component emitting alarm audio - which is it !?!

Discussion in 'General Electronics Chat' started by denisb, Mar 19, 2013.

  1. denisb

    Thread Starter New Member

    Mar 19, 2013
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    Hi
    I have a pure sine wave inverter for my car which is emitting a high pitched low voltage alarm, even though the supplied voltage (measured at the board) is >2V higher (12.6V) than the trigger voltage (10.5V). This happens whenever the car's engine is turned off. The unit continues to deliver adequate 240V to plugged appliances.

    I would like to simply kill the component emitting the alarm audio, but don't know what it looks like.

    Can anyone help me identify it?

    Can I do this but keep the circuit board functional?

    thanks
    denis
     
  2. Dodgydave

    Distinguished Member

    Jun 22, 2012
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    it will be a piezo buzzer , round device about 1inch diameter with a hole in .
     
  3. denisb

    Thread Starter New Member

    Mar 19, 2013
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    any suggestions how i might disable the component without damaging the rest of the circuit?
     
  4. spinnaker

    AAC Fanatic!

    Oct 29, 2009
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  5. MrChips

    Moderator

    Oct 2, 2009
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    It's ok. This is an inverter that is plugged into the 12V accessories outlet and is not part of the vehicle. My inverter does the same thing too. You can disconnect the buzzer by simply cutting one of the wires to the buzzer.
     
  6. denisb

    Thread Starter New Member

    Mar 19, 2013
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    err, yes. thanks for pointing that out. this is not part of a car, it is a stand-alone inverter which happens to draw its power from a car battery, independently of the car's ignition circuit.
     
  7. denisb

    Thread Starter New Member

    Mar 19, 2013
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    is this it?
     
  8. MrChips

    Moderator

    Oct 2, 2009
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    Yep. That's it.
    If you tape over the hole it will muffle the sound quite a bit.
     
  9. denisb

    Thread Starter New Member

    Mar 19, 2013
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    i stuck some epoxy putty and the hole. but now i've discovered that there's a protection circuit that kicks in some time later which turns the unit off.
    disabling that is somewhat beyond my skill level :(
     
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