In this chapter, we will select and install motors in the line-following robot circuit. You'll also learn a little about diodes.
In choosing motors for the line-following robot, consider the following criteria:
The motors should operate at voltage ranges provided by a 9 V battery. That's slightly less than 10 VDC, down to 7 VDC.
The motors should be small enough to fit abreast within a sandwich container. That means each motor may be no more than 6 cm in length and 4 cm in diameter. Motors with smaller dimensions are even better, as you can add tubes or other ornamentations.
The loaded motor speed should not be so slow as to bore people, but not so fast as to drive the robot off of the course. ...