Profile: Mercotac, Inc. deals with rotating electrical connectors. Our rotating electrical connectors are developed to meet the needs of a variety of industrial machinery applications. Rotary electrical connectors offer an extremely low resistance electrical connection, because the electrical conduction path is a liquid metal which is molecularly bonded to the contacts. The Mercotac® connection is constant and unchanged for the life of the rotary electrical connector. Brush slip rings are usually composed of a rotating metal ring upon which a graphite or metal brush rubs and transfers the electrical signal or current.