21. Today speed control by use of slip ring motor is mostly superseded by induction motors with variable-frequency drives. 22. A slip ring can be used in any electromechanical system that requires rotation while transmitting power or signals. 23. The other part is AC current from the slip rings which is directly rectified into DC by the commutator. 24. Also, motor generators require more routine maintenance due their nature as rotating machines, given the bearings and slip rings . 25. To reduce the electrical noise the contact points need to be pressed against the slip rings with greater force. 26. A two-phase rotor winding is connected to the incoming machine source by a phase-shifting network through brushes and slip rings . 27. In addition, where signals and power need to pass to the model, some form of slip ring arrangement is required. 28. Full free rotation would require slip rings around each gimbal axis for power conductors, further adding to the design complexity. 29. Doubly fed electric machines use the slip rings to supply external power to the rotor circuit, allowing wide-range speed control. 30. A slip ring ( in electrical engineering terms ) is a method of making an electrical connection through a rotating assembly.
