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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.
Nūr (Arabic: النور) is a term in Islamic context referring to the "cold light of the night" or "heatless light" i.e. the light of the moon. This light is used as a symbol for "God's guidance" and "knowledge", a symbol of mercy in contrast to Nar, which refers to the diurnal solar "hot light" i.e. fire. [1] In the Quran, God is stated to be "the light (Nūr) of the heavens and the earth ...
A nightlight is a small light fixture, usually electrical, placed for comfort or convenience in dark areas or areas that may become dark at certain times, such as at night or during an emergency. Small long-burning candles serving a similar function are referred to as "tealights".
Moving lights are much more difficult to program than their conventional cousins because they have more attributes per fixture that must be controlled. A simple conventional lighting fixture uses only one channel of control per unit: intensity. Everything else that the light must do is pre-set by human hands (colour, position, focus, etc.)
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.
An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the "bulb" to the ...
Starlight overcast moonless night sky [1] 140 microlux: Venus at brightest [1] 200 microlux: Starlight clear moonless night sky excluding airglow [1] 10 −3: 1 millilux: 2 millilux: Starlight clear moonless night sky including airglow [1] 10 −2: 1 centilux: 1 centilux: Quarter Moon 10 −1: 1 decilux: 2.5 decilux: Full Moon on a clear night ...
A junction for road vehicles and pedestrians controlled by traffic lights in the UK. The various vehicle and pedestrian movements are separated in either time or space for safety and efficiency. The normal function of traffic lights requires more than sight control and coordination to ensure that traffic and pedestrians move as smoothly, and ...