Today, servo motors are the primary drivers of many industries. You will find them in any mechanical equipment, from vehicle wipers to washing machines. The motors are small and efficient, making them the perfect options for most machines, from simple appliances to complex robotics. Keep reading to learn more about these high-potential motors and where you can apply them.

What is a Servo Motor?

A servo motor is a type of motor, usually small, operating on electric current and fitted with an actuator to facilitate rotary or linear motion. Think of the type of motor that moves a car's wipers on the windshield. The motors are designed to allow precise velocity control of the motion. Therefore, they are considered as variable speed drivers.

Since they are designed for exact positioning, a lot of industries use them where rapid reversing and precision positioning are needed. Good examples of such machines include robotics, machine tools, automation, and robotics.

How Do Servo Motors Work

Every servo motor is designed with a small motor, servo case, a control circuit, and a potentiometer. The exterior of the motor case comes with output drive gears and spline that are connected to the main circuit. It also features three main wires, ground, control, and power.

To rotate and run the actuator, the motor changes the potentiometer resistance. When running, the shaft changes its position, helping to operate your equipment. One the action or goal is achieved, a signal is transmitted to the sensor that tells the motor to stop.

Apart from internal resistance, servo motors also rely on other electrical pulses with different widths. This type of control is known as pulse width modulation (PMW). It is regulated by the rate of repetition. When PMW is sent to the motor, the rotor is moved by the pulse duration to adjust the positioning of the shaft. Therefore, each pulse’s length moves the motor with a specific distance.

Types of Servo Motors

Servo motors can be broken into two main categories, DC servo motors and AC servo motors. Notably, the DC servo motors are cheaper than the AC motors.

• DC Servo Motors:

As the name suggests, they are designed to run on direct current and small current levels, mainly from batteries. Therefore, they are preferred for smaller applications where precision is needed. Each DC servo motor is made of a gearbox, feed control loop, DC motor, electronic circuit and a potentiometer. It must also feature a DC source. These motors can further be categorized into series, split series, shunt control, and permanent servo motors.

• AC Servo Motors

These motors are made to use direct currents and are able to work with higher levels of current compared to DC servo motors. They are the most preferred option for industrial equipment, from machining tools to conveyors. The main types of AC servo motors include position rotation, continuous rotation, and linear servo motors.

As we have demonstrated, servo motors are pretty small devices, but they have a wide range of applications. They are used in robotics equipment, automatic doors, conveyor belts, textile production and milling machines. Always remember that like other categories of machinery, from pumps to lathe machines, the servo motors should be maintained in top condition for optimal performance.