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Seeking switch debouncing circuit

Discussion in 'Hobby Electronics' started by Charles L, Nov 14, 2003.

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  1. Charles L

    Charles L Guest

    Can someone suggest or point me to a simple switch debouncing circuit for a
    Single Pole Double Throw Switch using an S-R latch? I am quite new to this
    and haven't been able to find a circuit anywhere.

    Thanks in advance.

    Charles L
  2. a small value cap over the switch contacts aparently works
  3. Ken Taylor

    Ken Taylor Guest

    The common of the switch goes to ground (or pulled to Vcc, depending on the
    requirements of the S-R latch). The contacts then go to the Set and Reset
    inputs. The 'switch' output is then the output of the latch, either the Q or
    /Q, depending on what you want. Tie the Set and Reset to the appropriate
    rail so that they don't float to the 'switch' condition.

    With this, when you switch to one side, you will Set the latch, and it
    doesn't matter if it bounces, the output remains stable. Ditto when you
    switch the other way.

  4. KLR

    KLR Guest

    Tried that many years ago. It doesnt.

    I recall using a 555 in one-shot mode to solve this problem at the
  5. bruce varley

    bruce varley Guest

    A common an effective aproach is to connect 2 2-input nand gates as a RS
    flipflop, which is maybe what you're thinking of.....

    OP1 -> IP2a
    OP2 -> IP1a

    IP1b, IP2b both have a pullup to Vcc (about 4K7), and each goes to one side
    of the SPDT switch. The common of the switch goes to ground.
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