Transformer From Anand Prasad, Assistant Engineer, APEPDCL , Rajahmundry This article is about the electrical device. For the toy line franchise, see Transformers . For other uses, see Transformer (disambiguation) . Pole-mounted distribution transformer with center-tapped secondary winding. This type of transformer is commonly used in the United States to provide 120/240 volt " split-phase " power for residential and light commercial use. Note that the center "neutral" terminal is grounded to the transformer "tank", and a grounded conductor (right) is used for one leg of the primary feeder. A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying...