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A staircase timer is an electrical switch used to control lighting on a staircase, corridor or lobby. A single action turns on the lights and they remain on for long enough to ascend or descend the stairs.
For example, a watchdog timer may be used when running untrusted code in a sandbox, to limit the CPU time available to the code and thus prevent some types of denial-of-service attacks. [2] In real-time operating systems , a watchdog timer may be used to monitor a time-critical task to ensure it completes within its maximum allotted time and ...
The timer may switch equipment on, off, or both, at a preset time or times, after a preset interval, or cyclically. A countdown time switch switches power, usually off, after a preset time. A cyclical timer switches equipment both on and off at preset times over a period, then repeats the cycle; the period is usually 24 hours or 7 days.
There is a type of automatic timer manufactured by Kaiser, Philips, and others that by means of a photoelectric sensor (like the one in the photo or mounted inside the easel), is capable of regulating the exposure time according to the light projected by the enlarger, through the negative, on the photographic paper, magnitude inversely ...
The major advantage of a lighting control system over stand-alone lighting controls or conventional manual switching is the ability to control individual lights or groups of lights from a single user interface device. This ability to control multiple light sources from a user device allows complex lighting scenes to be created.
In 1884, Woods received his first patent, for a steam boiler furnace, [17] and in 1885, Woods patented an apparatus that was a combination of a telephone and a telegraph. The device, which he called "telegraphony", would allow a telegraph station to send voice and telegraph messages through Morse code over a single wire.
Auto-yokes" are often promoted as a way to modernize and increase the flexibility of an inventory of lighting fixtures at a reduced cost to replacement with intelligent lights. Generally, moving mirrors are faster at adjusting a lights position than moving head fixtures; however, moving-heads-style fixtures have a far larger total range of ...
Two light switches in one box. The switch on the right is a dimmer switch. The switch box is covered by a decorative plate. The first light switch employing "quick-break technology" was invented by John Henry Holmes in 1884 in the Shieldfield district of Newcastle upon Tyne. [1]