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
50hzin most of the rest of the world.
- Amplitude - This is the magnitude of the waveform and is usually measured in volts or amps.
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.