on the right of the parameter box. The 
icon indicates that a custom parameter value has been entered.Use the Output Heatsink form to review the output heatsinks used in the current design. PI Expert selects the output heatsinks during optimization and tries to select the most effective one. You can change the automatically chosen heatsink by clicking the Change button. The main output is marked with the M symbol.
To change the automatically selected heatsink, click the Change button. In the Losses and Heatsink estimation dialog box you can view and edit the heatsink parameters.
PI Expert calculates the components set automatically. You can manually change the temperature limit by editing the value in Acceptable Temperature Rise box. To edit the temperature click the calculator icon on the right of the parameter box. The icon indicates that a custom parameter value has been entered.
The Heatsink Type is re-calculated automatically depending on the acceptable temperature value. You can select another heatsink type by click the calculator icon on the right of the Heatsink Type box. The available heatsink types are Copper PCB, Aluminum Extruded, Custom Aluminum and Custom Zinc Plated Steel.
For each heatsink type the parameters are displayed in the bottom part of the Heatsink design form. When you have the Aluminum Extruded type selected you can change the thermal resistance. To do this in the Thermal Resistance box click the black down arrow control on the right of the calculator icon and select Change. In the Heatsink dialog box, select the component you want to add. Click OK. The The icon indicates that the custom selected resistance is chosen. To restore the default resistance click the black down arrow control on the right of the icon and click Default.
For Custom Aluminum and Custom Zinc Plated Steel types you can change the heatsink height value. To do this click the calculator icon on the right of the Heatsink Height box. Edit the parameter value. The icon indicates that a custom parameter value has been entered. To restore the default value click the icon.