This is a DC-DC step-down buck converter power supply module based on the LM2596 Buck Converter IC. Most of the sensors, Development Boards like Arduino, Raspberry Pi, and PIC Controllers work on either 5V or 3.3V, most commonly available battery we have with us is 9V or 12V lead-acid batteries so it is essential that we supply the components with correct voltage, otherwise, they may misbehave or simply not work at all. Also, fluctuations in power supply will result in errors and garbage data from the sensors. It may also corrupt the SD card on which you are writing the data or cause your program to misbehave. The module has an input voltage from 4V to 35V and stepped down-regulated output voltage from 1.25V to 30V. It operates on 150kHz switching frequency. The output voltage can be set by rotating the on-board blue color potentiometer. The main advantage of this module is that it can provide a high output current of up to 3A so that you can even connect small motors to it without thinking much but keep an eye on the heat dissipation of the module.