If you’re reading this post, there’s a good chance you’re probably doing so on a device that’s powered using either direct or alternating currents. While these two types of currents both share the same basic function of moving energy from point A to point B, they do so in very different ways. For quite some time, the widespread use of either one of these currents was debated very heavily. Each side believed that one was superior to the other for various reasons, and history determined that both of them have a rightful place.
In an alternating current, the charge being sent between points periodically reverses direction. During a short amount of time, an alternating current will rise and fall above and below the line of absolute zero with periods of positive and negative energy transfer. Compared to DC, AC allows for more consistent transfer of energy over longer distances without any significant energy loss. It can also be generated and set at various voltage levels, allowing high amount of energy to be transformed to lower amounts of energy more suitable for home appliances and lighting.
Lights running on alternating currents tend to flicker at a rate that is beyond most people’s ability to perceive. Roughly 60 times per second, the amount of energy sent to an AC outlet hits zero.
Nikola Tesla favored the use of alternating currents due to their ability to maintain a charge over long distances.
Direct currents are more constant. Instead of delivering a fluctuating amount of positive and negative energy, with occasional drop in current, DC is constantly flowing in one direction. Direct currents are commonly used in battery-powered devices today. While mostly every home is now powered with AC, DC is considered the best mechanism for powering low-voltage, portable electronics. Solar applications are also powered through direct currents as they are presently incapable of producing alternating currents. DC is also predominantly used in most automotive applications. A car’s alternator produces an alternating current, but this is quickly transformed into a direct current through use of a rectifier. Most electronic systems require a DC current to operate. Power supplies are put in place to convert AC to DC in these cases.
Thomas Edison created the first electronic power transmission using direct currents.