ESC electronic speed controller with arduino ALL EXPLAINED

Summary

The video provides a detailed explanation of how to build an electronic speed controller (ESC) for brushless motors. It covers the fundamentals of brushless DC motors, which have three input wires and require precise switching of voltages to maintain motor rotation. The creator explains the complex synchronization process, utilizing back electromotive force detection for optimal switching. With components like a microcontroller, MOSFET transistors, and drivers, the project is designed to control motor speed efficiently. The tutorial includes circuit design, code development, and real-time testing, making it a comprehensive guide for enthusiasts interested in DIY electronics.

Takeaways

• ⚙️ Building an electronic speed controller (ESC) for brushless motors is complex but achievable with the right understanding.
• 💡 Brushless motors differ from regular DC motors by having a triple-phase input, requiring specific voltage switching to operate.
• 🔄 To keep a brushless motor spinning, the polarity of its three inputs must be switched in a precise sequence, controlled electronically.
• ⚡ Back electromotive force (back EMF) is crucial for detecting the right moment to switch the motor's input states.
• 🧲 Faraday's law of electromagnetic induction is used to detect magnetic flux changes, which help determine the rotor's position.
• 🔌 An electronic speed controller uses MOSFET transistors to switch between high and low states for the motor’s inputs, allowing for high-current flow.
• 🖥️ The Arduino microcontroller is used to read voltage drops, manage input states, and control the motor's rotation speed.
• 🔧 Additional components like MOSFET drivers, capacitors, and voltage regulators are required for building the ESC circuit.
• 📊 The switching speed of the motor is controlled by adjusting the timing of the input sequence, which is influenced by the rotor's position.
• 🎛️ The ESC design includes features to manually control the motor speed using a potentiometer or code to adjust the timing of the switches.

Q & A

What is a brushless motor and how does it differ from a normal DC motor?

A brushless motor is a type of DC motor that has three wires for input (compared to the two wires of a normal DC motor), requiring a more complex switching sequence to operate. Unlike a normal DC motor, which switches voltage polarity mechanically through brushes, a brushless motor relies on an electronic device to switch the polarity of its inputs.

Why can't we apply a normal differential voltage to a brushless motor?

Brushless motors have three-phase inputs, so a simple two-wire differential voltage, like in a normal DC motor, is insufficient. Instead, a specific sequence of switching voltage to each of the three wires is needed to maintain rotation, making it more complex to control.

How does a brushless motor spin and what sequence is needed for proper operation?

To spin, the brushless motor requires switching between high, low, and free states of its three inputs (A, B, and C) in a specific sequence. By alternating the input states, magnetic fields are created and changed, which in turn pushes or pulls the rotor's magnets, making the motor spin.

What is the purpose of an Electronic Speed Controller (ESC) in the operation of a brushless motor?

The ESC is responsible for controlling the switching of inputs to the motor, ensuring that the right voltage is applied at the right time to each input. It also synchronizes the motor’s rotation with the switching sequence, which is essential to keep the motor running smoothly.

Why is it necessary to synchronize the switching sequence with the rotor's position in a brushless motor?

Synchronization is critical because switching the inputs too early or too late can cause the motor to stop or rotate in the wrong direction. To maintain continuous motion, the ESC must switch the input voltages at the exact right moment relative to the rotor's position.

What role does electromagnetic induction play in determining the switching point of the motor?

Electromagnetic induction generates a voltage drop (back electromotive force) in the coil when the rotor moves past a coil. By measuring the induced voltage in the free (non-energized) input wire, the ESC can detect when the rotor is in the optimal position to switch to the next state, ensuring smooth motor rotation.

What is 'zero crossing' and how is it used in controlling a brushless motor?

'Zero crossing' refers to the point where the back electromotive force crosses zero voltage. This happens when the magnetic field inside the coil reaches a peak. By detecting this point, the ESC can accurately determine when to switch inputs and continue the motor's rotation.

What components are needed to build an Electronic Speed Controller (ESC)?

An ESC typically consists of a microcontroller (like an Arduino Nano), MOSFET transistors for switching, MOSFET drivers, capacitors, resistors, and voltage regulators. The MOSFETs handle high currents from the motor, while the microcontroller directs the switching of inputs.

Why are MOSFET drivers used in the ESC circuit?

MOSFET drivers are used because the microcontroller cannot supply enough voltage or current to the MOSFETs directly. The drivers take the low-voltage signal from the microcontroller and output a higher voltage to properly control the MOSFETs, which switch the high currents needed by the motor.

How does the potentiometer affect the motor speed in this ESC design?

The potentiometer is used to adjust the delay between switching events in the sequence, effectively controlling the motor speed. A shorter delay results in faster switching, which makes the motor spin faster, while a longer delay slows the motor down.