Page 61 - Make Your Own PCBs with EAGLE from Schematic Designs to Finished Boards

FIGURE 3-1 United States and European circuit symbols.

In this book, we will stick to the U.S. circuit symbols largely because the useful Adafruit and

Sparkfun libraries are in this format. If you feel strongly about using the European-style symbols, then
you can search out circuit symbols in that standard.

Resistors

Resistors are probably the easiest components to find in a library. They are pretty standard in size,
with relatively few different sizes to choose from, both in through-hole and surface-mount device
(SMD) forms.

Through-Hole Resistors

For most though-hole designs, ¼-W metal-film resistors are fine. These normally will be mounted flat

against the PCB with the leads bent at right angles at the ends of the resistor bodies. This usually
requires a 0.3-in. separation. Figure 3-2 shows a selection of through-hole resistors. The resistor
power ratings from front to back are 125 mW, ¼ W, and two 1-W resistors.