As you may know, the electric supply in our homes is based on ‘alternating current’ or AC, in short. Batteries on the other hand, have ‘direct current’, or DC.
In fact, it was all DC when the supply of electricity began, including the first long-distance transmission system. When Edison developed his incandescent bulb, it needed an electric distribution system. The first commercial dynamo, a DC generator, became available during that time. This led Edison to develop a lot of devices which the DC electric system needed. Soon, more than 200 electric companies in America were paying him patent royalties.
Picture Credit : Google
