Page 154 - Making things move_ DIY mechanisms for inventors, hobbyists, and artists

134 Making Things Move

FIGURE 6-8 Relationships among speed, power, efficiency, current, and torque in DC motors

Standard hobby servo motors are just little DC gearhead motors with some smarts
in them, as shown in Figure 6-9. When you give the smarts a certain kind of pulse—
basically just turning the power on and off in a specific pattern—you’re actually telling
the servo motor where to point the shaft.
Instead of having just two wires
you attach to a power source like FIGURE 6-9 Anatomy of a hobby servo motor
the DC motors described earlier, (image used with permission from ServoCity)
these motors have three wires and
DC Motor
are controlled by pulses. Standard
servos have ranges between 60° gears
and 270° (typically 180°), so they
are most useful for pointing and potentiometer
positioning tasks. They also typically circuit board
with control
use 4.8V to 6V.
electronics