Since it is not a hard thing for one to connect power to your piece of electronics with a DC pigtail, here are variable steps to follow. You are going to always want to identify the voltage and current type associated with your device to make sure it will work with both the power supply and the pigtail cable. The DC barrel connector on the pigtail should match the input port on your device, usually specified by diameter and pin size. Once the barrel end is attached to your device, the bare wire leads on the other end can be connected to a DC power source by soldering a lead to a circuit board, by using a screw terminal, or even by connecting them to a battery with appropriate terminals. Be certain to check the polarity to avoid damage to your device. A DC pigtail, when treated accordingly, can provide one with a stable and safe power connection.