Alternating current

lightbulb

Alternating current

Alternating current (AC) is a type of electrical current that periodically reverses direction, resulting in the flow of electrons changing its direction back and forth in a conductor. Unlike direct current (DC), AC does not maintain a constant flow of electrons in one direction.

What does Alternating current mean?

Alternating current (AC) is an electrical current that periodically reverses its direction. In alternating current, the direction of the flow of electric charge reverses at regular intervals or cycles. AC is produced by alternating current generators, typically powered by alternating current motors or engines.

Alternating current is commonly used in electrical power systems, where it is generated at power plants, distributed through power lines, and converted to Direct current (DC) for use in homes and businesses. AC power is used to power motors, lights, heating systems, and other electrical devices.

Applications

Alternating current is used in various applications due to its advantages over direct current (DC):

  • Power transmission: AC is more efficient than DC for transmitting power over long distances. This is because AC can be stepped up to very high voltages, reducing power loss due to resistance in transmission lines.
  • Transformers: AC can be easily transformed from one voltage to another using transformers, which are not possible with DC. Transformers allow AC to be distributed at different voltages to suit various applications.
  • Motors: AC motors are more efficient and reliable than DC motors, particularly for high-power applications. AC motors are widely used in industrial machinery, appliances, and electric vehicles.
  • Induction heating: AC is used in induction heating systems to generate heat in conductors without direct contact. This technique is used in various applications such as metalworking, heat treating, and cooking.

History

The development of alternating current began in the late 19th century with the invention of the induction generator by Michael Faraday. However, it was Thomas Edison who First developed a practical alternating current system for lighting in the 1880s.

Edison’s alternating current system initially faced competition from Nikola Tesla‘s polyphase alternating current system, which was more efficient and could transmit power over longer distances. In the late 19th and early 20th centuries, a fierce “War of Currents” ensued between Edison’s DC system and Tesla’s AC system.

Ultimately, AC power prevailed due to its advantages in power transmission and efficiency. Today, AC is the dominant Form of electrical power used worldwide.