Monostable IC 555 Circuit

Discussion in 'The Projects Forum' started by vick5821, Jan 29, 2012.

  1. vick5821

    Thread Starter Member

    Jan 27, 2012
    54
    0
    Hey friends, recently I have built a 555 monostable circuit.It works fine.However, the circuit will lights up if I shake the circuit and off after some period of time.I didnt press the trigger button.

    Anyone knows what happened ?

    The connection I think is ok since it works.

    Thank you
    [​IMG]
     
  2. PaulEE

    Member

    Dec 23, 2011
    423
    32
    Do you have all capacitors in place? Power supply bypass? Is the timer snug in it's socket? Are you triggering it by touching any of the exposed conductors?

    Just some thoughts.
     
  3. vick5821

    Thread Starter Member

    Jan 27, 2012
    54
    0
    Oh yes..I forgot to put the capacitor when took this picture.I will put them in the female header socket..Yes, it will being triggered if I touch the back side of the donut board
     
  4. sheldons

    Active Member

    Oct 26, 2011
    616
    101
    where is your timing capacitor?post your schematic ?
     
  5. vick5821

    Thread Starter Member

    Jan 27, 2012
    54
    0
    My timing capacitor is connected between the trigger, threshold pin and ground pin..will post the schematic soon :)

    [​IMG]
     
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