CHAPTER 10 ■ LEDS
A caliper measures small dimensions. The left side of Figure 10-2 shows a T 1 ¾ LED placed in the jaws
of the caliper. The digital display reads 5.00 mm. SparkFun Electronics sells a digital caliper for $14.95
(part #TOL-10997). You can also find them on auction or machining web sites for approximately the
same price.
Figure 10-1. LED sizes: surface-mount (1.5 mm), small - T 1 (3 mm), standard - T 1 ¾ (5 mm), and jumbo
- T 3 ¼ (10 mm)
Figure 10-2. Measuring an LED diameter with calipers (left). The other end of the calipers protrudes for
measuring the depth of a hole (right)
Although not required equipment, calipers are useful for many tasks in robotic engineering. For
example, calipers can measure the thickness of aluminum sheets, the distance between wires on a
component, or the depth of a screw hole (see right side of Figure 10-2).
LED Shapes
Discrete (individual) LEDs come in a variety of shapes and mounts (see Figure 10-3). The classic bullet
shape (“T”) still dominates, but side view and square styles are available.