/ˌdiː ˈsiː/
noun … “Electric current that flows in one direction.”
DC, short for Direct Current, is a type of electrical current in which electric charge flows consistently in a single direction. Unlike alternating current, where the direction of flow periodically reverses, DC maintains constant polarity, making it especially suitable for electronic circuits, digital systems, and energy storage.
DC is the natural form of electricity produced by sources such as batteries, solar cells, and fuel cells. Inside electronic devices, even those powered from AC wall outlets, electricity is almost always converted to DC using a rectifier and stabilized with a voltage regulator.
Key characteristics of DC include:
- Unidirectional flow: current moves in only one direction.
- Constant polarity: voltage does not alternate sign.
- Stable voltage levels: ideal for logic and control circuits.
- Energy storage compatibility: easily stored in batteries and capacitors.
- Low noise: preferred for sensitive electronic components.
Common uses of DC include powering microcontrollers, CPUs, memory, sensors, motors (with control electronics), and communication devices.
Workflow example: Supplying DC to a circuit:
battery_voltage = 9
regulated_voltage = voltage_regulator.set(5).apply(battery_voltage)
circuit.power(regulated_voltage)
Here, DC from a battery is regulated to a lower, stable voltage suitable for digital electronics.
Conceptually, DC is like water flowing steadily through a pipe in one direction, without reversing or pulsing back and forth.
See AC, Power Supply, Rectifier, Voltage Regulator, Battery.