Direct current is the flow of electrons towards a single direction. It is very simple to visualize direct current using the “water circuit” model; simply think of water flowing towards one direction inside a pipe. Common devices producing direct current are solar cells, batteries and dynamo generators. Almost everything can be developed to be powered by a DC current source and it is almost exclusively used in any low voltage, mobile and electronics applications. DC current is pretty straightforward and almost everything is based on Ohm’s Law (V = I * R). The power of a DC load is measured in Watts and equals P = V * I (Watts).