Timed Temporary Grounding Circuit

Discussion in 'The Projects Forum' started by calkirley, Feb 7, 2013.

  1. calkirley

    Thread Starter New Member

    Oct 2, 2011
    Hi everyone.

    I need your help with a project. I have a basic idea of the components involved, but I am stuck on how to do a certain step.

    The circuit that I am designing must have three functions;
    1) When a button is pressed, the circuit must ground another circuit.
    2) After grounding circuit 2 for a certain amount of time, circuit one shuts down and allows circuit 2 to start again.
    3) Circuit 1 repeats only once when a trigger button is pushed.

    I knew that I would have to use a 555 timer to control the timing function of the circuit and a transistor to control the grounding function, but what I have no idea how to do is to make the timer only cycle high once.

    Sorry if this is a ridiculously easy question for most, but I'm currently taking a class called Project Lead the Way: Digital Electronics and I'm trying to learn all that I can. My knowledge is pretty limited so far; all we have covered in this class is breadboarding simple circuits, 555 timers, adders, and other simple, basic functions.

    Thanks for reading,

  2. #12


    Nov 30, 2010
    Don't connect the discharge pin to the timing network and have the "start" button force a reset.