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Saturday, 16 April 2011

Bounceless Switch


1 comment:

  1. as i see it there's a problem with the node connecting to switch.L and iC.5 -- namely the mechanical metallic conductor switch has contact resistance of 0.1 to 200 Ω -- so the 100k from CMOS ~1kΩ out put won't cancel a strobe as such ...

    the contact strobe is a switch dependent mechanical vibration that may vary by peak frequency from 100-s of kHz to few kHz and the strobe burst may be recurrent fading as :
    ____··l·!l!!·!''·!l'·!''!l'''¯''¯¯'¯¯¯
    — lasting up to several milliseconds

    . . .

    so - a speculative way to overcome such - not modifying the shown circuit too much - is to place a diode as P to OUTP , N to INP in series with each of the 100kΩ resistor and a resistor from GND to Switch common up to 100kΩ value . . . then take output signal from eighter iC pin 2 or 4 through additional amplifying inverter or 2 or 3 - to get/shape the sharp transition edge for digital inputs . . .

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