time delay???

Discussion in 'General Electronics Chat' started by vijaytej, Jan 11, 2015.

  1. vijaytej

    Thread Starter New Member

    Jan 11, 2015
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    Why there is a time delay in the output signal of any electronic circuit when compared to input.
     
  2. MikeML

    AAC Fanatic!

    Oct 2, 2009
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    Speed of Electricity (link)
     
  3. MaxHeadRoom

    Expert

    Jul 18, 2013
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    E=mc2 ;)

    Max.
     
  4. vijaytej

    Thread Starter New Member

    Jan 11, 2015
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    Did'nt get you....
     
  5. #12

    Expert

    Nov 30, 2010
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    Zero time = infinite velocity
    Infinite velocity requires infinite energy.
     
  6. wayneh

    Expert

    Sep 9, 2010
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    That defines the minimum delay, but there could be a delay far in excess of the minimum that depends on the circuit function and design. Energy storage in capacitors and inductors, for instance.
     
  7. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    It depends on the circuit and the components used. For starters there is the speed of light in a vacuum, but that is about 1 nanosecond of delay for every 11 inches, rarely enough to worry about unless you are doing very high speed (MHz, GHz, etc.) digital or analog work. Next comes capacitance. All semiconductor junctions have capacitance, and it takes a finite amount of time for each little capacitor to charge up and discharge as it voltage changes with circuit function. It's not much, but it adds up. Similarly, component leads and chip internal connections have inductance, which can work with internal resistance or capacitance to add delay. Then come other capacitors and inductors. For example, in most opamps there is an internal capacitor called a Miller capacitor that works to prevent the chip from breaking into oscillation. But it also limits the gain-bandwidth product of the amplifier and introduces group delay and phase shift, both of which delay the output with respect to the input. These are just some of the sources of signal delay. There are others specific to digital circuits, but the result is the same.

    ak
     
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