Slip ring

In electrical engineering, a slip ring is a method of making an electrical connection through a rotating assembly. Slip rings are commonly found in electrical generators for AC systems, alternators and similar.

A slip ring consists of a conductive circle or band mounted on a shaft but insulated from it. Electrical connections from the rotating part of the system (such as the rotor of a generator) are made to the ring. Fixed contacts or brushes run in contact with the ring, transferring electrical power or signals to the exterior non-rotating part of the system.

Note that this is a similar but different system to that of the brushes and commutator found in many types of DC motor.

Slip rings can also be used where electrical power or signals need to be transferred to a rotating device, such as a rotating beacon light, etc. They could also be used in systems such as the tape head of a helical scan video system, though in practice those devices use non-contacting methods of transferring the signal.