Which transformer winding is normally connected to the source power?

In a transformer, the primary winding is the one that is connected to the source power. This is where the input voltage is applied, and the alternating current (AC) flowing through this winding creates a magnetic field around the transformer core. This magnetic field induces a voltage in the secondary winding, allowing for the transformation of voltage levels. The primary winding typically has a greater number of turns than the secondary if the transformer is stepping down voltage.

The secondary winding, on the other hand, is where the induced voltage is taken for use in a circuit. It does not connect directly to the power source. Center tap refers to a configuration of the secondary winding that can provide multiple voltage outputs. Core winding is not a standard term associated with transformer functionality, as it generally relates to the magnetic core's role in facilitating the magnetic coupling between the windings rather than a specific winding itself.