ClassX Video Lessons Youtube Channel The Engineering Mindset Brushless Motor – How they work BLDC ESC PWM
Brushless motors are fascinating devices that are widely used in various applications, from drones to computer fans. In this article, we’ll explore how these motors work and how you can control one using an Arduino. Let’s dive in!
A brushless motor, often referred to as a BLDC motor, is a type of motor that converts electrical energy into mechanical energy. This mechanical energy is used to create motion, such as spinning the blades of a drone to generate lift. You’ll also find brushless motors in devices like PC cooling fans, CD drives, and battery-powered drills.
Both brushless and standard DC motors have magnets and coils of wire. However, standard DC motors use brushes—carbon blocks that make contact with commutator plates to allow electricity to flow through the coils. This contact creates friction, which can wear down the brushes over time, requiring maintenance.
Brushless motors, on the other hand, eliminate the need for brushes. In these motors, the outer casing rotates while the coils remain stationary. This design reduces friction, increases efficiency, and extends the motor’s lifespan. Most brushless motors are “outrunner” types, where the rotor spins outside the motor, providing more torque.
Unlike standard DC motors that have two wires, brushless motors have three wires connected to an electronic speed controller (ESC). The ESC receives signals from a main controller using pulse width modulation (PWM) to adjust the motor’s speed by controlling the current flow through the wires.
The motor’s base has three wires, usually color-coded to represent different phases, and features threaded holes for mounting. The shaft runs through the motor, allowing attachments to utilize the rotation. Both the rotor and stator have holes for venting heat generated by the coils, preventing overheating.
Inside the stator, the shaft passes through bearings for smooth rotation. The stator has 12 teeth made of laminated metal sheets to reduce energy-wasting eddy currents. The 12 coils of wire are grouped into three sets, using enameled wire for insulation.
The ESC connects to the coils, providing electrical current. The coils are wrapped in opposite directions, creating a delta connection, the most common wiring method for brushless motors. Inside the rotor, high-strength permanent magnets are arranged with alternating polarity, allowing for continuous rotation.
To control a brushless motor, the ESC receives a PWM signal, adjusting the motor’s speed. The ESC uses MOSFETs as electronic switches to manage current flow and monitors the coils for back EMF to determine the rotor’s position.
Let’s build a simple circuit to control a brushless motor using an Arduino and a potentiometer. You’ll need an Arduino, a brushless motor, an ESC, a power supply, and some wires. Connect the motor to the ESC, then connect the signal wire to port 9 on the Arduino to send a PWM signal to the ESC.
Next, connect the power supply to both the ESC and the Arduino. Connect the potentiometer to the circuit, with the left side to the positive rail, the right side to the negative rail, and the center pin to port A0 on the Arduino.
Now, let’s write the program. Use the servo library to create an object called ESC, which will send a PWM signal from pin 9. The pulses will range from 1 to 2 milliseconds in length. The code will read the voltage from the potentiometer and convert it into a scale that the servo library can understand.
After uploading the code, disconnect the USB cable and connect the power supply to the ESC. The motor will beep as it configures itself, and you can control the speed using the potentiometer.
Continue exploring the world of electronics engineering by checking out more resources and videos. Happy learning!
Gather the necessary components: an Arduino, a brushless motor, an ESC, a power supply, and some wires. Follow the instructions to connect the motor to the ESC and the ESC to the Arduino. Use a potentiometer to control the motor speed. This hands-on activity will help you understand the physical setup and connections required to control a brushless motor.
Write a program using the Arduino IDE to control the brushless motor’s speed with a potentiometer. Use the servo library to send PWM signals to the ESC. Experiment with different PWM values and observe how they affect the motor’s speed. This activity will enhance your programming skills and deepen your understanding of PWM control.
Research the differences between brushless and standard DC motors. Prepare a short presentation highlighting the advantages and disadvantages of each type. Focus on aspects such as efficiency, lifespan, and applications. Present your findings to the class to improve your research and public speaking skills.
Investigate various applications of brushless motors in everyday devices. Create a list of at least five devices that use brushless motors and explain why they are preferred over standard DC motors in these applications. Share your findings with the class to broaden your understanding of real-world applications.
Design an experiment to test the efficiency of a brushless motor compared to a standard DC motor. Consider factors such as power consumption, heat generation, and torque. Conduct the experiment, record your observations, and analyze the results. This activity will help you apply scientific methods to evaluate motor performance.
Here’s a sanitized version of the provided YouTube transcript, with unnecessary filler words and informal language removed for clarity:
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This is a brushless motor, often used for creating lift, and it uses three-phase electricity. In this video, I will show you how they work and how to control one with an Arduino.
A brushless DC motor looks like this. They come in various sizes and designs, but they all convert electrical energy into mechanical energy. We can use that mechanical rotation, for example, in a drone to spin the blades and create lift. Brushless motors are also found in PC cooling fans, CD drives, and battery-powered drills.
When comparing brushless motors to standard DC motors, both have magnets in the outer casing and coils of wire at the center. However, standard DC motors have brushes at the rear, which are carbon blocks that rub against commutator plates to allow electricity to flow through the coils while rotating. The gaps in the commutator plates cause the coils to energize and de-energize in a specific order to create rotation. Over time, the brushes wear down due to friction, requiring repair or replacement.
In contrast, brushless motors have no brushes. In this design, the outer casing rotates while the coils remain stationary, resulting in less friction, greater efficiency, and a longer lifespan. Most applications use outrunner motors, where the rotor turns outside the motor, as they provide more torque.
A standard DC motor has two wires and rotates when connected to an electrical supply. A brushless motor has three wires that connect to an electronic speed controller. A main controller sends signals using pulse width modulation to the speed controller, which adjusts the motor’s speed by controlling the current flow through the three wires.
The base of the brushless motor has three wires, usually colored differently to represent the different phases. It also has threaded holes for mounting and a clip to hold the shaft in position. The shaft runs the length of the motor and extends out the front, allowing for attachments to utilize the rotation. The rotor and stator both have holes for venting heat generated by the coils, preventing damage from overheating.
Inside the stator, the shaft passes through bearings for smooth rotation. There are 12 teeth on the stator made of laminated sheets of metal, which are electrically isolated to reduce eddy currents that waste energy. The stator has 12 coils of wire grouped into three sets, with enameled wire for electrical insulation.
The speed controller connects to the coils to provide electrical current. In this design, adjoining coils are wrapped in opposite directions, creating a delta connection, which is the most common wiring method for brushless motors.
Inside the rotor, high-strength permanent magnets are arranged with alternating polarity. This design, with 14 magnets and 12 stator coils, prevents alignment, allowing for continuous rotation.
To control the motor, the speed controller receives a pulse width modulation signal, which adjusts the motor’s speed. The controller uses MOSFETs as electronic switches to manage current flow. The speed controller monitors the coils for back EMF, which helps determine the rotor’s position.
Now, let’s build a circuit to control a brushless motor with an Arduino and a potentiometer. We need an Arduino, a brushless motor, a speed controller, a power supply, and some wires. Connect the brushless motor to the speed controller, then connect the signal wire to port 9 of the Arduino. This will send a pulse width modulation signal to the speed controller.
Next, connect the power supply to the speed controller and the Arduino. Connect the potentiometer to the circuit, linking the left side to the positive rail, the right side to the negative rail, and the center pin to port A0 of the Arduino.
Now, let’s write the program. The code will use the servo library to create an object called ESC, which will send a pulse width modulation signal out of pin 9. The pulses will range from 1 to 2 milliseconds in length. The code will read the voltage from the potentiometer and convert it into a scale that the servo library can understand.
After uploading the code, disconnect the USB cable and connect the power supply to the speed controller. The motor will beep as it configures itself, and you can then control the speed using the potentiometer.
Check out one of the videos on screen now to continue learning about electronics engineering.
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This version maintains the essential information while improving readability and clarity.
Brushless – A type of electric motor that operates without brushes, using electronic commutation to control the motor’s speed and torque. – Brushless motors are preferred in drones due to their high efficiency and low maintenance requirements.
Motor – A device that converts electrical energy into mechanical energy to perform work. – The electric motor in the robot allows it to move with precision and speed.
Arduino – An open-source electronics platform based on easy-to-use hardware and software, often used for building digital devices and interactive objects. – Students used an Arduino to program the automated watering system for their engineering project.
Efficiency – The ratio of useful output energy to the total input energy, often expressed as a percentage, indicating how well a system converts energy. – Improving the efficiency of the solar panel system was crucial to maximizing energy output.
PWM – Pulse Width Modulation, a technique used to control the amount of power delivered to an electrical device by varying the width of the pulses in a pulse train. – PWM is commonly used in motor speed controllers to adjust the speed of a DC motor.
Coils – Wire wound into a series of loops, often used in electrical devices to create magnetic fields or inductance. – The coils in the transformer are designed to step down the voltage for safe usage in household appliances.
Torque – A measure of the rotational force applied to an object, often used to describe the performance of motors. – The new electric car boasts high torque, allowing it to accelerate quickly from a standstill.
Controller – A device or set of devices that manages, commands, or regulates the behavior of other devices or systems. – The temperature controller in the HVAC system ensures the building maintains a comfortable climate.
Electronics – The branch of physics and technology concerned with the design and application of circuits and devices using transistors, microchips, and other components. – Understanding the basics of electronics is essential for designing and building modern gadgets.
Circuit – A closed path through which an electric current flows or may flow. – The students built a simple circuit to light up an LED as part of their introductory electronics class.
