Alternating current is characterized by the fact that the electric current changes its direction periodically and in continuous repetition. This form of energy transmission is widely used in electrical energy supply. The frequency, measured in Hertz (Hz), indicates how often the direction of the current changes per second.
Generators and power stations use electromagnets to produce alternating current. This is how three-phase alternating current is generated. However, there is also single-phase alternating current, which is generated by bicycle dynamos.
The advantage of alternating current is that the applied voltage can be increased and decreased flexibly and with low losses using a transformer. This allows the voltage to be efficiently adapted to the requirements of different consumers.