How RC servo motor works

RC servo motors have a large range of speeds,sizes,weights,shapes or colours,but they all work on the same principle.

Most servo motors contain several main parts:

The controller circuit:

Controller circuit is the brain of the Servo. This circuit can read the user's operating signal  and translate it into a motor revolution in such a way, that the drive shaft will be rotated to the desired position.

The feedback potentiometer: 

The shaft of the potentiometer is attached to the drive shaft of the servo. When the drive shaft rotates, so does the potentiometer. In that way, each and every rotation angle of the drive shaft, corresponds to a different resistance of the potentiometer. By reading the potentiometers' resistance, the controller is able to know the exact angle of the drive shaft of the servo.

The motor:

This is usually a small high speed DC motor controlled by a H-bridge circuit attached to the servos' controller.

The gearbox: 

The gearbox will drive the motor's revolution to the drive shaft. Also, the rpm will be significantly reduced and the torque will be increased. The torque is one of the main characteristics of RC servos.

The drive shaft: 

When all of the above operate in perfect harmony, the drive shaft will be rotated with accuracy to the user's requested angle.

How to choose servo motor size

I think it all depends on the size and type of your rc  plane. For example, if you want make a  large 3D plane, you need  to buy some good quality digital servos with a high amount of torque. For small airplane, any 9 gram servos will be ok.

What is servo motor

RC Servo are very popular parts when you make RC models. No matter if this is aplane or helicopter,  train model, or a car, or a boat, there must be at least one servo hidden somewhere within the constructions.

RC Servo are used to convert electrical signal into polar or linear movement. A simple example is the steering system of an RC car. When signal is transmitted from the control to the car, this signal is decoded and sent to a servo. According to this signal, the servo will rotate it's drive shaft for some degrees, and this rotation is translated into wheel steering.

The reason that makes those servos vary handy is that, they have a very easy (and universal) way of driving them with a simple PWM circuit, they can achieve from low to higher torques, enough to move almost everything needed in an RC model, they are very compact and reliable, and most of all, they come with very low prices according to their specifications.

Micro 9g Analog Servo motor

Micro 9g Analog Servo motor

Stander 38g Servo

Stander 38g Servo

First time to blogger,introduce myself to everyone

My name is tim.I am from china.And I work in topjoyo technology co., limitied.

Topjoyo technology is specialized in researching, developing, manufacturing and selling RC servo motor.Our servos are selling well all over the world,we also  have held he good reputation from our customers.

If anyone have demand on servo motor or other things that you want to know about,pls contact me.I will provide you best service.