Connect with us

Lightning Detector.

Discussion in 'General Electronics Discussion' started by cjdelphi, Apr 6, 2012.

Scroll to continue with content
  1. cjdelphi


    Oct 26, 2011
    I came across this Circuit...


    I don't really understand the role of the 555, the 555 is set to monostable/1 shot, when current is inducted to the 4ft long copper wire, the voltage/current goes through this circuit, but why would you use the 555 trigger pin for a single pulse? why not simply have the transistor feed straight into the optocoupler?...

    i'm missing something here, I'd love to one day build a lightning detector but knowing me i'd probably want to get as close to a storm as possible a few times just to make sure it works lol... anyway what's the role of the 555 in this circuit?
  2. Harald Kapp

    Harald Kapp Moderator Moderator

    Nov 17, 2011
  3. cjdelphi


    Oct 26, 2011
    The time is too short for the arduino and not 555?
  4. BitHead


    Mar 2, 2012
    Yes - the 555 looks like it's going to generate a nice, long 1/2 sec.-ish pulse when it's triggered by what could be the very short-duration (sub-microsecond) spiky tip of a lightning strike detect. That's this monostable's job - taking bouncy, spiky, weak transient 'low-going' voltages and turning them into predictably clean-edged, long-duration ones. The monostable is also used a lot for de-bouncing push-button switches being pressed by hesitant, lightly pushing fingers so quick-responding uControllers don't do something twice - or ten - times.
  5. (*steve*)

    (*steve*) ¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd Moderator

    Jan 21, 2010
    Also it will essentially integrate pulses over half a second. This means that many pulses generated from the strike get counted only once.

    edit: integrate is the wrong word
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day