The electric transformers are most commonly used for increasing low AC voltages at high current (a step-up transformer) or decreasing high AC voltages at low current (a step-down transformer) in electric power applications, and for coupling the stages of signal-processing circuits. In the case of electrical utilities in homes, they use transformers to change the voltage of electricity as it travels from the power plant to the home. They are an electrical apparatus designed to convert alternating current from one voltage to another. Electric transformers are commonly recognized, there are other various types and sizes as well. They are very powerful.