Analog vs Digital Servo (1) 

A servo is an electronic device that is used to operate RC cars, RC boat, RC plane, robots, electronic toys, and electrical appliances by determining the motion direction.

Firstly we need to know the technical aspects of a servo and how it works.

Generally, The servo contains: motor, circuit, wires, gear train, output shaft, cases and potentiometer.

1. Potentiometer is a position sensor that is connected to the output shaft. The shaft is attached to the control wheels by gears. The movement and its direction are controlled by an electrical signal.

2. Motor’s function based on the waves of pulses sent by a command, like from a transmitter, to create a mechanical motion.

For example, we use a servo to control steering by adjusting the levers back and forth. We also use a servo to control the speed of a radio control car by connecting it to the engine throttle.

The specification of a servo is normally being set by the turning angle per time at 60 degrees (speed) and the load carrying capacities (torque). There are also weight and dimension in the specifications.

So, how does the servo work?

Servos have three wires that extend from the casing.

Each of these wires serves a specific purpose. These three wires are for the control, power, and ground.

The control wire is responsible for supplying the electrical pulses. The motor turns to the appropriate direction as commanded by the pulses.

When the motor rotates, it changes the resistance of the potentiometer and ultimately allows the control circuit to regulate the amount of movement and direction. When the shaft is at the desired position, the supply power shuts off.

The power wire provides the servo with the power needed to operate, and the ground wire provides a connecting path separate from the main current. This keeps you from getting shocked but is not needed to run the servo.