How does it work the transformer and generator?

A transformer use a varying voltage on one coil to impress a voltage on another coil by induction. Transformers cannot pass DC as a direct current does not have a varying voltage level. A power transformer connected to a wall outlet receives 120Volts AC (alternating current) at 60 Hertz (cycles per second) into it's primary coil. If it's a step down transformer with a 10-1 turns ratio a 12 VAC voltage will appear at the terminals of the secondary winding on the transformer. The windings (coils) are wound around an iron core to provide a circuit for the magnetic field and improve transformer efficiency. There are many different types of transformers in use, the type is dictated by the application the transformer is being used in. The theory of operation of Transformer