Slip rings are used in rotating electrical components. To establish a continuous electrical connection between the fixed and moving conductors. This enables stationary power sources to transfer electrical energy to rotating components.

A slip ring is a strip of conductive material mounted on a shaft. Although insulated from the shaft itself. But, slip rings are connected to the rotor or rotating components through windings . Or other electrical connections. The outside of the slip ring is in continuous sliding contact with a fixed brush. Or other fixed conductor.

Slip rings are used as a way to provide DC excitation to the rotor of an alternator. After the alternator output is rectified, the DC power we generate is fixed. But the direct current to be fed is rotating. Thus, we take out the rotor terminal and attach a slip ring that rotates with the shaft at its end. The brushes feeding DC power are kept in contact with the rotating slip ring. When the slip ring passes over the brush, DC power is fed into the rotor winding. We can consider the slip ring and brush arrangement. As the interface between the rotating rotor and the fixed DC power supply.