Servo motors are driven by sending a PWM signal through the control wire while power is given to the motor. Servos need braking circuitry and logic to slow down the rotor and hold its position after braking. We always like to talk about driving motors, but rarely do you hear anyone talking about braking motors. Note that not all servo motors have an encoder.īraking.

This can be done with a specialty drive controller or an MCU. Highly accurate speed can be maintained through feedback control.įeedback loop and drive adjustment. The control and sensing circuit determines the location and speed of the rotor as the motor operates. By adjusting the duty cycle, the rotation rate can be adjusted. A PWM signal is used in servo motors to force the rotor to turn to a specific position. Some sensors that provide this feature are integrated potentiometers, Hall effect sensors, or LED with a photogate and photodiode.ĭriving a servo motor consists of two critical elements as part of driving and control circuitry:Īdjustable drive signal. In a servo motor, control is applied through a feedback loop between the motor and the controller, and the position/speed of the motor is sensed with integrated encoders in the motor. Rather, the term “servo” refers to the way in which a motor is driven and its position, velocity, and acceleration are controlled. How to Drive a Servo Motorīefore getting into how to drive a servo motor, those who are new to working with servo motors should know that a servo motor is not a specific type of motor. Let’s look at the components you’ll need for driving and controlling servo motors, as well as some component options on the market for your next electromechanical system. Instead, you can find servo controllers on the market with the right electronics search engine. Unless you’re working with a high power servo, you don’t need to use discrete semiconductors to build your driver circuit. The question of how to drive a servo motor requires looking at how sensing is implemented and the type of motor being driven. Although this type of motor requires a closed feedback loop, integrated encoder, and control algorithm, the position and speed control they provide makes them highly adaptable in a number of applications.

One type of motor found in many consumer and industrial products is a servo motor. We don’t always talk a lot about electromechanics around here, but driving and control of small motors are important topics.

Servo motor driver circuit