A slip ring passes electrical signals and power across a rotating interface using sliding electrical contacts. These contacts are typically a rotating ring and a stationary brush, or wiper, that slides along the ring surface during rotation. Usage - A slip ring is a method to make an electrical connection from a stationary object to a rotating assembly. These are used in many industrial automation applications and for equipment like tower and jib cranes, as well as cable and hose winders, where a portion can spin freely, while the base is fixed Advantages of rotary slip ring - High stability. Mercury slip rings are the same in terms of performance as other electric slip rings. ...Economical. ...Low maintenance. ...Low contact resistance. ...Long service life. ...Beautifully designed. ...Easy to handle. ...Higher current conductivity.