Electromagnetic induction
Faraday's law: the physical principle that makes every transformer work.
Definition
Electromagnetic induction is the phenomenon by which a magnetic flux varying through a circuit generates an electromotive force (a voltage) within it. Discovered by Michael Faraday in 1831, it is the founding physical principle of the electrical transformer.
In a transformer, the alternating current in the primary creates a varying magnetic flux in the core. This flux passes through the secondary winding and induces a voltage in it, proportional to the number of turns and to the rate of change of the flux. It is this purely magnetic coupling — without any electrical contact — that transfers energy from one circuit to the other.
Lenz’s law specifies the direction of the induced voltage: it always opposes the change in flux that creates it, ensuring conservation of energy.
The ABL tip
Induction only works with alternating current: a transformer does not operate on DC. If your need involves direct current, you require a DC/DC converter — our engineers will point you to the right technology.
