vaihtovirtojen

Vaihtovirta, often abbreviated as AC (alternating current), is an electric current that periodically reverses direction, in contrast to direct current (DC), which flows only in one direction. The defining characteristic of AC is its cyclical nature, typically represented by a sine wave. This means the voltage and current oscillate between positive and negative values over time.

The primary advantage of AC over DC is its ease of voltage transformation. Alternating current can be efficiently stepped up or down using transformers. This ability is crucial for power transmission. Electricity is generated at relatively low voltages, stepped up to very high voltages for efficient long-distance transmission with minimal power loss, and then stepped down again to safer, usable levels for homes and industries.

Nikola Tesla is widely credited with developing and advocating for the AC electrical system, which ultimately became the dominant standard for power distribution worldwide. Key components of an AC circuit include resistance, capacitance, and inductance, which all influence the flow of current and the phase relationship between voltage and current. The frequency of the AC, measured in Hertz (Hz), indicates how many cycles occur per second. Common frequencies include 50 Hz and 60 Hz.