basic techno.

Discussion in 'General Electronics Chat' started by chyadesh, Apr 18, 2009.

  1. chyadesh

    Thread Starter Member

    Apr 10, 2009
    what do we really mean by analog signals?

    Such that we don't really required any biasing during switching. But biasing is requried in analog circuits.:)
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    Analog signals do not have discreet steps. Digital signals do - most commonly fully on and fully off.

    Biasing of an analog amplifier allows us to keep the "middle" of the input signal in the "middle" of the linear region of amplifier operation.;)
  3. Wendy


    Mar 24, 2008
    The world is analog, audio most definately is analog, when the telephone was invented digital wasn't even a concept.
  4. RAH1379

    Well-Known Member

    Dec 13, 2005
    analog is like turning on a water facet, it can be on a little or alot or inbetween. digital is like turning on a light switch in your room, it is on or off basically
  5. RAH1379

    Well-Known Member

    Dec 13, 2005
    what about the telegraph?
  6. leftyretro

    Active Member

    Nov 25, 2008
    Good one, it's a little of both in my opinion.

    Digital because the key is either down or not, but analog in that the length of a dit or dot can be variable.

  7. studiot

    AAC Fanatic!

    Nov 9, 2007
    Biasing is at least as important in the digital world as the analog one. This is because if you kick a digital input that is floating at an indeterminate level you can get an indeterminate ouput. This corrupts your digital data with possibly serious consequences. So we tie (bias) a digital input to a known level eg zero or line voltage.

    Of course the whole picture is more complicated than just dividing the electronic world into digital and analog. This bipartite classification does not cover the whole scene.

    For instance inverter pulses generated in a switching system (power supply whatever) are not really digital, but we try our best to avoid the linear region of operation in the semiconductor devices, switching from full off to full on and back, so they are not really analog either.

    The word linear brings me to one clear distinction. The inputs and outputs of a digital system are normally at the same voltage level. If they stray too far from this, errors ocur.

    On the other hand in an analog system the ouput voltage is some well defined function of the input. The simplest is a linear relationship, where the output is proportional to the input either as a multiple or fraction. More complicated systems where square laws (radio detectors) or logarithmic laws are also used.

    So there are really several classification schemes covering electronics, but none cover the full range of possibilities. Nor do these schemes fully overlap so we need more terms.