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Motion sensor

  1. Mar 8, 2012 #1
    Dear Experts

    I come across a website showing specifications of a PIR motion sensor for toilets.

    I quote the specs :

    Type 180° Motion Sensor
    Application Toilet, WC, Bathrooms, Restroom, Cloakroom
    Technology Wall mount Passive Infrared PIR motion sensor
    Reach 10 meters
    Time Setting 5 Sec - 15 Minutes
    Lux setting facility 2-2000 Lux
    Load switching 500 Watts Inductive - 230V AC

    I cannot believe it!

    A motion sensor consumes 500watts ?

    Is this typical for say a normal office toilet?

    For instance, a PIR motion sensor used to save toilet lighting throughout the day.

    So, I just like to know how much electricity typically such a sensor consumes and is the above specs typical?

    Thanks very much .

    Have a nice day.

    Best regards
  2. jcsd
  3. Mar 8, 2012 #2


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    Science Advisor

    No, the sensor itself only consumes less than a few watts, but it can switch lights which consume up to 500 watts.

    I have a motion sensor that switches a pair of 150 watt lamps when it detects motion and provided it is not in daylight.
    The lamps go out after 30 seconds or so.

    So, yes, yours is probably pretty typical.
  4. Mar 8, 2012 #3


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    Staff: Mentor

    I'm surprised that the specs don't indicate standby power usage. That could be a selling point where other specs are typical.
  5. Mar 8, 2012 #4
    Maybe they themselves do not know either.
  6. Mar 17, 2012 #5
    Hi Everyone,

    Thanks for your comments.

    Does anyone know how much standby power is consumed ? For example, 1% out of total usage?

  7. Mar 17, 2012 #6


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    Science Advisor

    Here is a motion sensor module:


    As you can see, it runs off 5 volts DC and draws less than 100 μA.

    If one of these was used in a mains powered device, there would be losses in developing 5 volts DC but the motion sensor itself would not draw much power.

    This power would be constant, though. 24 hours a day.
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