VoltageDivider

Discussion in 'General Electronics Chat' started by Dr.killjoy, Jan 29, 2014.

  1. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
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    I would like help to understanding how voltage dividers work and why the value are being used ???I have been learning how to work out the math and get the results I want but really basic .. But I don't understand how values are figured out and why those particular values are used??? Also how would I look for names in the datasheet as to figuring out what to use for the load rating on the voltage divider ??? I tried the search forum but that seems to be broken lol...


    Also what does this mean too
    Taking from here
    http://forum.allaboutcircuits.com/showthread.php?p=689252#post689252



    Thanks
    Jason SR
     
  2. #12

    Expert

    Nov 30, 2010
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    6,760
    Similar question in Homework right now. The first thing you want to consider when making a voltage divider is, "How much current shall I use?"
    It depends on the load. Rule of thumb: to make sure the load does not affect the voltage divider by more than 10%, the voltage divider must have 10x the current of the load. For 1% precision, use 100 times the current the load will use, and for .1%, 1000 times the current of the load.

    Either that or calculate the current the load will use and design to that load. Not always easy when the load changes. That's why unity gain voltage followers were invented.

    Has this gotten you started, finished, or asking more questions?
     
  3. Dr.killjoy

    Thread Starter Well-Known Member

    Apr 28, 2013
    1,190
    156
    How would you figure load with a co
    uple N channel fets and LM324??
     
  4. #12

    Expert

    Nov 30, 2010
    16,257
    6,760
    Are they the load or the drivers?
    Please post a circuit.