DC is an acronym for direct current, which is a
flow of electricity that is unidirectional in nature. Sources like solar cells, batteries, and
thermocouples produce direct current.
One of the most widely known uses for DC current
is in automobiles. Almost all devices in a car are run on the car’s battery, which generates a DC
current.
The very first power transmission ever conducted
for commercial purposes used direct current. DC current, however, has been mostly replaced by AC
current for large scale power supply needs.
Alternating current has a lot of advantages over
DC current, especially in the areas of transmission and transforming.
If DC current is needed on any kind of wide scale, such as on a
third rail system, the AC power is routed to a substation and the power is passed through a massive rectifier. This
converts the AC current to DC current. DC
can also be turned into alternating current (AC) by using an inverter, which basically works in the opposite manner
of a rectifier.
In other applications, DC current is used widely for recharging
batteries, such as in a 24v DC power
supply, and in the power supplies of many different electronic devices. It is also used for some
railways, especially in areas that are very urban. DC current can also be used to send very large amounts of
electricity over distances or to connect AC power grids.
While DC usually means direct current, it can also be used to
refer to “constant polarity”. Direct current can flow through a wire, through a semiconductor, through an
insulator, or even though a vacuum as it does when being conducted through an electron beam.
Direct current used to be described as Galvanic current, though
this term was changed over time. Direct current is mainly different from alternating current in the way that it
only flows in one direction.