Servo Motor, what's inside?

Alphabets Sounds Video

share us on:

The lesson explores the inner workings of a servo motor, detailing its components such as the housing, gears, circuit board, and potentiometer. It explains how the motor converts high-speed, low-torque input into low-speed, high-torque output, and how it uses PWM signals to determine its position through feedback from the potentiometer. Overall, the lesson provides a comprehensive overview of how servo motors operate and are controlled.

Servo Motor: What’s Inside?

Have you ever wondered how a servo motor works? Let’s dive into its fascinating world and explore what’s inside!

Understanding the Basics

When you look at a servo motor, you’ll notice a main housing with some wires coming out of it. Typically, the red wire is for positive voltage, the brown wire is the ground, and the orange wire carries the pulse width modulation (PWM) signal. However, these colors might differ depending on the manufacturer.

The Gears and Motor

On top of the servo motor, there’s a small gear called a spline gear. You can attach different parts to this gear to make use of the motor’s rotation. Inside, the motor spins really fast but doesn’t have much force, or torque. To fix this, gears inside the servo convert the fast speed into a slower speed with much more torque.

For instance, if the motor spins at 259 revolutions per minute (RPM) with a torque of 1 Newton meter, the output might be just 1 RPM but with a torque of 259 Newton meters. This shows how the servo changes high-speed, low-torque input into low-speed, high-torque output.

The Circuit Board and Potentiometer

Inside the servo, there’s a small circuit board connected to the motor. This board controls how the motor turns. There’s also a potentiometer linked to the output gear. As the gear turns, the potentiometer changes its resistance, helping the circuit board figure out the gear’s position.

How the Servo Knows Where to Go

A controller, like an Arduino or a servo tester, sends a signal to the servo motor to tell it where to move. This signal is a PWM signal, which sends voltage pulses through the wire. The width of these pulses decides the servo’s position: a wider pulse moves it one way, and a narrower pulse moves it the other way.

The Role of the Circuit Board

When the signal reaches the servo’s circuit board, it’s turned into a voltage and sent through a comparator to a motor driver. The motor driver uses an H-Bridge circuit to control the motor’s direction.

The Potentiometer’s Feedback

The potentiometer acts like a voltage divider. When voltage is applied, the change in resistance gives feedback about the servo’s position. The comparator checks the potentiometer’s voltage against the controller’s signal. If there’s a difference, the motor turns until the difference is minimized, meaning the servo is in the right position.

Want to learn more about engineering? Check out some videos online and follow us on social media for the latest updates!

  1. What new insights did you gain about the internal components of a servo motor from the article?
  2. How does the explanation of the gear system in a servo motor change your understanding of how torque and speed are managed?
  3. Reflect on the role of the circuit board and potentiometer in a servo motor. How do these components contribute to the motor’s functionality?
  4. In what ways did the article clarify the process of how a servo motor receives and interprets signals from a controller?
  5. What aspects of the servo motor’s operation were most surprising or intriguing to you, and why?
  6. How might the knowledge of servo motor components and their functions influence your approach to using or designing with servo motors?
  7. Consider the explanation of PWM signals in the article. How does this deepen your understanding of signal processing in electronics?
  8. What further questions do you have about servo motors or related technologies after reading the article?
  1. Build a Simple Servo Motor Model

    Gather some basic materials like cardboard, straws, and rubber bands to construct a simple model of a servo motor. Focus on replicating the gear system and demonstrate how the motor’s speed is converted into torque. This hands-on activity will help you understand the mechanics inside a servo motor.

  2. Explore PWM Signals with an Arduino

    Use an Arduino board to generate PWM signals and control a small servo motor. Experiment with different pulse widths to see how they affect the motor’s position. This activity will give you practical experience with how PWM signals control servo motors.

  3. Disassemble a Servo Motor

    Carefully take apart an old or inexpensive servo motor to examine its internal components, such as the gears, circuit board, and potentiometer. Document your findings and try to identify each part’s function. This exploration will deepen your understanding of the servo motor’s construction and operation.

  4. Create a Servo Motor Animation

    Use animation software or a simple drawing tool to create an animation that illustrates how a servo motor works. Include the flow of signals, gear movement, and feedback from the potentiometer. This visual representation will help reinforce your understanding of the servo motor’s processes.

  5. Design a Servo-Controlled Project

    Think of a simple project, like a robotic arm or a small vehicle, that can be powered by a servo motor. Plan and sketch your design, focusing on how the servo motor will be integrated and controlled. This creative challenge will encourage you to apply your knowledge of servo motors in a practical context.

Here’s a sanitized version of the provided YouTube transcript, with unnecessary details and repetitive phrases removed for clarity:

When we look at a servo motor, we see the main housing with electrical connections entering the side. In this case, the red wire is the positive voltage wire, the brown wire is the ground, and the orange wire is the pulse width modulation (PWM) signal wire. These colors can vary by manufacturer.

On the top, we find a small spline gear to which we can connect various attachments to utilize the rotation inside the unit. The motor has a high rotational speed but low torque, so gears are used to convert this into low speed but high torque output.

For example, if the input is 259 RPM with 1 Newton meter of torque, the output would be 1 RPM but 259 Newton meters of torque. This demonstrates the conversion of high-speed low torque into low-speed high torque.

The DC motor is connected to a small circuit board inside the unit, which controls the rotation and direction of the motor. A potentiometer is also connected to the output gear of the servo. As the final gear rotates, it changes the resistance of the potentiometer, allowing the circuit board to determine the position of the output.

A controller sends a signal to the servo motor to determine its position. This could be an Arduino or a simple servo tester. The signal is a PWM signal, which sends pulses of voltage down the wire. The width of the pulse determines the position of the servo; a wider pulse moves the servo to one side, while a narrower pulse moves it to the other.

The signal enters the servo’s circuit board, where it is converted to a voltage and passed through a comparator to a motor driver. The motor driver controls the rotation of the DC motor using an H-Bridge circuit to manage the direction of rotation.

The potentiometer acts as a voltage divider. When a voltage is applied across it, the change in resistance provides feedback on the position of the servo. The comparator compares the voltage of the potentiometer to the controller signal. If there is a difference, the motor will turn until the difference is minimized, indicating that the servo is in the correct position.

Check out one of the videos on screen now to continue learning about engineering. Don’t forget to follow us on social media for more updates.

This version maintains the essential information while removing extraneous details and repetitive phrases for better readability.

ServoA device used in robotics that allows for precise control of angular or linear position, velocity, and acceleration. – The robot’s arm uses a servo to accurately pick up and place objects.

MotorA machine that converts electrical energy into mechanical energy to create motion. – The motor in the robot helps it move forward and backward.

GearsRotating machine parts with cut teeth that mesh with another toothed part to transmit torque. – The gears in the robot’s drivetrain ensure smooth and efficient movement.

TorqueA measure of the force that can cause an object to rotate about an axis. – The robot’s wheels need enough torque to climb up the ramp.

CircuitA complete and closed path through which electric current can flow. – The engineers designed a circuit to power the robot’s sensors and motors.

PotentiometerAn adjustable resistor used to measure the position or angle of a moving part. – The robot uses a potentiometer to determine the angle of its arm.

SignalAn electrical impulse or radio wave transmitted or received. – The remote control sends a signal to the robot to change its direction.

VoltageThe difference in electric potential between two points, which causes current to flow in a circuit. – The robot’s battery provides the necessary voltage to power its components.

PositionThe specific location or arrangement of an object in space. – The robot uses sensors to determine its position on the field.

FeedbackInformation sent back to a system to help control its operation or output. – The robot receives feedback from its sensors to adjust its movements accurately.

All Video Lessons

Login your account

Please login your account to get started.

Don't have an account?

Sign in

Register your account

Please sign up your account to get started.

Already have an account?

Sign up