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 Simple example of a working transformer (XFRM) 

Last post Sun, Sep 30 2012 9:23 AM by Shiraz. 3 replies.
Started by Shiraz 28 Sep 2012 09:17 AM. Topic has 3 replies and 5837 views
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  • Fri, Sep 28 2012 9:17 AM

    • Shiraz
    • Not Ranked
    • Joined on Sun, Sep 23 2012
    • Posts 15
    • Points 195
    Simple example of a working transformer (XFRM) Reply

    So I am trying to get a simple example of a working transformer (XFRM) to work.

    I know other people have got it to work successfully:

    see here:

    1) www.seas.upenn.edu/~jan/spice/PSpicePrimer.pdf

    2)  eece.ksu.edu/~rdmiller/PspiceTutorialv14-2Schematic.doc

    So I tried to get a simple XFRM_NONLINEAR\BREAKOUT (TN33_20_11_2P90) to work. But I am getting one of two errors here:

    ERROR(ORPSIM-15142): Node N00182 is floating

    ERROR(ORPSIM-15142): Node N00196 is floating

    ERROR(ORPSIM-15143): Voltage source and/or inductor loop involving
    V_V1. You may break the loop by adding a series resistance

     

    I have uploaded a simplest possible template project here : 

    https://docs.google.com/open?id=0BwG45lg3wcwnTnVYVWhTSWN2ZTg

    • Post Points: 20
  • Fri, Sep 28 2012 11:55 AM

    • oldmouldy
    • Top 10 Contributor
    • Joined on Tue, Jul 15 2008
    • Woking, Surrey
    • Posts 1,439
    • Points 24,500
    Re: Simple example of a working transformer (XFRM) Reply

    Since you are trying to learn something, consider the following:

    All voltage nodes in PSpice, and indeed SPICE, need a path to the 0 node, if you want "isolation" provide a path, like a 1G resistor to the 0 node. Now take another look at the primary circuit, why might the nodes be "floating"?

    Error messages convey information - "Voltage and / or inductor loop" - wound components have back EMF, modelled voltages sources have no internal resistance, oops! infinite current possibilities, as the message says "add a resistor" between the voltage source and the inductor to break the loop, "real" wound components have series resistance, models are ideal, try a 1 ohm resistor in the primary circuit and see if that helps, you can always reduce the value, the resistance value can be "small" but it can't be zero.

    Name the circuit nodes with a net alias, Place>Net Alias, you don't need anything to taxing, use IN, OUT, and A, B, C and D if you can't come up with anything better. It will be much easier to locate a named net than a system assigned "N" net name default.

    In recent versions, like releases since about 2001, you can't "drop" components onto wires and break them, draw the connections "properly", things are usually in a bad way if the schematic is littered with Junction Dots at component pins.

    • Post Points: 20
  • Fri, Sep 28 2012 12:40 PM

    • Shiraz
    • Not Ranked
    • Joined on Sun, Sep 23 2012
    • Posts 15
    • Points 195
    Re: Simple example of a working transformer (XFRM) Reply

     Thanks for your response.

    1) some people had the circuit working without the series resistor between the AC source and the transformer.  But I did end up putting the resistor and it now works perfectly...

    2)  Thanks for the tip on net aliases that was very helpful because I was like "how do you locate these nodes"?

    3)  I deliberately go about and cause the wires to go over the edge of the component's end (just a little bit) . I do this to ensure that the component is connected. I also do this because I read in (Sidiku/ Alexander Circuit Analysis book which has a PSPice tutorial at the end) that the pink dots ensure that there is a connection and there are no floating nodes/ components. But you are telling me something different. I also verify that a component is connected by moving the component up and down and seeing how the wires behave. 

    Anyways this thing has been a bit frustrating as of yet. Hope to be over these issues soon :) Thanks very much once again for the pointers and the help. I am still looking for PSPICE tutorials so if there are better ones I would love to go through them. I have gone through 3 already I think.

     

     

    • Post Points: 5
  • Sun, Sep 30 2012 9:23 AM

    • Shiraz
    • Not Ranked
    • Joined on Sun, Sep 23 2012
    • Posts 15
    • Points 195
    Re: Simple example of a working transformer (XFRM) Reply

    So one one version of my machine I had to change the "Implementation" key to a value of "kbreak"; see here:

    Or paste this url : http://translate.google.com/translate?hl=en&sl=ja&u=http://cas.eedept.kobe-u.ac.jp/~arai/pspice/chap7.html&prev=/search%3Fq%3DModel%2BTN33_20_11_2P90%2Bis%2Bundefined%26hl%3Den%26client%3Dfirefox-a%26hs%3DEl2%26rls%3Dorg.mozilla:en-US:official%26biw%3D750%26bih%3D648%26prmd%3Dimvns&sa=X&ei=v29oUL_8IKPz0gGhqYHICg&ved=0CCUQ7gEwAA

     

    I had to do this because I kept getting the error : ERROR(ORPSIM-15113): Model TN33_20_11_2P90 used by X_TX1.K_TX1 is undefined

    Now why was that happening ? It was not happening on other machines but it is happening on my laptop (with the lite version or student version?). 

     Thanks everyone for all the help particularly the gentleman with the alias "ol_mouldy" 

     

     

    • Post Points: 5
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Started by Shiraz at 28 Sep 2012 09:17 AM. Topic has 3 replies.