LTC1871 DC-DC Boost Step-up Voltage Converter Module 100W High Power Adjustable Output 3.5-35V Power Regulator Board with LED Voltage Meter. Automatic boost module provide a stable power supply.Applicable to unstable voltage source or voltage conversion. Use manual: Connect load at OUT+ and OUT- at first.Please note the positive and negative. Connect power supply at IN+ and IN-.Please note the positive and negative. Press the button to switch the display input or output voltage value. Warm tip: When the high power load is connected, because the shock current of the start-up is very limited, it is recommended to start up and then connect the load. Application: DIY a regulated power supply, 5V input can be output 5-35V adjustable. The power supply for your electronic equipment. For example, 3.7V lithium boost to 5V for mobile power; 7.4V or 12V boost to the laptop power supply to 19V. As the vehicle power supply for your laptop, PDA or a variety of digital products supply.