How does the switching decoder work

Discussion in 'General Electronics Chat' started by eggtree, Jan 6, 2007.

  1. eggtree

    Thread Starter Member

    Nov 28, 2006
    27
    0
    How does the switching decoder work?

    I mean in digital operation (0=off,1=on).Using transistor as a switch.

    btw,Im a very new babe.
     
  2. mrmeval

    Distinguished Member

    Jun 30, 2006
    833
    2
    What do you mean by switching decoder? Do you have circuit or part datasheet?
     
  3. Dave

    Retired Moderator

    Nov 17, 2003
    6,960
    143
    A quick search of the net indicates that a "switching decoder" is a normal decoder featuring one or more relays. Other than that I cannot find any proper information regarding how one would work.

    Dave
     
  4. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    Hi,

    If you're just concerned with the single transistor, remember that a logic 0 is also 0 volts, while a logic 1 is a positive voltage - usually 3 to 5 volts, depending on the logic family used.

    In the case of a transistor, it is going to be in a common emitter arrangement, so the voltage on the collector will be 0 when the transistor is on - a logic 0. When the transistor is off, the collector will have the full voltage on it, for a logic 1. It just switches between those two states.
     
  5. Papabravo

    Expert

    Feb 24, 2006
    9,898
    1,722
    In 37 years of engineering design I never heard of such a thing. Can you elaborate?
     
  6. hgmjr

    Moderator

    Jan 28, 2005
    9,030
    214
    Greetings eggtree,

    I too am unfamiliar with the term "switching decoder". Perhaps it is just a matter of terminology.

    If you are referring to a specific device then it would be helpful if you can provide a part number and manufacturer for the device so that we will have a place from which to begin assisting you with your inquiry.

    If you are referring to a process or technique then it would be helpful if you could elaborate.

    hgmjr
     
  7. eggtree

    Thread Starter Member

    Nov 28, 2006
    27
    0
    Sorry for the confusion as a new babe iand m not good in expressing technical things.

    Currently, im in the planning stage of a project.There are 4 on/off switch and 4 boards.Each time, only 1 board can turn on and the rest are off.

    I will do up a truth table and use some transitor switch for the logic '1' ON and OFF '0'.

    The problem is I do not know how the transitor is wire together.I m not asking for expert here to do my work. I just want to know the logic.

    Example, some IC logic chips has got nothing but many wire up transistors. I just want to know how this work.

    Thanks.
     
  8. Papabravo

    Expert

    Feb 24, 2006
    9,898
    1,722
    Well one thing that comes to mind is four 4-input AND gates, one for each board. The board will be turned on IF the corresponding switch is closed AND the other three switches are open. Same logic for each board. I suppose you could do it with discrete transistors the way Diode Transistor Logic was done 45 years ago or so.
     
  9. m4yh3m

    Senior Member

    Apr 28, 2004
    186
    39
    eggtree, are you aware of how logic gates work? If so, then you simply need to view the data sheet for your ICs, which will show you what functions they perform and how to connect them.

    Which brings up a question I thought of a while back...*goes to make new post*
     
  10. m4yh3m

    Senior Member

    Apr 28, 2004
    186
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