Transformer
![Pole-mounted distribution transformer with center-tapped secondary winding used to provide 'split-phase' power for residential and light commercial service, which in North America is typically rated 120/240 V.[1][2]](/Images/godic/202501/10/Polemount-singlephase-closeup2956.jpg")
![Ideal transformer connected with source VP on primary and load impedance ZL on secondary, where 0 < ZL < ∞.](/Images/godic/202501/10/Ideal_Transformar2956.png")
![Ideal transformer and induction law[lower-alpha 5]](/Images/godic/202501/10/Transformer3d_col3.svg2956.png")
![Instrument transformer, with polarity dot and X1 markings on LV side terminal](/Images/godic/202501/10/Instrument_Transformer2956.jpg")
A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. Electromagnetic induction produces an electromotive force within a conductor which is exposed to time varying magnetic fields. Transformers are used to increase or decrease the alternating voltages in electric power applications.