AC mains fault indicator

Discussion in 'General Electronics Chat' started by gotumal, May 13, 2008.

  1. gotumal

    Thread Starter Active Member

    Mar 24, 2008

    Recenly I saw a AC mains extension box with fault indicator. It was having different LED indications for many conditions like "line broken", "line-neutral reversed", "earth broken" etc.
    The interesting part was that it was selling for 0.5$. I really wonder what was there inside which can be sold at this rate including, material & fabrication cost, commision etc.

    I could imagine such circuit with some comparators, discretes. Does anybody have a circuit with minimum no. of components?
  2. KMoffett

    AAC Fanatic!

    Dec 19, 2007
    From all the ones I've seen, there are only three neon lamps with series resistors between L-N, L-G and N-G. The case/plug is the most expensive part. It will not detect a N-G reverse. :(