DC Buck Converter LM2596 DC-DC Power Module LED Display Power Supply Adjustable Step-Down Converter 4.0-40V Voltage Regulator Features: 1. Includes a voltmeter display with ±0.1V accuracy, measuring range 4-40V. (Note: Input voltage below 4V will not activate the onboard voltmeter.) 2. Large touch button allows switching between input and output voltage measurement. Indicator lights show which voltage is being measured. Default display shows input voltage with "IN" indicator lit. Press the button to switch to output voltage display with "OUT" indicator lit. Settings are saved even after power cycle. 3. Voltmeter can be turned off by pressing and holding the switch for more than 1 second but less than 4 seconds. To reactivate, simply press the button once. 4. Equipped with terminal blocks for easy connection without soldering. Wire bonding points are retained. (Input voltage must be at least 1V higher than the desired output voltage.) 5. Operates at 150kHz internal oscillation frequency, part of the second-generation switching regulator technology, offering low power consumption and high efficiency. 6. Input端 features diode protection; reverse polarity will not damage the module. 7. Built-in overheat and short-circuit protection. (For loads above 15W, additional heat dissipation is recommended.) How to Calibrate Output Voltage: Step 1: Press the right button until "OUT" LED is lit to display output voltage. Press and hold the right button for more than 2 seconds, then release. The display and "OUT" LED will flash, indicating entry into calibration mode. Step 2: Press the right button to increase voltage in small increments; press the left button to decrease. Although each step is less than 0.1V, the display updates in 0.1V increments depending on current voltage level. Higher voltages require fewer presses per 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 automatically saved. Specifications: Input Voltage: 2.5V–40V Output Voltage: 1.25V–37V (adjustable) Output Current: Up to 3A Conversion Efficiency: Up to 92% Output Ripple: Low noise design