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What will trigger a capacitance touch sensor?

  1. May 18, 2009 #1
    I've got an iPod Touch and am trying to create an electrical circuit that, when turned on, will trigger the touch sensor in a specific spot (the spot that whatever component of the circuit provides capacitance is resting on, I guess).

    For the life of me, I cannot figure out how to trigger a capacitance sensor. I know what it needs; capacitance. Human fingers provide that. I've discovered that the negative side of a battery also works; but how can I control it?
     
  2. jcsd
  3. May 18, 2009 #2

    berkeman

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    Staff: Mentor

    You can put an array of small metal squares over the spots, and use transistors to connect one square at a time to ground. The others will have some capacitance to ground, but much less than when the transistor is turned on.
     
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