Looking for timed shutoff using NE555

Discussion in 'The Projects Forum' started by irozak, Apr 3, 2015.

  1. irozak

    Thread Starter New Member

    Apr 3, 2015
    3
    0
    I have a very small display box that I would like to illuminate with a couple of white led's. I want to push a button to light them up, and then they will turn off automatically after 10~30 minutes. I have a 3V power supply, and some NE555 chips, and I'm looking for a diagram that a woodworker can follow. If this is covered elsewhere please accept my apologies and point me to it. Thanks guys.
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,977
    744
    your going to struggle with 3V for a 555 timer, the leds will probably have a voltage drop of 3.4V.
     
  3. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,450
    1,066
    Biggestl problem: NE555 does not work properly at 2.5V, which is what your batteries will sag to.
     
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