PI Expert will design and document a complete power transformer to meet your specifications. However, PI Expert also gives you the ability to design and document a completely custom transformer. This includes everything from the core and bobbin combination to the winding stacking configuration, winding order or even what margin tape to use. There are a number of help topics dedicated to explaining how to use PI Expert's numerous features to help you design and document the exact transformer you want to use. They are summarized and grouped below.
The most important component to consider while designing a custom transformer is the core. PI Expert comes with a number of common cores but also allows you to enter custom core data using the Core Library. You can optimize using this custom core or select the core manually using the Core Selection dialog. See the Core Library topic for details on adding custom cores to the Component Library and using these cores in Component Sets.
Another important choice while designing a custom transformer is which bobbin to use. Your choice of bobbin will be dictated by a number of factors including the number of pins needed to properly terminate each winding, the orientation (horizontal or vertical for example) of the bobbin, and the winding window area. PI Expert includes many common bobbins, but you can also enter your own custom bobbins using the Bobbin Library and then choose these bobbins using the Bobbin Selection dialog.
You can also view and edit the specification for electrical strength, the nominal primary inductance (LP) and the maximum leakage inductance using the Requirements and Test dialog.
You can also specify all primary winding parameters, such as wire size, filar, start and termination pins and winding options using the Primary and Bias dialog. Similar parameters can be specified for all secondary windings, including winding order and wire type to use by using the Secondaries dialog.
In some cases you can also choose to have the software automatically design shield windings or a flux band to help reduce EMI. If you're using the New Design Wizard, you can enable the use of shields using the Design Settings dialog. If you have already completed a design and would like to either enable or disable the use of shield windings, use the Shields dialog.
If you would like to edit the transformer materials list generated by PI Expert, use the Materials dialog. Additionally, you can edit or add any comments about the transformer in the Comments dialog. Use these two dialogs for any minor modifications or notes that can not be included elsewhere.
PI Expert considers the numerous combinations of output stacking configurations during optimization. However, PI Expert also allows you to specify your own stacking configuration using the Stacking dialog.
You can also specify the required safety spacing not only through the Bobbin Selection dialog, as mentioned before, but also by using the Safety and Thermal dialog.
Using the Key Parameters dialog, you can manually enter the number of secondary turns on the main output in addition to modifying the turns ratio by adjusting VOR.
In some designs the use of a bias winding is optional. You can enable or disable the bias winding using the Design Options dialog