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On sound(Sensors)

  1. Aug 5, 2004 #1
    On sound

    Hi everyone... how does a sound controlled sensor work, like those in the toys?
     
  2. jcsd
  3. Aug 5, 2004 #2
    I am guessing......If you think about how the sound propagates, we know the sound is a form of wave that travels through the medium such as air. So when the sound is created there must be some disturbance in the air which can be sensiable mechanically by well designed detector. Imagine you're in the water. If disturbe the water by swinging my hand under the water next to you won't you feel the disturbance? I think that will triggers the what ever the action the toy will take
     
  4. Aug 5, 2004 #3

    Claude Bile

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    The receiver on a phone, for instance is a transducer which converts air pressure signals (i.e. sound) into electric signals. When a sound wave impinges on the transducer, it converts it into an electrical signal, which is then used to set of whatever it is supposed to set off.

    Claude.
     
  5. Aug 6, 2004 #4
    I doubt a toy would have a sound sencor as complicated on a phone.
     
  6. Aug 7, 2004 #5
    What kind of toy? Are we speaking of a common microphone? Like a sound wave can move an eardrum, it can move a magnet, and moving a magnet besides a wire will generate a current in the wire. That's a mike.

    Now if the wire is 1 km long, you almost got a telephone.

    Put another magnet attached to a membrane on the other end of the wire, and its current will make the magnet-membrane do the same airwaves that originally made the current. That's a speaker, and completes the telephone. That's the concept.
     
  7. Aug 7, 2004 #6
    I disagree. Go to Radio Shack and by a small condensor mic for a couple of dollars. Same deal.
     
  8. Aug 8, 2004 #7
    A sound sensor in a toy does not have to be as accurate as a phone which must replicate the human voice quite accurately for it to be understood and to identify a person. Some sensors may be quite sensitive to particular sound frequencies and not to others, especially ones using acoustically active materials such as quartz.
    Sensors are usually desribed by their sensitivity and spectral/spacial response which vary considerably depending on their size and construction.
    Ray
     
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