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1. a device, such as a rheostat, for varying the current through an electric light and thus changing the illumination
a. a dipped headlight on a road vehicle
b. a parking light on a car
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
A solid-state device used to vary the voltage to a light fixture and thereby lower or raise the intensity of the light. Used mainly for incandescent lamps and fluorescent lamps with special ballasts. Also called a rheostat, it can be installed on a wall switch or directly into a lamp and can easily be added to existing installations.
Illustrated Dictionary of Architecture Copyright © 2012, 2002, 1998 by The McGraw-Hill Companies, Inc. All rights reserved
An electrical or electronic control for varying the intensity of a lamp or other light source.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
A device which varies the light intensity of a light source without appreciably affecting the spatial distribution of the light; usually an electric control device that varies the current flow and hence the light output of the lamp. dimmer room A room in which are located the dimmers for controlling the lights for an auditorium or theater.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.