The action of Transformer

A transformer is used to bring voltage up or down in an AC electrical circuit. Farady transformer can be used to convert AC power to DC power. There are transformers all over every house, farady ac power transformer is inside the black plastic case which you plug into the wall to recharge your cell phone or other devices. These types are often called "wall warts". They can be very large, as in national utility systems, or it can be very small embedded inside electronics. It is an essential part of all electronics today.