A challange to all electronic experts (and hobbists)

Discussion in 'General Electronics Chat' started by myvbox, May 26, 2010.

  1. myvbox

    Thread Starter New Member

    May 26, 2010
    Hi everyone,

    I'm trying to put up a fairly simple electronic system and I need your help.
    The helper will get rewarded $$$ !! [​IMG]
    here we go...

    The system components:

    * 1 large illuminated red button
    * Timer relay
    * Red LED countdown timer (2 digits)


    1) The button should be connected to a monitor (normal PC 17'' monitor)
    and to the countdown timer
    2) Each time the button is pushed the timer should countdown 30 seconds, and the monitor will switch on for that period only (30 secs)
    3)after 30 seconds the monitor will switch off, (the timer can show 00 or 30 - waiting for the next push (to countdown again)

    Thank you for you time [​IMG]




    This is not some homework or an assignment - it is a small part of a bigger system that I have built - for my personal use.
  2. SgtWookie


    Jul 17, 2007
    A PIC12Fx or PIC16Fx uC controlling an analog switch to turn off the monitor video, and supplying the multiplexing for a dual 7=segment display with a comparator looking for a change in the input from the button.

    What are you offering?
  3. retched

    AAC Fanatic!

    Dec 5, 2009
    Sounds like a game show type control.

    When the button is pressed an image will appear for 30 seconds then blank and wait for the next press.

    The Sarge needs a new pair of shoes. (Wookies wreak havoc on shoes) ;)
  4. John P

    AAC Fanatic!

    Oct 14, 2008
    Nah. An LM555 timer for the timebase, a couple of chips to do the counting and turn the counters off when done, 7-segment decoders, and a relay to do whatever gets done to the monitor.

    By the way, you haven't specified what happens if the user presses the button again during the count. Does it give a renewed 30 seconds, or is it locked out until the countdown ends?
  5. retched

    AAC Fanatic!

    Dec 5, 2009
    You could make a 1 key, PC keyboard, then do all the video and counting on the PC.

    That would allow for easy video swapping and such, as well as score counting, audio prompts, and access to All About Circuits during down time. ;)