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In building wiring, multiway switching is the interconnection of two or more electrical switches to control an electrical load from more than one location. A common application is in lighting, where it allows the control of lamps from multiple locations, for example in a hallway, stairwell, or large room. In contrast to a simple light switch ...
Unlike ATEX which uses numbers to define the safety "Category" of equipment (namely 1, 2, and 3), the IEC continued to utilise the method used for defining the safe levels of intrinsic safety namely "a" for zone 0, "b" for zone 1 and "c" for zone 2 and apply this Equipment Level of Protection to all equipment for use in hazardous areas since ...
ATEX Directive 2014/34/EU was published on 29 March 2014, by the European Parliament. It refers to the harmonization of the laws of the Member States relating to equipment and protective systems intended for use in potentially explosive atmospheres. Regarding ATEX 99/92/EC Directive, the requirement is that Employers must classify areas where ...
Vintage push-button light switches. The push-button light switch has two buttons: one that closes the contacts and one that opens the contacts. Pushing the raised button opens or closes the contacts and pops out the previously depressed button so the process can be reversed. In the U.S., the buttons were commonly black; the "on" button ...
These common lighting qualms have to do with the color temperature of the light bulbs. While many people may look at wattage (i.e., the amount of energy that a bulb uses to produce light) before ...
Fluorescent lamp tubes are often straight and range in length from about 100 millimeters (3.9 in) for miniature lamps, to 2.43 meters (8.0 ft) for high-output lamps. Some lamps have a circular tube, used for table lamps or other places where a more compact light source is desired.
Power semiconductor device. A power semiconductor device is a semiconductor device used as a switch or rectifier in power electronics (for example in a switch-mode power supply ). Such a device is also called a power device or, when used in an integrated circuit, a power IC . A power semiconductor device is usually used in "commutation mode" (i ...
From around 1905 to 1910 various mercury switches were invented, but the "mercury in glass envelope" switch got its start with patent 1598874 (filed on January 19, 1922 by Louis Phelan), [1] which evolved into a more modern mercury switch with a straight tubular glass envelope via patent 2232626 (filed on October 7, 1937 by Harold Olson of Honeywell).