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Anyone really familiar with Altium?

Discussion in 'General Electronics Discussion' started by Mitchekj, May 2, 2010.

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  1. Mitchekj

    Mitchekj

    288
    0
    Jan 24, 2010
    Appreciate any help, hopefully someone knows all about Altium's sim feature...

    I'm trying to run a sim on a startup circuit for a flyback SMPS. I've got it all working as I'd expect, though one issue I'm having is trying to change two parameters at once and having them plot dependently.

    This may be hard to explain, but here goes: (see attached for sim schematic and outputs)

    The circuit generates Vcc from the rectified mains to get the IC switching, which starts the aux coil generating Vcc, which then shuts down the transistor once it gets above (actually just below) the zener voltage.

    The 169V source would be the rectified mains, after the input bulk cap and just before the transformer primary.
    The 100kHz pulse (at +20-30V) is simulating the aux coil of said transformer. (Vcc coil.)
    Load R3 is simulating the controller IC's VCC input. (Draws ~10mA.)

    In the SIM, I'm sweeping amplitude of the two sources (169V, and 100kHz pulse) up from 0 to max. Max being 169.7V and 30V, respectively. Trying to get a small delay between the two sweeps is not working so hot. But I can live with that.

    What I'd like to do is get the output graphs to put both sweeps into the same line plot. See the bottom graph Q1(p). The x-axis is representing the 100kHz pulse sweep, the y-axis is the power dissipated in Q1. The different yellow lines are the sweep of the 169V source. To be accurate, these yellow lines should be a singular line, which would start low, rise to a peak, then fall sharply at about the 12V (on the x-axis) point.

    That's what I mean about graphing them into a dependant single line, anyhow, since the voltage levels of the two sources are interdependant. i.e. If Vrec falls to 130V, then Vaux will in turn fall, to ~23V.

    Am I just going to have to set the sim schematic up that way, by modeling the transformer, etc? Or is there a way to get the sim program to model that? So far I haven't found a way. :(

    Thanks for taking the time to ponder this, those who do! :)
     

    Attached Files:

  2. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    Not really familiar with the Altium simulation system, but here are a few ideas.

    I understand that Altium has a really active company owned forum. Only licensed owners are allowed access. Talk to the local sales rep or the corporate support to get login. In the long run, that will be your best bet.

    Can the program output raw data that it is using for the plots? Can you get it in CSV format? If so, you can import it in a program like Excel and plot it the way you like. The worst case is that you need to run a number of simulations and combine the dataset, but it can be done in short order.

    I admit that I have not fully understood the problem and do not have the time right now to delve into it. So there may be a simpler answer that I am missing.

    ---55p
     
  3. Mitchekj

    Mitchekj

    288
    0
    Jan 24, 2010
    Thanks for that. I'll have to see if I can get that raw data, I'm sure it's somewhere, good idea. I have the support forum login at work, but I've never used it. I'll have to try that tomorrow.

    I just get impatient when I get something in my head... hehe.
     
  4. 55pilot

    55pilot

    434
    3
    Feb 23, 2010
    After you run the simulation, look in the project directory and sub-directories with Windows Explorer. I doubt the program will keep that much data in RAM. Its is likely sitting in a file on disk. The bad news is that it may not be in a format that you can actually use.

    ---55p
     
  5. Mitchekj

    Mitchekj

    288
    0
    Jan 24, 2010
    There's a folder w/ the project outputs, but all the files are not human-readable, as you'd guessed.

    As a workaround, I removed the 100kHz supply, and just used a divider from the 169V line in its place... at least it got me the slope I was looking for. Just need to tweak the values so all the numbers match up.
     
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