time delay circuit problem

Discussion in 'The Projects Forum' started by danieltuico, Feb 3, 2010.

  1. danieltuico

    Thread Starter New Member

    Jan 30, 2010
    1
    0
    hi!

    I have a project at school and it somewhat makes my head feel terrible.

    I have a Parallax PIR module set to normal mode (meaning Output goes HIGH then LOW when triggered. Continuous motion results in repeated HIGH/LOW pulses. Output is LOW when idle)

    I need two circuits that would accept the output from the PIR sensor.

    1. If the output is high it will turn on a relay for about 10 minutes. I think a 555 timer or the like would help. If within that time and the circuit is triggered again, it will reset its timer and wait for another 10 minutes. If it is no longer triggered after 10 minutes, the relay turns off.

    2. The output from the PIR sensor passes first to a "momentary push button switch circuit". If the circuit is open it ignores any output from the sensor. If the button is pushed (only once) it allows the output from the PIR to go to circuit 1. The circuit is closed for only about 15 minutes. If within that time and the circuit is triggered again with a high output, it will reset its timer and wait for another 15 minutes. If it is no longer triggered after that time, it will open the circuit.

    I found a circuit but i need second opinions if this could help me.
     
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