Conversion touching keys to a press keys

Discussion in 'General Electronics Chat' started by sendbad, Jan 8, 2015.

  1. sendbad

    Thread Starter Member

    Jan 8, 2015
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    1
    Hello
    I have a control panel with touch keys
    Does any one has idea to turn the keys to a press key
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    Maybe a clearer description of what you have and what you want.
     
  3. sendbad

    Thread Starter Member

    Jan 8, 2015
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    1
    ok gopher

    i have acontrol board of motor
    with keys work by toch Which are powered by electricity charg issued by the body
    i want to turn thes keys to work with press which make contact for tow point
     
  4. sirch2

    Well-Known Member

    Jan 21, 2013
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    I suspect what GopherT had in mind was something more than saying the same thing with a few more words. What is the make/model of the equipment, do you have a circuit diagram, post pictures of the device, the circuit board, the touch panel connector and write a detailed description of the requirements that is much longer than three lines...
     
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  5. sendbad

    Thread Starter Member

    Jan 8, 2015
    43
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    i Will attach an image
    Clearly the problem
    Is that the key touch has a single point of contact in the board
    Does anyone has an idea about the work of these keys
     
  6. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    Do these keys move (even a little) or are they fixed?

    If they move then they are mechanical switches. Just about anything can read that.

    If they do not move they are capacitive switches and need a circuit that can sense the change in capacitance when your finger is on it.
     
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  7. sendbad

    Thread Starter Member

    Jan 8, 2015
    43
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    thank you erniem
    I think you understand what I mean
    thes keys not move they are capacitive switches , has a single point of contact with ic that sense the change in capacitance when finger is on it
    can i turn it to press switches whech make contact of tow point
     
  8. Alec_t

    AAC Fanatic!

    Sep 17, 2013
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    What is a "tow point"?
     
  9. Brevor

    Active Member

    Apr 9, 2011
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    I think he means " makes contact between two points"
     
  10. #12

    Expert

    Nov 30, 2010
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  11. sendbad

    Thread Starter Member

    Jan 8, 2015
    43
    1
    yes thats true
     
  12. sendbad

    Thread Starter Member

    Jan 8, 2015
    43
    1
  13. ErnieM

    AAC Fanatic!

    Apr 24, 2011
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    I am not sure what the photos show. Sorry, they are not clear enough.

    Are those springs?
     
  14. djsfantasi

    AAC Fanatic!

    Apr 11, 2010
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    I agree with @ErnieM

    Are you sure there are two contacts? Perhaps one or two soldered joints are mechanical for the spring.

    However, even if there are, one can get a pushbutton with matching multiple contacts. Like this one (look through the datasheet) which is a SPDT pushbutton.
    http://sensing.honeywell.com/index.php?ci_id=142077
     
  15. wayneh

    Expert

    Sep 9, 2010
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    Those are capacitive sensor switches. The springs hold them securely to the back of the control panel without having to worry about precise alignment and fasteners.

    I believe, but could be wrong, that you could replace them with pushbuttons as #12 showed. That's exactly what I did with my kitchen stove after the touchpad switches failed. Those were resistance pads. I simply drilled a hole in each switch pad on the control panel, installed a pushbutton, and routed wires to the control board, replacing the ribbon cable that had also failed.
     
  16. cmartinez

    AAC Fanatic!

    Jan 17, 2007
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    Yes, they are capacitive sensor switches, I recognize them because I worked with them a few years ago. I'm almost sure they cannot be replaced with normal circuit-closing push buttons, since each spring acts as a sensing element NOT based on open or closed circuit logic.
     
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  17. sendbad

    Thread Starter Member

    Jan 8, 2015
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    1
    thes capacitive sensor switches
     
  18. sendbad

    Thread Starter Member

    Jan 8, 2015
    43
    1
    j
    ast one contact point for evry switch
     
  19. sendbad

    Thread Starter Member

    Jan 8, 2015
    43
    1
    ic control work with capacity not on- off switch
     
  20. sendbad

    Thread Starter Member

    Jan 8, 2015
    43
    1
    yes cmartnez
    You diagnosed the problem completely
    i hop find idea
    to solve it
     
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