ABSTRACT
Until now, we have considered only ideal, lossless transformers obeying the fundamental transformer laws: Voltages and currents are transformed strictly according to the transformer turns ratio, and the power output from the transformer is equal to the power input to the transformer. The conditions expressed by the ideal transformer laws are approached, but never realized in physical transformers. Transformed voltages and currents are always less than the values predicted by the turns ratio because of losses. This chapter explains the origins of transformer losses and develops the concept of equivalent circuits of real transformers.
