Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Help with manipulating a digital signal

  1. Sep 8, 2007 #1
    Hi everyone, software engineer here that needs help with a basic EE project for an automotive application.

    I have a digital hall sensor that goes high (+2v) once per engine revolution. This high signal is used to time the ignition spark, and its frequency is used to determine the engine RPM.

    Here is the challenge: I need to slightly delay this signal using discrete components, without significantly altering the amplitude or frequency. I want to basically shift the entire curve back a millisecond or two or twenty (TBD).

    If this isn't possible with discrete components, I need the simplest IC solution.

    Any clues would be much appreciated!!!


    Last edited: Sep 8, 2007
  2. jcsd
  3. Sep 9, 2007 #2


    User Avatar
    Gold Member

    Welcome to PF, Terry.
    I really know nothing about electronics in general, and certainly nothing about this specifc application. I'm wondering, though, if you couldn't just use the same system (whatever it is) that bands use for the 'echo' effect. It's pretty much just a matter of capturing the signal, storing it, and then releasing it. Wouldn't a capacitor setup do that? Or maybe a basic memory chip?
  4. Sep 9, 2007 #3
    The problem with a capacitor is that I would lose the square properties of the signal, which I need to preserve. Good idea though, I was thinking a capacitor that triggered an op-amp to rebuild the square signal could work, but I am hoping there is an easier way.
    Last edited: Sep 9, 2007
  5. Sep 9, 2007 #4


    User Avatar
    Science Advisor
    Gold Member

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook