Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Acoustic tones

  1. Mar 29, 2007 #1
    Hello. I hope you all could help me somehow. I have a pocketPC with a signal generator software. I was confused with why they only produce AC signals and no DC ones. This sounds like a basic question, but why is this? Does flat DC signals produce no sounds or is it just the software? Thanks in advance!
     
  2. jcsd
  3. Mar 29, 2007 #2
    I don't know what a DC signal would sound like, but any device that can generate a fairly complex periodic signal (Pulse, Sawtooth.......), would be able to produce a DC signal, this is because a DC signal is just a combination of sinusoidal waves (AC signal) with very close phase shifts.
    So I think it's just the software.
    btw, most function generators don't have DC output from them, first, because it's easy to get a DC source (although not an accurate variable one), second, function generators are used for testing purposes not for supplying power to your circuit and you mainly test circuits with AC.
     
  4. Mar 30, 2007 #3

    berkeman

    User Avatar

    Staff: Mentor

    If you put DC into a speaker, the cone moves to a position and stays there. So you would hear a thump when you applied the DC, and nothing after that.

    Most audio sources and speakers are AC coupled anyway, to eliminate the DC offset you generally have coming out of an amplifier stage. Maybe that's why you get nothing out when you specify a DC output from the audio signal generator.
     
  5. Apr 4, 2007 #4
    There is no reason for your pocketPC audio output to output a DC signal. DC signal doesn't work with speakers.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Acoustic tones
  1. Acoustic Modem (Replies: 31)

  2. Acoustic Modem (Replies: 6)

  3. Tone generator (Replies: 1)

Loading...