Where would we be without alternating current (AC)?
Hey! Here is the surprising answer to your question: almost ALL of the electronic devices you use everyday is powered by DC! From your wrist-watch to Ipod to laptop to TV to cellphone to you name it – it is all powered by DC. Most electrical vehicles (trains as well as hybrid/EV cars) use DC drive-trains. Very few devices are engineered to use AC (such as poorly designed radio-alarms that tap off the frequency to keep time). As all the posters above have noted, it was problems with transmission losses due to the inability to set-up DC to a high voltage that prevented the widespread use of DC. Today, we have several high-voltage DC links in the world, including in USA. High voltage DC transmission has a very powerful reason going for it – it isolates two different regions that might experience dynamic instability when linked with an AC link.
