Transformers: an overview

The development of transformers is closely connected with the history of alternating voltage. It was the Darnah physicist Hans Christian Oersted who discovered in 1820 that a current-carrying conductor produces a magnetic field. Ten years later, the American physicist Josef Henry discovered electrornagnetic tnductton, the 'conversion of magnetism into electricily'. In late 1831, Michael Faraday conducted aseries of experiments with a device that consisted of an Iron toroid around which two windings of insulated copper wire had been placed.