Direct current

This refers to a state in which electric current flows in only one direction and voltage is applied in only one direction within a conductor such as an electric wire. Generally, the magnitude of the voltage is often constant, but there are cases where it varies, such as full-wave rectified waveforms, half-wave rectified waveforms, and pulsating waveforms. Compared to alternating current, direct current has advantages such as the absence of reactive power and skin effect, allowing effective use of electric wires. On the other hand, it has disadvantages, such as difficulty in changing the magnitude of voltage and current. While alternating current is mainly used in power transmission and distribution circuits that handle large amounts of power, direct current is mainly used in electronic circuits that handle small amounts of power.