Manufacturers introduce various new forms and styles, but for the most part decoration and fashion concerns are limited to the face-plates or wall-plates. It is not unusual to see century-old light switches still in functional use. Switches typically remain in service for many decades, often being changed only when a portion of a house is rewired. The dimensions, mechanical designs, and even the general appearance of light switches have changed slowly over time.
Hence, the shape and size of the boxes and face-plates, as well as what is integrated, varies from country to country. Since the face-plates used must cover this hardware, these standards determine the minimum sizes of all wall mounted equipment. In different countries the standard dimensions of the wall mounting hardware (boxes, plates, etc.) may differ. Īs a component of an electrical wiring or home wiring system, the installation of light switches is regulated by some authority concerned with safety and standards. The toggle light switch was invented in 1916 by William J. This "quick break" technology is still in use in almost every ordinary light switch in the world today, numbering in the billions, as well as in many other forms of electric switch. The action of this "quick break" mechanism meant that there was insufficient time for an arc to form, and the switch would thus have a long working life. Holmes' invention ensured that the contacts would separate or come together very quickly, however much or little pressure was exerted by the user on the switch actuator. Arcing would cause pitting on one contact and the build-up of residue on the other, and the switch's useful life would be diminished. The "quick-break" switch overcame the problem of a switch's contacts developing electric arcing whenever the circuit was opened or closed. The first light switch employing "quick-break technology" was invented by John Henry Holmes in 1884 in the Shieldfield district of Newcastle upon Tyne. The switch box is covered by a decorative plate. The switch on the right is a dimmer switch. These covers are usually quite easy to mount. Wall plates are available in different styles and colours to blend in with the style of a room, also available in weatherproof varieties for outdoors. Each kind uses some form of a plastic, ceramic, or metal cover to prevent accidental contact with live terminals of the switch. These light switch boxes (a pattress box) are designed to house and mount the switch(s), protect the wiring and contain any heat or fire. Surface mounting of enclosures is also fairly common though is seen more in commercial industrial and outbuilding settings than in residential structures.
The switch mounting boxes, or enclosures are often recessed within a finished wall. Mounting height, visibility, and other design factors vary from country to country. Residential and commercial buildings usually have wall-mounted light switches to control lighting within a room. Switches for lighting may be in hand-held devices, moving vehicles, and buildings.
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