time and saves them to five built-in temporary storage units through a shifting algorithm.

[0098] The five built-in temporary storage units compare the current output within a fixed precision range (e.g., ±0.2V) to see if the sequence requirements of 5V, 9V, 7V, 2V, and 10V are met. If the requirements are met, the current PWM duty cycle (e.g., 89.3%) is recorded as the maximum current output value and saved to the built-in flash memory.

[0099] Exit the calibration process. For subsequent 0-10V input signals, the power supply will be mapped to the output from 0 to the recorded maximum PWM duty cycle value.

[0100] This invention achieves power supply current calibration on a standard microcontroller through a single 0-10V analog interface, solving the microcontroller selection problem. It allows for the introduction of lower-cost microcontrollers into dimmable power supplies, reducing hardware material costs. An automated, closed-loop calibration process eliminates calibration errors caused by human intervention; this automated calibration scheme saves labor and time costs and avoids human error.

[0101] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A system for calibrating the current of a constant voltage adjustable LED power supply, characterized in that: The system comprises a calibration fixture, a power supply under test, an electronic load, and a host computer, connected sequentially to form a complete closed loop for automated calibration of a constant voltage adjustable LED power supply. The host computer is used to initiate calibration commands to the calibration fixture, and is also used to set a target current and initiate calibration commands to the calibration fixture according to the target current; or in response to the current reading of the electronic load, formulate an adjustment strategy for the calibration current according to the difference between the target current and the current reading of the electronic load, and initiate calibration commands to the calibration fixture according to the adjustment strategy; wherein, the adjustment strategy includes the adjustment direction and adjustment step of the calibration current; The calibration fixture is used to convert the digital instructions of the host computer into analog signals and output them to the power supply under test at a frequency agreed upon with the power supply under test. The power supply under test is used to convert the analog signal sequence received from the calibration fixture into a digital signal, and to perform corresponding operations based on the content of the digital signal; The electronic load is used to receive the output current of the power supply under test and send its own current value to the host computer for response and decision-making. The system performs the following calibration steps to calibrate the LED power supply current: S1. Start calibration: Set the target current on the host computer and initiate a calibration command to the calibration fixture according to the target current; S2. Entering Calibration Mode: After receiving the calibration command, the calibration fixture converts the digital command received from the host computer into an analog signal and outputs a predetermined voltage sequence of 0-10V to the dimming interface of the power supply under test at preset time intervals. The power supply under test converts the analog signal sequence received from the calibration fixture into a digital signal. In response to the predetermined voltage meeting the preset voltage sequence requirements, it enters the calibration mode. The preset voltage sequence is a specific voltage sequence of 9V, 5V, 2V, 7V, and 10V. S3. Current adjustment strategy determination: The host computer acquires the current value of the electronic load at a preset period, responds to the difference between the target current and the current value of the electronic load, determines the adjustment strategy of the calibration current, and sends the calibration command of the adjustment strategy to the calibration fixture. Based on the adjustment strategy received by the calibration fixture, the corresponding voltage sequence is parsed through instructions and output to the power supply under test through the 0-10V output interface; the power supply under test receives different voltage sequences and parses them, and adjusts the output current accordingly, including 1) reducing the duty cycle by 1%; 2) reducing the duty cycle by 0.1%; 3) increasing the duty cycle by 1%; 4) increasing the duty cycle by 0.1%. S4. Current Adjustment: In response to the calibration fixture receiving the calibration command of the adjustment strategy, a preset voltage sequence is output to the dimming interface of the power supply under test; the power supply under test receives the preset voltage sequence and analyzes it, and adjusts the output current accordingly so that the electronic load is adjusted towards the target current. S5. Repeat steps S3 to S4 until the target current equals the current of the electronic load, then start the parameter saving process. The parameter saving process includes: When the target current in the calibration process is equal to the current value of the electronic load, parameter saving is started, and the current duty cycle of the PWM is recorded as the maximum current output value. Exit the calibration process. For subsequent 0-10V input signals, the power supply under test will be mapped to the output from 0 to the recorded maximum PWM duty cycle value.

2. The system for calibrating the current of a constant voltage adjustable LED power supply according to claim 1, characterized in that: The power supply under test includes a 0-10V dimming interface and a direct-connect output interface. The dimming interface is connected to the calibration fixture and is used to receive analog signals. The direct-connect output interface is connected to the electronic load and is used to output current.

3. The system for calibrating the current of a constant voltage adjustable LED power supply according to claim 1, characterized in that: In step S2, after the calibration system enters the calibration mode in response to the calibration, the power supply under test will start from a fixed PWM duty cycle.

4. The system for calibrating the current of a constant voltage adjustable LED power supply according to claim 1, characterized in that: In step S3, the difference between the target current and the current value of the electronic load is used to formulate an adjustment strategy for the calibration current, including: 1) If the target current is much greater than the current value of the electronic load, send adjdec10 to the calibration fixture; 2) If the target current is greater than the current value of the electronic load, send adjdec1 to the calibration fixture; 3) If the target current is much less than the current value of the electronic load, send adjinc10 to the calibration fixture; 4) If the target current is less than the current value of the electronic load, send adjinc1 to the calibration fixture; 5) If the target current is equal to the current value of the electronic load, start the parameter saving process; where the absolute value of "much greater than" or "much less than" is greater than 0.1A, and the absolute value of "much greater than" or "much less than" is between 0 and 0.1A.

5. The system for calibrating the current of a constant voltage adjustable LED power supply according to claim 4, characterized in that: Step S3 includes: 1) Upon receiving the adjdec10 command, the calibration fixture outputs a specific voltage sequence of 2V, 7V, 2V, 7V, and 10V to the dimming interface of the power supply under test at 100ms intervals; 2) Upon receiving the adjdec1 command, the calibration fixture outputs a specific voltage sequence of 7V, 2V, 7V, 2V, and 10V to the dimming interface of the power supply under test at 100ms intervals; 3) Upon receiving the adjinc10 command, the calibration fixture outputs a specific voltage sequence of 6V, 3V, 6V, 3V, and 10V to the dimming interface of the power supply under test at 100ms intervals; 4) Upon receiving the adjinc1 command, the calibration fixture outputs a specific voltage sequence of 3V, 6V, 3V, 6V, and 10V to the dimming interface of the power supply under test at 100ms intervals.

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