Servo Motor Control: The Servo Motor

Inside the Servo Motor
           Like DC motors, servo motors have been around a long time and are used in a wide variety of applications. The basic design of the servo motor is the same no matter the size or manufacturer. The picture below illustrates a cut-away of a servo and shows you what it looks like on the inside.

           The bottom has the servo controller board which interprets the signal input & turns on the motor inside which is geared up. You cannot see it clearly but there is also a potentiometer (aka a varible resistor) inside the servo as well. The servo uses the potentionmeter for finding the different angles that it will rotate to. These so called "pots" can go bad so, don't automatically throw away servos if they don't work properly, often times all that needs to be replaced is the pot inside.

Servo Motor in Action
           To illustrate how to control a servo motor, first we'll look at the sample program in action. The video below shows a pic controlling a servo. It tells the servo to move to three distinct locations over and over forever: 0°, 45° & 90° (Note standard servos can rotate a maximum of 90°).