vaihtovirtaiseen

Vaihtovirtaiseen refers to alternating current in Finnish. Alternating current, often abbreviated as AC, is an electric current that periodically reverses its direction. This is in contrast to direct current (DC), which flows in only one direction. The voltage of an AC waveform also reverses periodically.

The most common waveform for alternating current is a sine wave. The frequency of alternating current is typically measured in Hertz (Hz), which indicates the number of cycles per second. In most countries, the standard frequency for AC power grids is 50 Hz or 60 Hz. This means the current reverses its direction 100 or 120 times per second, respectively.

Alternating current is the form of electrical energy that is delivered by electric utilities to homes and businesses. This is because AC is easily converted to higher and lower voltages using transformers. High voltages are used for efficient long-distance transmission, and lower voltages are used for safety and compatibility with household appliances. Many electronic devices, however, require direct current for their operation, so they include power supplies that convert AC to DC.

The development of AC power systems is largely credited to Nikola Tesla and George Westinghouse. Their work in the late 19th century, including the invention of the AC induction motor, was crucial in establishing the widespread use of alternating current for power generation and distribution.