Car door open alert

Discussion in 'The Projects Forum' started by vivc, May 27, 2013.

  1. vivc

    Thread Starter New Member

    May 27, 2013
    2
    0
    So I'm busy building a simulator for car, which would be perfect with car "open door" alert sound. Here's what I mean- http://www.youtube.com/watch?v=3-IUtkSNtmA
    Now the question is, can such a sound be produced using a 555? Schematics anyone?
    Thanks!!!
     
  2. tracecom

    AAC Fanatic!

    Apr 16, 2010
    3,871
    1,394
    I think that sound is too complex to be produced by a 555. You will likely need a real audio file (such as an MP3 file) put on one of those audio greeting card chips.
     
  3. LDC3

    Active Member

    Apr 27, 2013
    920
    160
    You might get something close with a 555 timer since it is just one pitch, but I think it is a combination of tones, which would need more 555s. Also, you need a sawtooth generator to control the volume (which needs another 555).
     
  4. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
  5. LDC3

    Active Member

    Apr 27, 2013
    920
    160
    Here is the schematic I came up with which you will need to do some adjustments to for the right tone. The 556 timer is used to produced 2 tones which you can vary by changing R2 and R4. I just realized that C5 should be 1 μF and not 0.1 pF. R6 will vary the length of time the volume decreases over. R8 and R9 should be the same as R2 and R4. This will change the square wave to a sawtooth wave with nearly equal rise and fall times. R10 will control the volume as well as the feedback amplification of R15 and R16.
     
    vivc likes this.
  6. vivc

    Thread Starter New Member

    May 27, 2013
    2
    0
    This looks interesting. I'll give it a try & let you know!

    Cheers!
     
Loading...