enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Passive infrared sensor - Wikipedia

    en.wikipedia.org/wiki/Passive_infrared_sensor

    PIR sensors are commonly used in security alarms and automatic lighting applications. PIR sensors detect general movement, but do not give information on who or what moved. For that purpose, an imaging IR sensor is required. PIR sensors are commonly called simply "PIR", or sometimes "PID", for "passive infrared detector".

  3. Wireless powerline sensor - Wikipedia

    en.wikipedia.org/wiki/Wireless_powerline_sensor

    Wireless overhead power line sensors hanging from each of the three phases of a 4160 Volt powerline in a residential neighborhood, in Palo Alto, California. A Wireless powerline sensor hangs from an overhead power line and sends measurements to a data collection system.

  4. 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.

  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. 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 ...

  7. 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]

  8. Electrical wiring - Wikipedia

    en.wikipedia.org/wiki/Electrical_wiring

    A form of bus duct known as "plug-in bus" is used to distribute power down the length of a building; it is constructed to allow tap-off switches or motor controllers to be installed at designated places along the bus. The big advantage of this scheme is the ability to remove or add a branch circuit without removing voltage from the whole duct.

  9. 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.