Consumer Electronics

IMPEDANCE MATCHING

It will be useful to give a simple recapitulation of transformer theory. A transformer represents a straight forward application of the phenomenon known as electromagnetic induction, whereby any change in the magnetic flux linking an electric circuit is accompanied by an induced electromotive force in that circuit. The value of this induced voltage will, at any instant, be proportional to the rate of change of the flux, while its direction will always be such as to oppose the change producing it. The change of linkages may be produced by movement of the electric circuit with respect to a magnetic field which is constant, as in a dynamo, or by varying the current in a stationary electric circuit. When the induced emf produced ...