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  2. Security alarm - Wikipedia

    en.wikipedia.org/wiki/Security_alarm

    PIR sensors identify abrupt changes in temperature at a given point. As an intruder walks in front of the sensor, the temperature at that point will rise from room temperature to body temperature and then back again. This quick change triggers the detection. PIR sensors designed to be wall- or ceiling-mounted come in various fields of view ...

  3. Occupancy sensor - Wikipedia

    en.wikipedia.org/wiki/Occupancy_sensor

    Occupancy sensor types include: PIR sensors, which work on heat difference detection, measuring infrared radiation.Inside the device is a pyroelectric sensor which can detect the sudden presence of objects (such as humans) who radiate a temperature different from the temperature of the background, such as the room temperature of a wall.

  4. Passive infrared sensor - Wikipedia

    en.wikipedia.org/wiki/Passive_infrared_sensor

    The PIR sensor is typically mounted on a printed circuit board containing the necessary electronics required to interpret the signals from the sensor itself. The complete assembly is usually contained within a housing, mounted in a location where the sensor can cover the area to be monitored.

  5. Motion detector - Wikipedia

    en.wikipedia.org/wiki/Motion_detector

    A passive infrared detector mounted on circuit board (right), along with photoresistive detector for visible light (left). This is the type most commonly encountered in household motion sensing devices and is designed to turn on a light only when motion is detected and when the surrounding environment is sufficiently dark.

  6. Wireless light switch - Wikipedia

    en.wikipedia.org/wiki/Wireless_light_switch

    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]

  7. Digital Addressable Lighting Interface - Wikipedia

    en.wikipedia.org/wiki/Digital_Addressable...

    Digital Addressable Lighting Interface (DALI) is a trademark for network-based products that control lighting.The underlying technology was established by a consortium of lighting equipment manufacturers as a successor for 1-10 V/ 0–10 V lighting control systems, and as an open standard alternative to several proprietary protocols.

  8. 19-inch rack - Wikipedia

    en.wikipedia.org/wiki/19-inch_rack

    The height of a rack can vary from a few inches, such as in a broadcast console, to a floor-mounted rack whose interior is 45 rack units (200.2 centimetres or 78.82 inches) high. 42U is a common configuration. Many wall-mounted enclosures for industrial equipment use 19-inch racks.

  9. Solid-state relay - Wikipedia

    en.wikipedia.org/wiki/Solid-state_relay

    A solid state relay (SSR) is an electronic switching device that switches on or off when an external voltage (AC or DC) is applied across its control terminals. They serve the same function as an electromechanical relay , but solid-state electronics contain no moving parts and have a longer operational lifetime.