300W DC-DC Step Down Adjustable Power Supply Buck Module 7V~40V to 0.8V~28V Features: Indicator light current is 0.1 times of the current which is used to identify whether it is fully charged. Made from special IC and high accuracy sampling resistors which ensures a more stable constant current, specially fit LED driver. Four high frequency capacitors can reduce output ripple and good for stability. Two independent heat sink design are better for heat dissipation. The inductor of large sendust core and double copper wiring would improve efficiency and decrease heat. Widely used for high power LED drive, lithium or lead-acid battery, low voltage system power supply, 6V, 12V, 14V, 24V battery charging and regulated power supply. When power tube temperature is over 65℃, please add cooling fan to enhance heat dissipation. Specifications: Type Non-isolated step-down module (DC-DC) Input Voltage DC 7V to 40V Output Voltage DC 0.8V to 28V (continuously adjustable) Output Current 0.2A to 8A(adjustable, <6A when 24V to 12V), 8A is suggested Min. Voltage Difference 1V Max. Output Power 300W Max. Conversion Efficiency 95% Frequency 300KHZ Output Ripple 20M bandwidth Output Short Circuit Protection Yes (constant current) Reverse Electrode Protection No Output Backflow Protection No Wiring Method Terminals No-load Current 20mA (24V switch, 12v) Load Regulation ± 1% (constant) Voltage Regulation ±1% Dynamic Response Speed 5%200uS Potentiometer Adjustment Clockwise to increase and counterclockwise to reduce Operating Temperature -40℃ to +85℃ Indicator Light Red color charging; green color charging finished or no load Constant Current and Constant Temperature Accuracy <5%, 5A from 25℃ to 60℃ Output Short Circuit Protection Yes (constant current) Reverse Input Protection No Output Backflow Protection No Size 64 x 47 x 23.5mm / 2.52 x 0.85 x 0.92"   Instruction: Battery Charge: 1. Make sure of the battery float voltage and charging current that you need, as well as the input voltage of the module. 2. Adjust the constant voltage potentiometer and adjust the output voltage to about 5V. 3.Use the multimeter in 8A current scale to measure output short-circuit current, and adjust the current potentiometer to make the output current to the expected charging current value. 4. Adjust the constant voltage potentiometer to make the output voltage reaches the float voltage. 5. Connected to the battery, try to charge. (1,2,3,4 steps to connect the power module input,output no-load does not connect battery.) LED Constant Current Drive: 1. Make sure the operating current and Maximum operating Voltage of the LED you need to drive. 2. Adjust the constant voltage potentiometer, adjust the output voltage to about 5V. 3. Use the multimeter in 8A current scale to measure output short-circuit current, and adjust the current potentiometer to make sure the output current to the expected LED operating current. 4. Adjust the constant voltage potentiometer to make the output voltage reach the maximum LED operating voltage. 5. Connect LED, test. (1,2,3,4 steps to connect the power module input, output No-load does not connect LED.) Package Includes: 1 x Module