AC electricity is described in terms of period, frequency, and amplitude.

  • Period - Period is the amount of time that it takes the waveform to make one complete cycle.
  • Frequency - Measured in hertz (hz), frequency is the number of time the waveform repeats itself in one second. In the United States, this is usually 60hz, and 50hz in most of the rest of the world.
  • Amplitude - This is the magnitude of the waveform and is usually measured in volts or amps.

Other Waveforms

Alternating current is not always a perfect sine wave. In fact, alternating currents are often generated digitally by using triangle and square waves:

Sometimes, even more complex waveforms are generated, usually by adding other waveforms on top of an existing carrier wave, in what’s known as modulation:

In fact, this is how radio transmissions work! A message signal is added to a carrier signal, for instance 107.7Mhz, then a radio receiver “tunes” into that particular frequency of carrier signal, and then subtracts it from the transmission, leaving only the message signal.

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