Variable Delayed Astable 555 timer output

Discussion in 'The Projects Forum' started by whywhy68, Jun 11, 2008.

  1. whywhy68

    Thread Starter Member

    Jun 11, 2008
    13
    0
    instead of having a Astable output once i power up..

    is there anyway whereby i can make a delay before a Astable 555 timer output square wave is generated?
     
  2. Wendy

    Moderator

    Mar 24, 2008
    20,766
    2,536
    Yes, use another 555 to control your astable 555 oscillators pin 4.

    Conversly, you could use a resistor and a capacitor on pin 4, the resistor to Vcc, the cap to ground. The trade off is the cap has to be a large value, and the resistor a fairly small one. What kind of delay are you looking for?
     
  3. JoeJester

    AAC Fanatic!

    Apr 26, 2005
    3,373
    1,159
    You can use a power-up reset circuit. If the time isn't absolutely critical, an RC circuit will do the job.
     
Loading...