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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]
Dimmer light switch with RF-based remote control [1] A wireless light switch is a light switch that commands a light or home appliance to turn itself off or on, instead of interrupting the power line going to the light fixture. There are different ways to communicate between the switch and the fixture: [2]
The purpose of bias lighting is to reduce the perceived brightness of the display as a result of the contrast with the slightly illuminated area around it. [1] This reduces the eye strain and fatigue that occurs when viewing a bright display against a very dark background for an extended time, [1] and increases the perceived blackness, perceived highlights, and overall contrast of the display.
[11] [12] It was sold as a night-light from 1997 to 2005 by the Archie McPhee company, [13] reminiscent of the times when a fairly common late-night experience was to fall asleep while watching the late movie, only to awaken to the characteristic sine wave tone accompanying the Indian-head test pattern on a black-and-white TV screen.
An ELP gives off uniform light over its entire surface, but other backlights frequently employ a diffuser to provide even lighting from an uneven source. Backlights come in many colors. Monochrome LCDs typically have yellow , green , blue , or white backlights, while color displays use white backlights that cover most of the color spectrum .
Burn-in on a monitor, when severe as in this "please wait" message, is visible even when the monitor is switched off. Screen burn-in, image burn-in, ghost image, or shadow image, is a permanent discoloration of areas on an electronic visual display such as a cathode-ray tube (CRT) in an older computer monitor or television set.
The time switch can be programmed to turn on or off a connected device at specific times or according to a set schedule. For example, a user could program the time switch to turn on the lights at a certain time in the morning and turn them off at night, or to activate a heating system at a specific time before the user arrives home from work.
In the late 1940s, Zenith entered the television market. These sets were all-round tube sets. The main feature was that the entire round screen was exposed. They were available in 12-inch, 16-inch and 19-inch sizes. Later round-tube models had a switch that would show the picture in the 4:3 ratio, or have the entire round screen exposed.