Miscellaneous Starting Devices

Author: E.E. Kimberly

In addition to the starting devices described, many special starters have been produced for special service. In one type, the field of the motor is constantly excited from one source of power while the armature is supplied by a variable-voltage generator. This method of multi-voltage control, called the Ward-Leonard system, while higher in cost than most others, provides extremely smooth acceleration and is used extensively in the control of high-speed elevators, mine hoists, etc. In another type of starter for small d-c motors, the series resistance consists of a stack of carbon discs the resistance of which is smoothly varied by pressure.