Tasasähköä

Tasasähköä, also known as direct current (DC), is an electric current that flows in only one direction. This is in contrast to alternating current (AC), where the direction of the current periodically reverses. In a DC circuit, electrons flow from the negative terminal to the positive terminal of a power source.

Historically, DC was the first form of electricity to be widely used. Early electrical systems, such as those developed by Thomas Edison, relied on DC power. However, DC has limitations in transmitting electricity over long distances due to voltage drop. AC, with its ability to be easily transformed to higher voltages for efficient transmission and then stepped down for use, became the dominant form of electricity distribution.

Despite the prevalence of AC, DC power remains crucial for many applications. Batteries, for instance, store and deliver energy as DC. Many electronic devices, including computers, smartphones, and LED lights, operate on DC power. Therefore, these devices incorporate internal power supplies or adapters that convert AC from the grid into the necessary DC voltage. In certain industrial applications and for high-voltage direct current (HVDC) power transmission, DC is also utilized.