Looking for help on a simple push-button delay design

Discussion in 'General Electronics Chat' started by JerryH, Jan 10, 2011.

  1. JerryH

    Thread Starter New Member

    Jan 10, 2011
    Hello all, I'm new to this site so I hope I posted into the correct forum.

    I've been trying to locate a sample design that would allow me the following function: Push a button and immediately send an "on" pulse...if I continue to hold down the button for another full second, start sending pulses at about 2/3 times per second until I release the button.

    This kind of functionality is common on appliances, such as holding the Up/Down Channel buttons on a TV remote, or to quickly set a digital clock.

    I get the feeling the ubiquitous 555 would be used in this scenario, but I've just too many gaps in my knowledge. Thank you!
  2. #12


    Nov 30, 2010
    More than one 555 (also known as a 556). Let the pushbutton send the first pulse (capacitively coupled) while starting "Timer one", a 555 configured as a one-shot. When timer 1 clocks out in one second, it allows a second 555 to start oscillating at 2/3 Hz.

    Meanwhile, the button did an enable function, so when the button is released, everything stops.

    That's a block diagram. The schematic comes next.
  3. KMoffett

    AAC Fanatic!

    Dec 19, 2007