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Published2025-10-15
Introduction to SG90 Servo Motor
When it comes to compact yet powerful components in the world of electronics, the SG90 servo motor is a standout. Despite its small size, the SG90 is a versatile and efficient device, making it a favorite among hobbyists and engineers alike. Whether you're building a robotic arm or designing a model plane, understanding the working principle of the SG90 servo motor can help you unlock the potential of your project.
But what exactly is a servo motor, and how does the SG90 function so well in such a wide range of applications?
A servo motor is a specialized motor used for precise control of angular or linear position, velocity, and acceleration. Unlike regular motors that only provide continuous rotation, a servo motor can rotate to a specific angle and hold that position, which is why it's indispensable in robotics, automation, and other systems requiring precision.
There are many types of servo motors, ranging from large industrial ones to tiny models like the SG90. While larger servo motors are used in heavy machinery and industrial robots, the SG90 serves as an ideal solution for smaller, lighter applications.
The SG90: Small Yet Powerful
The SG90 is a miniature servo motor, often found in hobbyist kits for robotics and model airplanes. This motor is extremely lightweight, making it ideal for projects where size and weight are critical factors. Despite its compact form factor, the SG90 is incredibly effective in controlling small mechanical parts, providing precise movements with a high degree of accuracy.
Typically weighing only around 9 grams and measuring 22.2 x 11.8 x 31 mm in size, the SG90 is often used to control the movement of small arms, robotic legs, and even control surfaces in model planes. It is affordable and offers high precision for its size, making it a go-to choice for beginners and professionals alike.
The SG90 operates on a basic principle of rotational motion controlled by a system of gears, a DC motor, and a feedback mechanism. Here's a breakdown of the key components and how they work together to provide the precise control that servo motors are known for:
DC Motor: The heart of the SG90 is the small DC motor that drives the rotation. When current is supplied, the motor starts to turn, generating rotational movement.
Potentiometer (Feedback Control): A potentiometer is used to determine the motor's position. It acts as a feedback device, sending signals back to the controller, which adjusts the motor's position based on the desired angle.
Control Circuit: The control circuit receives signals, typically in the form of PWM (pulse width modulation), from a microcontroller or similar control system. These signals determine the angle at which the motor should stop. The SG90 uses these control signals to precisely adjust the position of the motor shaft.
Gears: Attached to the motor is a system of gears that translate the rotational motion of the motor into more controlled, precise movements. These gears help reduce the high-speed rotation of the motor into a slower, controlled movement suitable for the required application.
Motor Shaft: The final output of the servo is the rotation of the motor shaft, which is directly responsible for the movement of connected mechanical parts, such as a robotic arm or the rudder of a model airplane.
The Role of PWM (Pulse Width Modulation)
The SG90 servo motor is controlled using PWM, which is a method of varying the width of electrical pulses to control the angle of rotation. The duration of each pulse determines how far the servo rotates. For example:
A 1ms pulse might correspond to a 0-degree rotation.
A 1.5ms pulse could correspond to a 90-degree rotation.
A 2ms pulse may command a 180-degree rotation.
This method of control allows for precise adjustments to the angle, which is why the SG90 is ideal for projects requiring accurate movement.
Advantages of SG90 Servo Motor
Compact and Lightweight: Weighing only 9 grams, the SG90 is lightweight, making it suitable for lightweight robots and models.
High Precision: The servo motor provides high precision with an angular range of approximately 180 degrees, making it perfect for applications that require exact positioning.
Affordable: The SG90 is cost-effective, especially for hobbyists who want to build small, inexpensive robots or models without sacrificing performance.
Ease of Use: The SG90 is relatively simple to use, with only a small amount of external circuitry required for operation. This makes it ideal for beginners in the field of robotics.
Applications and Considerations for the SG90 Servo Motor
Now that we’ve covered the basics of how the SG90 servo motor works, it’s important to explore its practical applications. The versatility of the SG90 makes it a popular choice in a range of fields, from hobby projects to more complex robotic systems.
Common Applications of the SG90 Servo Motor
The SG90 is widely used in robotics, particularly in small and lightweight robots. Its precision makes it ideal for controlling robotic arms, grippers, and even legs. For instance, in a small hexapod robot, the SG90 can be used to control the movement of each leg, allowing the robot to walk or perform tasks with high accuracy. The affordability of the SG90 allows hobbyists to build functioning robots on a budget, which is one of the main reasons for its popularity in educational settings.
RC Models (Remote-Controlled Models)
The SG90 is also commonly used in remote-controlled models, such as airplanes, cars, and boats. It is particularly favored for controlling surfaces like ailerons, rudders, or elevators in model aircraft. In these applications, the small size and lightweight nature of the SG90 are essential, as they don’t add significant weight to the models while still providing the necessary movement and control.
In photography and videography, the SG90 can be used to stabilize cameras, especially in drone applications. By using servo motors to control the pitch and yaw of the camera, creators can achieve smooth, steady footage even in windy conditions or during rapid movements. The SG90 offers the precise control necessary for keeping a camera level and stable during flight.
The entertainment industry often uses animatronics for creating lifelike movements in figures and creatures. The SG90 servo motor is perfect for animatronic projects, as it can control the movement of facial features, eyes, or limbs. Its small size allows it to be easily integrated into tight spaces, while the motor's precision ensures that each movement looks smooth and realistic.
While the SG90 might not be suited for large-scale industrial applications, it can be employed in smaller automation tasks, such as controlling small valves or actuators in laboratory setups or prototype systems. The motor’s efficiency and accuracy make it a valuable asset in prototypes or low-power, low-cost automation systems.
Limitations of the SG90 Servo Motor
While the SG90 offers numerous benefits, it’s not without its limitations. Understanding these constraints can help in deciding where the SG90 is best suited and where a different type of servo motor may be required.
Limited Torque: The SG90 is relatively weak in terms of torque, with a maximum torque of around 1.8 kg/cm. This means it is not suitable for applications that require handling heavy loads or high-stress operations.
Limited Range of Motion: While the SG90 offers a good range of 180 degrees, it is not as versatile as other motors in terms of continuous rotation. Applications requiring full rotation (e.g., for a rotating platform) might need a different type of motor.
Temperature Sensitivity: Like most small motors, the SG90 can be sensitive to extreme temperatures. Operating it outside of its specified temperature range could result in decreased performance or potential damage.
The SG90 servo motor may be small in size, but its wide range of applications and reliable performance make it a favorite in the world of electronics. Whether you are building robots, remote-controlled models, or even animatronics, the SG90 can help you achieve precise, controlled movements with minimal effort. Its ease of use, affordability, and versatility make it a perfect choice for beginners and professionals alike.
As technology continues to advance, the applications of small components like the SG90 will only expand, offering even more possibilities for innovation in robotics, automation, and beyond.
Kpower has delivered professional drive system solutions to over 500 enterprise clients globally with products covering various fields such as Smart Home Systems, Automatic Electronics, Robotics, Precision Agriculture, Drones, and Industrial Automation.
Update：2025-10-15
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