shading ring

shading ring

[′shād·iŋ ‚riŋ]
(electromagnetism)
The copper ring used in a shaded-pole motor to produce a rotating magnetic field for starting purposes, or used around a part of the core of an alternating-current relay to prevent contact chatter. Also known as shading coil.
(engineering acoustics)
A heavy copper ring sometimes placed around the central pole of an electrodynamic loudspeaker to serve as a shorted turn that suppresses the hum voltage produced by the field coil.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
References in periodicals archive ?
The valve has a brass body, fluorocarbon seals, NB1K diaphragm, copper shading ring, and stainless steel sleeve, plunger, and springs.