PIR to switch a 555 timer

Discussion in 'The Projects Forum' started by Speedjayg, Dec 27, 2012.

  1. Speedjayg

    Thread Starter New Member

    Dec 13, 2012
    9
    0
    Hello i am looking to hook up a PIR Sensor Module to activate a 555 timer kit that i purchased. I plan on using this PIR Sensor (http://openimpulse.com/blog/wp-cont...les/DYP-ME003_PIR_Sensor_Module_Datasheet.pdf) which outputs 3.3V on high on this kit (http://www.velleman.eu/downloads/0/illustrated/illustrated_assembly_manual_k2579.pdf) I would like to use the PIR sensor as the Switch SW1. I was wondering if that would be possible cause the PIR sensor only has a output of 3.3V or if that would work as the trigger. (The Schematics are in both links) Thanks in Advance
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,965
    744
    Use an NPN transistor like a 2n2222 , base to terminal 2 pir pcb, emitter to 0V, collector to pin 2 on the 555 timer, no base drive resistor is needed as there is one already on the pir pcb, make sure the 0v on both pcb's are connected together.
     
    Last edited: Dec 27, 2012
  3. Speedjayg

    Thread Starter New Member

    Dec 13, 2012
    9
    0
    Hello thank you for the fast reply. How would you hook those two circuits up together to get them to work properly. Can you show me how to hook these two circuits using the schematics? I plan on using the PIR sensor as Switch SW1 and then the timer will run for 8 seconds.
     
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