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Electrical & Electronics Engineering vocabulary · Voltage, Current and Power

AC

Meaning in electrical & electronics engineering, with examples

/ˌeɪ ˈsi/abbreviationCore term

In electrical & electronics engineering, AC means: Short for alternating current: current that changes direction many times per second. Mains electricity is AC, at 50 Hz in Turkey and Europe and 60 Hz in North America.

In Turkish: alternatif akım, AA

How it is used

Pronounced as two letters, 'A-C'. Used on its own and before nouns: AC voltage, AC supply, AC motor, the AC side. Meters and labels show it as 'V~' or 'VAC'. In everyday English AC also means air conditioning, so context matters.

Example sentences

  1. The unit runs on 230 V AC and has a built-in power supply.

  2. Set the meter to AC volts before you measure the socket.

Common collocations

  • AC voltage
  • AC supply
  • AC motor
  • AC side
  • AC-DC converter
  • DCShort for direct current: current that flows in one direction only, usually at a steady value. Batteries, solar panels and most electronic circuits work with DC.
  • frequencyThe number of times a signal repeats its cycle in one second, measured in hertz (Hz). Mains electricity in Turkey has a frequency of 50 Hz.
  • RMSShort for root mean square: the effective value of an AC voltage or current, equal to the DC value that would deliver the same power. A mains voltage of 230 V is an RMS value.
  • transformerA device that transfers AC power from one winding to another through a shared magnetic core, usually to step the voltage up or down. It does not work with DC.
  • rectifierA circuit or device that converts AC into DC, usually with diodes. A bridge rectifier uses four diodes so that both halves of the AC waveform are used.

More terms: Voltage, Current and Power

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