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Published2025-10-15
What is the SG90 Servo Motor and How Does it Work?
The SG90 servo motor is a small, lightweight, and versatile DC motor that is often used in electronics and robotics projects. It is particularly popular among hobbyists due to its affordability, ease of use, and reliability. While many servo motors are designed for high-torque industrial applications, the SG90 is built for lighter, smaller tasks, making it a go-to component for DIY projects, educational robots, and remote-control vehicles.
Understanding the SG90 Servo Motor: Key Components
At the heart of every SG90 servo motor is a small DC motor, along with an internal controller that helps convert the electrical input into precise mechanical motion. Unlike standard DC motors, which rotate continuously, a servo motor is designed for precise rotational movements, typically within a range of 0 to 180 degrees. This precise motion is controlled by sending PWM (Pulse Width Modulation) signals to the motor, which then determines the angle of rotation.
Here are the key components that make the SG90 servo motor work:
DC Motor: The DC motor generates rotational movement when electrical current is applied.
Gearbox: The motor's gears reduce the high-speed rotation of the DC motor into slower, controlled rotations, allowing for more precise movements.
Control Circuit: The onboard control circuit receives the PWM signals and adjusts the motor’s position accordingly.
Feedback Mechanism: Most servo motors, including the SG90, come with a built-in potentiometer that sends feedback to the control circuit, allowing it to maintain the desired position.
How the SG90 Servo Motor Works
When a PWM signal is sent to the servo motor, it specifies the position to which the motor should move. The duration of the pulse within the PWM signal determines the angle of rotation. For example, a short pulse might command the motor to rotate to one extreme, while a longer pulse might move it to the opposite extreme.
To break it down further:
PWM Signal: This is a digital signal that alternates between ON and OFF states. The pulse duration (high time) within each cycle defines the position of the servo.
Control Circuit: The servo motor’s control circuit processes the PWM signal and drives the motor to rotate accordingly.
Potentiometer Feedback: The motor's position is continuously monitored by the potentiometer, which ensures that the motor stays at the correct angle as commanded by the PWM signal.
In terms of practical application, a standard SG90 servo can move between 0 to 180 degrees with 1 microsecond pulse width representing 0 degrees and 2 milliseconds corresponding to 180 degrees. This fine control is what makes the SG90 ideal for precise positioning tasks, such as steering, camera pan-and-tilt, or controlling robotic arms.
Advantages of Using the SG90 Servo Motor
Compact and Lightweight: The SG90 is small and light, making it perfect for use in small-scale projects like drones or mini-robots.
Affordable: The SG90 offers excellent performance at a budget-friendly price, which is great for hobbyists and beginners who want to learn about robotics without breaking the bank.
Easy to Control: With simple PWM signals, controlling an SG90 servo motor is straightforward and can be done with microcontrollers like Arduino or Raspberry Pi, making it ideal for educational purposes.
High Precision: The built-in feedback loop ensures that the motor maintains precise control, making it reliable for tasks that require accuracy.
Practical Applications and Setup of the SG90 Servo Motor
Applications of the SG90 Servo Motor
While the SG90 servo motor is relatively small and not suited for heavy-duty tasks, it is perfect for a wide range of applications in robotics and automation. Below are some of the most common uses for this motor:
Robotics: One of the most popular applications for the SG90 is in robotic systems. Due to its small size, it’s ideal for building robots with moving parts, like arms, legs, or rotating platforms. Whether you’re making a robot for educational purposes or a more complex autonomous robot, the SG90 serves as a reliable motor for precise movement.
RC Vehicles: The SG90 is also commonly used in remote-controlled vehicles, particularly for steering and control. It’s ideal for lightweight cars, boats, or aircraft where the control of movement is necessary, but the weight and space constraints make larger motors impractical.
Camera Gimbals and Pan-Tilt Mechanisms: Many camera gimbal systems rely on servo motors to achieve smooth panning and tilting. The SG90 is often used in these types of applications where small and precise movements are required for capturing stable footage.
Mechanical Claws and Grippers: If you’re building a robotic arm or claw, the SG90 is the perfect choice for controlling the opening and closing of the grippers. Its accuracy allows for delicate handling of objects.
Educational Projects: Because the SG90 is easy to control and affordable, it’s widely used in educational settings to teach students about robotics, electronics, and programming. It's the ideal introductory motor for those starting out in the field of electronics.
Setting Up the SG90 Servo Motor
Setting up an SG90 servo motor is relatively simple, especially when using a platform like Arduino or Raspberry Pi. Below is a basic step-by-step guide for setting up the SG90 with an Arduino:
Arduino (e.g., Arduino Uno)
Power Supply (usually 5V)
Connecting the Servo Motor:
Red Wire (VCC): Connect this to the 5V pin on your Arduino.
Brown Wire (GND): Connect this to the GND pin on your Arduino.
Yellow or Orange Wire (Signal): Connect this to one of the digital pins (e.g., Pin 9) on your Arduino for PWM control.
To control the servo, you will need to use the Servo library in Arduino. Here's a simple code snippet to get the servo moving:
Servo myServo; // create a servo object to control the servo
myServo.attach(9); // Attach the servo to pin 9
myServo.write(0); // Move the servo to 0 degrees
delay(1000); // Wait for a second
myServo.write(90); // Move the servo to 90 degrees
delay(1000); // Wait for a second
myServo.write(180); // Move the servo to 180 degrees
delay(1000); // Wait for a second
After uploading the code, your servo motor should begin rotating between 0, 90, and 180 degrees in a loop. You can adjust the angles and delays to fine-tune the servo's movement.
Servo Not Moving: If the servo doesn’t move, check your connections and make sure the power supply is adequate. The SG90 typically operates at 5V, but if the voltage is too low, it may not function properly.
Servo Overheating: If the servo motor overheats, it could be a sign that it’s being overdriven (too much load or power). Make sure the servo is not under heavy stress for extended periods, and ensure it’s operating within its recommended parameters.
Incorrect Movement: If the servo isn’t moving to the correct angles, ensure that the PWM signal is properly calibrated. Adjusting the PWM values in the code can correct the positioning.
The SG90 servo motor is a powerful yet affordable tool for a wide variety of applications. Its precise control, small form factor, and ease of use make it an essential component in robotics, remote-controlled vehicles, and educational projects. Whether you’re a hobbyist just starting with electronics or an experienced engineer working on more complex systems, the SG90 offers a versatile solution for controlling movement in a variety of creative ways.
Established in 2005, Kpower has been dedicated to a professional compact motion unit manufacturer, headquartered in Dongguan, Guangdong Province, China.
Update：2025-10-15
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