No announcement yet.

Help interpreting the multimeter...


Forum Top GA Ad Widget

  • Filter
  • Time
  • Show
Clear All
new posts

  • Help interpreting the multimeter...

    The undercabinet lights are 12v. The little transformer appears to have gone out, but I want to make sure it's not the switch before I go and drop $20 on a new transformer, or $100 on new lights (trading pucks for rope.)

    I know that I could take a wire and jump the switch (which I did - the lights stayed off, so it's the transformer, doggone it.) But I figure it's about time I learned to use this thing I inherited from my dad years ago and never used. The knowledge might be useful, given a project I've got in my head.

    FWIW, it's a Micronta 22-166A.

    Red >> 200v, black >> -COM, dial set to AC V. Circuit is ON. Across the switch with the switch open, I get a reading of ~117. With the switch closed, I get a reading of 80. How do I interpret that?


    - Bill in Kansas City, Mo, USA

    Measure with a micrometer. Mark with a crayon. Cut with an ax.
    Bill in Kansas City, MO

    Measure with a micrometer
    Mark with a crayon
    Cut with an axe.

  • #2
    digital multimeter

    your settings seem ok. verify the meter is working properly by plugging the probes into a live outlet and measuring the voltage.
    across an open switch you should read close to the line voltage. with the switch closed the reading should be close to zero.
    with the meter in the circuit, the meter and its electronics is actually completing the circuit [as if it were a switch]
    measure your voltage coming into the transformer primary, then read across the output. if step down read that voltage. you state 12 volts. any voltage reading a slight higher would be acceptable, lower, no.
    about the switch, is it only in one-half of the circuit or is it opening both sides of the line?
    everything nowadays is digital. for voltages I always trust a good ol analog meter.