An alternator (alternating-current generator or AC generator) is a device that induces an alternating emf in a coil. The coil rotates with constant angular velocity inside a constant and uniform Magnetic Field.
Applying Faraday’s law
$$ \mathcal{E}=-\frac{d \Phi_{B}}{d t}=-\frac{d}{d t}(B A \cos \omega t)=\omega B A \sin \omega t $$- The alternator converts mechanical rotational energy into electric energy.
- A commutator or a rectifier is needed to produce direct current (DC), exactly as in the DC motor.
