open source charging pills are the emergency chargers which ensures our device is powered safely without any issues.Basically we are converting a voltage source to a voltage that is acceptable for our device to charge up without any issues (4.7-5v) to this need we use VOLTAGE REGULATOR. As per the connections the circuit provides the required output.the outer design is miniature to reduce the size and portability. 3D printers helps us to satisfy that need.this is ma first CAD design so.. _/\_ hope u like ma first post.!!!!...TECH UPGRADING..!!!coming soon.