SPST bounce non realistic simulation in Proteus ISIS

Discussion in 'The Projects Forum' started by ilnar, May 24, 2012.

  1. ilnar

    Thread Starter New Member

    May 8, 2012
    16
    0
    ok here is my question. any button press in real time would stimulate hundreds of impulses (bounces) before button finally touches the surface of it's buttom terminal right? since we humans are not nano speeded creatures we take many milliseconds to press the button and during these milliseconds circuit closes and brakes many times. thats why bounce suppressor circuit was invented; to get rid of the bounces. i am trying to simulate these conditions. but in proteus my SPST doesnt generates these bounces at all. while pressing, it instantaneously closes the circuit and bounces are not generated. tried to set bigger switching time in parameters, didn't worked either. what can i do ? i'v tried switch, SPST, both turn on without bouncing... :( LT Spice doesnt have interactive simulation at all. i mean i cant click anything while simulating there.
     
  2. absf

    Senior Member

    Dec 29, 2010
    1,493
    372
    A simulator is a simulator. If you connect 5V DC directly to a LED without going through a resistor, the LED wont blow off. If you connect 10V directly to the output port of a PIC and ouput a Low on that pin, the pic wouldnt get spoiled too. At most, it would just give you a warning message.

    I guess key bouncing is hard to simulate on a general purpose electronics simulator cause it may take up a lot of processing power, to detect the ON & OFF of the key on nS basis, from your PC and make the OS and other applications run like a tortise. Your mouse would not function properly....etc.

    If I want to simulate key debouncing I'd do it on a real switch or button with a real scope instead of a simulator.:D

    Just my 2 cents.;)
     
  3. crutschow

    Expert

    Mar 14, 2008
    13,028
    3,238
    I know of no switch model in a Spice simulator that models switch bounce. For that you'd have to generate a simulated bounce signal, perhaps with the pulse source or piece-wise-linear source. A Google search of "switch bounce waveform" gave many typical examples to emulate.

    Edit: You can feed that waveform into the voltage-controlled-switch for the switch bounce simulation.
     
  4. ilnar

    Thread Starter New Member

    May 8, 2012
    16
    0
    OOOkay okay, i did it in reality already and filtered it out aswell. it required 100nf capacitor to filter press on bounces and 2 logic gates to filter out press off smoothed output and turned it into edge. thanks for advices. gonna try multisim who knows maybe it will do a thing.

    P.S. a simulated bounce signal was a great idea by the way. but im too lazy to try that :))
     
  5. crutschow

    Expert

    Mar 14, 2008
    13,028
    3,238
    Usually simulation is easier than experimenting with the actual circuit. ;)
     
Loading...