Connect with us

strange timer fault

Discussion in 'Misc Electronics' started by Little Monster, Jun 4, 2004.

  1. Hi all, wonder if anyone can suggest what is going on here.

    I have a couple of electronic time switches, nice range of settings they
    have too :) They use an internal battery to keep time when the mains
    fails.

    Funny thing happened; within a month of each other (at about guarantee
    ending time), they started losing time very badly - almost an hour a day
    eventually. Unplugged them both, left them to one side, set the time
    correctly to have a look just how bad the drift was, where I could see
    them properly. Funny thing happened, they both started keeping good time
    again!

    Looking inside, the clock board has 3 ceramic caps, a crystal and chip
    epoxy bonded to the board. Small rechargeable battery feeds into it. I
    think either the ceramic caps are rated a bit too close to the battery
    voltage and leaking a bit when at charging voltage, but okay on battery
    only.. or something odd is happening with the battery or it's charging
    circuit. Not done any tests yet (not that important to fix). Guessing
    the former, I could just connect a resistor in the clock supply to take
    the voltage down a bit, but any suggestions as to what might be the cause
    of the fault - probably too subtle for me!

    Monster
    --
    I am the sexiest man in the UuuuKaaaayy
    All the girls love me
    And I will never grow Ooollldd
    I am the sexiest man in the UuuKaaaay!

    http://www.the-monstruum.co.uk
     
  2. <snip>

    Model numbers? Manufacturers? Those would be helpful.

    Cheers!

    Sir Charles W. Shults III
     
  3. Beg your pardon Sir, I thought these things were pretty generic...

    Micromark model MM9539, 230V 50Hz 13A, both have batch number 193370/0122

    Thanks for the response :)

    Monster
    --
    I am the sexiest man in the UuuuKaaaayy
    All the girls love me
    And I will never grow Ooollldd
    I am the sexiest man in the UuuKaaaay!

    http://www.the-monstruum.co.uk
     
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

-