Adjustable POWER MODULE LM2596S DC-DC Buck Regulator Converter Reduced Voltage Regulator Power Module 24V 12V To 5V 2A Features: 1. Equipped with a voltmeter display, voltmeter error 0.1V, range 4 ~ 40V. (Note: if input voltage is below 4V, the onboard voltmeter does not operate and will not display) 2. Large 5x5 touch button to switch between input and output voltage measurement, with indicator light showing which voltage is being measured. Default display shows input voltage with "IN" indicator lit; pressing the button switches to output voltage display with "OUT" indicator lit. Settings are saved even after power cycle. 3. Voltmeter can be turned off by long-pressing the switch for more than 1 second and less than 4 seconds. Press the button again to turn the voltmeter back on. 4. Includes terminal block for easy connection without soldering, while maintaining wire connection points. (Input voltage must be at least 1V higher than desired output voltage) 5. Uses 150kHz internal oscillation frequency, part of the second-generation switching voltage regulator technology, offering low power consumption and high efficiency 6. Input端 with diode protection to prevent damage from reverse polarity connection 7. Includes overheat protection and short circuit protection (for loads over 15W, additional heat dissipation is recommended) Output Voltage (Input Voltage) Calibration Steps: Step 1: Press the right button until the "OUT" ("IN") LED is lit, indicating output (input) voltage is displayed. Press and hold the right button for more than 2 seconds, then release. The voltmeter and "OUT" ("IN") LED will flash simultaneously, entering calibration mode. Step 2: Press the right button (at normal speed) to increase voltage by one unit; press the left button to decrease by one unit. Since one unit is less than 0.1V, multiple presses (1–5 times) may be required to observe a 0.1V change on the display. The number of presses needed depends on the current voltage level—higher voltages require fewer presses for a 0.1V change. Step 3: Press and hold the right button for more than 2 seconds, then release to exit calibration mode. All settings are saved automatically. Specifications: Input voltage: 2.5V ~ 40V Output voltage: 1.25V ~ 37V (adjustable) Output current: up to 3A Conversion efficiency: up to 92% Output ripple: 50mV (maximum)