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LTSpice question, dependent sources.

  1. Aug 30, 2009 #1


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    I use LTSpice, and vaguely remember there was a way to make a voltage (or current) source depend on either another source in the circuit, or to follow some function of time. I think it's either a source parameter, or a command line placed in the schematic.

    Does anybody know how to do this? I tried searching the LTSpice Yahoo group but didn't find what I'm after.



    FYI, I am trying to model the behavior of a NiCd battery in a charger. I have an equation for battery voltage vs. charge state.
  2. jcsd
  3. Aug 30, 2009 #2
    Hello Redbelly,

    Sure enough, there are three basic dependent sources:

    1. e - Has two inputs and two outputs. Open the symbol and put a gain value in for value 1
    2. bv - Arbitrary voltage source. Open the symbol and type V=v(node) into value, it will output the voltage at [node]. Likewise, you can make it current dependent by entering V=i(part)
    3. bi - Arbitrary current source. Open the symbol and type I=v(node) or I=i(part) into value.

  4. Aug 31, 2009 #3


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    Thanks Mike! And I see that bv and bi can be defined with any arbitrary function, which is just what I need.

    Thanks again,

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