AC/DC power supplies convert AC power to DC power. In the Americas, the single phase AC line voltage is 120V with a line frequency of 60Hz. In Europe the single phase line voltage is between 220V to 240V with a line frequency of 50Hz. However, in Asia, the line voltages and frequencies vary in different regions and countries. Even though the electric power is transmitted in AC form, all electronic devices/appliances are operating with DC. Therefore, a conversion from AC power to DC power is required.