What Switch Configuration is This?

Discussion in 'General Electronics Chat' started by nDever, Apr 28, 2012.

  1. nDever

    Thread Starter Active Member

    Jan 13, 2011
    154
    4
    Hey,

    This is the PCB inside of a NES controller. When the player presses a button, the pad connected to the underside of the button comes in contact with the circular pad on the PCB which completes the circuit for that particular button.

    Are these some type of membrane switches? Does anyone know the name of these types of switches?

    [​IMG]
     
    Last edited: Apr 28, 2012
  2. #12

    Expert

    Nov 30, 2010
    16,310
    6,817
    Single pole, single throw, normally open.
     
  3. nDever

    Thread Starter Active Member

    Jan 13, 2011
    154
    4
    I'm sorry. I meant for the title to be "What Type of Switches are These?".
     
  4. #12

    Expert

    Nov 30, 2010
    16,310
    6,817
    I can't remember. I can say they are based on conductive carbon that has significant resistance, but sufficient conduction for the circuit they are used in.

    Anybody else know the answer?
     
  5. paulktreg

    Distinguished Member

    Jun 2, 2008
    612
    120
  6. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    Some people call them chiclet switches but "conductive rubber switch" and "conductive rubber keypad" are common industry terms.
     
  7. nDever

    Thread Starter Active Member

    Jan 13, 2011
    154
    4
    It seems that they would eliminate contact bounce because the contact is caused by direct human input, that is, there is nothing that would bounce...

    Does this seem reasonable?
     
  8. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    No. Your implication that only a switch with a sprung contact indirectly tied to the mechanical actuating force can bounce is incorrect. Even a soft contact material held open by nothing but gravity in an inverted configuration will exhibit some bounce. Membrane switches don't bounce as much as switches with springy metal contacts but they still bounce.

    http://www.maxim-ic.com/app-notes/index.mvp/id/287
     
    nDever likes this.
  9. mozikluv

    AAC Fanatic!

    Jan 22, 2004
    1,437
    1
    hi,

    very informative reference on switch bounce :D. i agree with your comment. that's why switch debouncing is still needed.

    mozikluv
     
  10. nDever

    Thread Starter Active Member

    Jan 13, 2011
    154
    4
    Does anyone know how I could get these types of switches implemented on a PCB?
     
  11. KJ6EAD

    Senior Member

    Apr 30, 2011
    1,425
    363
    Since most are custom designed into your product, the manufacturers have design guides.
     
Loading...