Exporting a Circuit From an Imported Table

To create a circuit from an imported table, you need to have a table file containing tabular data. The first row in the file must contain the column names. The table export feature writes other useful information into subsequent rows, but the import succeeds whether or not this information is present. The rows of tabular data come next.

Note: In Maxwell, global variable names begin with the $ character. However, when you are creating an ECE .sml model, this character causes the circuit to fail when importing it to Twin Builder. To resolve this, when the circuit is exported, the $ character is replaced by the _ character. For example, the project variable $MyVar is converted to _MyVar.

To export a circuit from an imported table:

  1. Click Maxwell 3D or Maxwell 2D > Export Equivalent Circuit > From Imported Table.

The Select File dialog box appears.

  1. Find and select the file containing the table you want to use.
  2. Click Open.

The General window appears, allowing you to specify basic information about the circuit model.

  1. Select one of the following from the Model Type drop-down menu:
    • Linear Motion
    • Rotational Motion
    • Matrix
    • Lookup Table
  2. Select either Ampere-Turns or Amperes as the Current Source Variables option.
  3. Click Next.

    4. The Table window appears, allowing you to set up the inputs and outputs for the circuit equivalent. Most of the values have been automatically filled in, based on your design. You can keep the defaults or change the selections and values for the various parameters.

  4. To apply deep spline interpolation to all inputs in the circuit PWL model, select the Use Bezier Interpolation check box.
  5. To export the data to a table that you can edit and use to export an equivalent circuit at a later time, do the following:
    1. Click Export Table. The Save As dialog box appears.
    2. Select a location, and type a name in the File name box.
    3. Click Save.

    The Table window reappears. The file that is created contains header rows with information such as name, i/o, and type, plus all of the actual data. You may export the table to view or use in external programs. You can also modify the exported table file and then re-import it to create an equivalent circuit. On import, the information in the header rows is used as default settings in the circuit export dialog box.

    Note: The Table window is the last step for the Lookup Table model type. For all other model types, there is one more step: the Terminals window.
  6. For model types Linear Motion, Rotational Motion, and Matrix, click Next.

    7. The Terminals window appears, allowing you to set up terminals, which are nodes with “through” and “across” data. Most of the values have been automatically filled in, based on your design. You can keep the defaults or change the selections and values for the various parameters.

  7. Enter a Scaling Factor in the text box. The scaling factor is applied to all output quantities and can be used, for example, to scale data from partial models that take advantage of symmetry.
  8. Optionally, specify the Model depth for 2D XY models for scaling.
  9. Optionally for 2D XY Rotational Motion model type, specify the Skew angle.

    10. When a stator core or rotor core is skewed for a 2D Rotational Motion model, the flux linkages and torque of the look-up table will be modified based on the skew angle θk.

    For any output of the look-up table, f(θ), where θ is rotor position, the modified output will be

  10. Specify the Terminals:
    • To specify a coil terminal:
      1. Select a Source for the Flux or Charge, depending on whether your design is mechanical or electrical.
      2. Enter a Resistance.
      3. Enter the number of Turns in the coil winding.
      4. Enter the number of Branches.
    • To specify a mechanical terminal:
      1. Select the Force (or Torque) variable from the drop-down menu.
      2. Select the Position variable from the drop-down menu.
      3. Optionally for Rotational Motion model type, select Use rotational velocity.
  11. Click Finish to export the equivalent circuit.