Page 110 - Make Your Own PCBs with EAGLE from Schematic Designs to Finished Boards

FIGURE 4-25 Bar-code section of the design—direct connections.

Assigning Net Classes

This step is not essential, but it is a good idea. It allows you to specify what kind of net a net is. We
only really have two types of nets in this design—power and signal—but you could imagine a design
that controlled a 110-V relay and had some nets that were high voltage and high current. While this
has no bearing on the schematic, when we come to lay out the tracks on the board, it would be useful
to know that those tracks should be wide and well separated from other tracks. Similarly, it is
common to use slightly thicker tracks for supply nets.

As the design currently stands, all the nets will be of a class called default. If you use the
Information command and select a few nets, you can see the dropdown near the bottom of the window
that allows you to select a class for the net. Currently, there is only one entry there (“Default”). To

add another net class for supply, select the option “Net Classes..” from the Edit menu, and type a
name in the second row (Figure 4-26).