LED Strip activation via PIR

Discussion in 'The Projects Forum' started by BluFox, Nov 23, 2015.

  1. BluFox

    Thread Starter New Member

    Nov 23, 2015
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    Good evening everyone,

    My name is Brandon. Although this is my first time posting here on the forum, I have been around and very much enjoy reading what you guys are working on and what you all have to teach. I am very interested in electronics, however the path I chose was a degree in law followed by a law practice. Obviously this is on the extreme opposite side of the spectrum of anything that deals with electrical components. That being said I have a project that I am very interested in starting. I want to run an LED strip under my bathroom counter that is activated via a PIR motion sensor. Upon days of research I have acquired, what I believe is all essential items/components required for this project. However outside of purchasing these items and researching on the basic functionality of each I am absolutely STUCK at what to do at this point.

    My current inventory is as follows. (Each item is linked to an in depth webpage)
    What would you "engineers" recommend me do at this point or study at this point being as I have no idea where to start or how to wire these items. All information that any of you are willing to pass my way will be greatly appreciated!

    P.S - I hope I have provided you all with enough information to adequately help.
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,003
    745
    Ok, all you need is the led strip, psu, pir timer with mosfet or relay output.

    I take it you want the leds to come on when it detects a person in the room, and then time out after a period of minutes?
     
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  3. BluFox

    Thread Starter New Member

    Nov 23, 2015
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    Exactly Dave! But I do not understand what process the mosfet serves? or what gets wired to what.
     
  4. Bernard

    AAC Fanatic!

    Aug 7, 2008
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    How many feet of strip to be used. Best guess that I can figure is each meter needs 5W, 5 m = 25W , power supply 36W - seems a good match. PIR output assuming 3.3V output on movement drives logic level FET gate. Strip positive to +12V, neg. to drain, source to ground(-)..
     
  5. RRITESH KAKKAR

    Senior Member

    Jun 29, 2010
    2,831
    89
    You mean how to use mosfet or BJT? to Drive leds from it?
     
  6. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    745
  7. BluFox

    Thread Starter New Member

    Nov 23, 2015
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    The length is 63 inches, and the PIR I purchased has a timer built in. I'm just not sure how to wire th project from the PSU to the PIR, MOSFET, LED STRIP.
     
  8. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,003
    745
    Connect the output of the pir to the Gate of the fet, Source to 0V, and leds to Drain and +12V

    like this .... pir.png

    when the pir detects you , the output goes high to 3V , switches the fet on via an internal 1K resistor, and puts the leds on.
     
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