Speaker or Piezo?

Discussion in 'The Projects Forum' started by Smijo, Nov 27, 2012.

  1. Smijo

    Thread Starter New Member

    Nov 15, 2012
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    0
    I have part of a circuit where I'm not sure if I'm supposed to use a piezo or a regular speaker. I have uploaded part of my schematic from Eagle, and also the circuit I based it on from a URL. Should I use a piezo or a speaker? I tried a piezo today, and it only clicked.
     
  2. Audioguru

    New Member

    Dec 20, 2007
    9,411
    896
    In Siren 1 you connected pin 4 to pin 2 and pin 6 which is wrong.
    In Siren 2 you connected pin 3 to pin 2 and pin 6 which is also wrong.

    A speaker in a proper enclosure will sound like a siren. A piezo will make a high pitched little squeak.
     
  3. Dodgydave

    Distinguished Member

    Jun 22, 2012
    4,967
    744
    Yep your circuit is wrong, the yellow circuit is correct..
     
  4. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
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    I redrew the schematic for a 556 but it's too much hassle to upload since the attachment manager won't work with android.
     
  5. Smijo

    Thread Starter New Member

    Nov 15, 2012
    26
    0
    I know the yellow circuit is correct, but should I use a piezo or like an 8ohm speaker?
     
  6. bertus

    Administrator

    Apr 5, 2008
    15,638
    2,344
    Hello,

    Piezo's will only be good for very high pitch tones.
    An 8 Ohm speaker will work, but only at a low volume level.
    An 32 or 150 Ohms speaker will be better for the 555.

    Bertus
     
    shreeram likes this.
  7. shreeram

    New Member

    Nov 29, 2012
    29
    1
    Yes ...right
     
  8. tubeguy

    Well-Known Member

    Nov 3, 2012
    1,157
    197
    If you can't find a higher impedance speaker you could wire a number of small 8 or 16 ohm speakers in series.
     
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