next to the Sleeving box to edit the value. Select Yes to include sleeving around wires, or No. The user selected icon 
indicates the custom margin value. Click this icon to restore the default value.The Bobbin Selection dialog allows you to select which bobbin you want to use with a specific core along with a number of other options.
Check the calculator icon next to the Sleeving box to edit the value. Select Yes to include sleeving around wires, or No. The user selected icon indicates the custom margin value. Click this icon to restore the default value.
PI Expert will try to meet the specified safety spacing using the bobbin selected. You can enter the total amount of safety margin to be used (added using margin tape) during transformer construction by clicking the calculator icon next to the Margin on Left (Bottom) or Margin on Right (Top) boxes. These values are also automatically adjusted depending on the bobbin's built-in safety spacing. The build-in safety spacing refers to the distance measured from the pins to the winding area. For safety approved bobbins the secondary side of the bobbins has an extended creepage distance to allow for non-margin designs using triple insulated wire. The user selected icon indicates the custom margin value. Click this icon to restore the default value.
You can check values for Number of primary and/or secondary pins used. The values can be edited in Pin Allocation dialog box.
The table displays the available bobbins for use with the specified core and each bobbin's associated information. The target icon 
will be placed next to the core that has been chosen by PI Expert. You may select a different bobbin to use in the design by clicking on the row of the bobbin desired. The user selected icon will appear next to your selection. You can also optimize the design using your manually selected bobbin. If you would like to discard your manual bobbin selection, you can click the Auto Pick button and the auto pick icon 
will appear in the row of the bobbin PI Expert chooses.
The default Component Library that is provided with PI Expert usually has only one bobbin associated with each core. This is the default bobbin for the core. You can add more bobbins using the Custom Component Library and Custom Component Set feature of PI Expert. Please see the Custom Transformer, Bobbin Library and Core Library help topics for more information on adding additional bobbins.