flip flop question for quad encoder based on question-3 of workseet

Discussion in 'General Electronics Chat' started by devalvyas, May 6, 2009.

  1. devalvyas

    Thread Starter Active Member

    Nov 11, 2008
    80
    0
    HI,

    I am building a quad encoder based on Question 3 of the worksheet, using a d-flip flop. Now looking at the output waveform there is a period of 45degrees rotation of the disk,where both the clk and the d input of the flip flop are 1 (logical High).

    Now my question is that when i give power to the circuit, and the disk happens to be in a position where both clock and d input detects a logical high at the same time, then is there any chance of false triggering?

    I mean will there be any false triggering on power start based on the position of the quadrature disk?

    if yes, how to prevent it?

    Also during the time when the pulse input from the led is not detected, will the d flip flop see it as logical low or a floating input as there is no pulse at all, no ground pulse or no high pulse?

    how do i make sure that during the time that ther is no pulse to the d and the clock input, they sees a logical low or ground and not a floating point?
     
    Last edited: May 6, 2009
  2. devalvyas

    Thread Starter Active Member

    Nov 11, 2008
    80
    0
    will using a pull down resistor of around 100k connected to both d and clock input help regarding the floating input?
     
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