“I’ve been trying to make a good ESC for years. My first prototype 3 years ago was working “good”. It was very big and the BEMF was not that good. It could reach decent speeds and you ahve that tutorial here on this page. Now, with my final version I have all taht I wanted. High speed, good BEMF detection and that means good torque, PWM control of the speed and small size. The board is programed in Arduino.
So what is an ESC? Well, electronic speed controllers are used to control brushless motors, in thisc ase the motor has a triple phase input. To control this input, the ESC must apply a special sequence of LOWs and HIGHs signals in a predefined order. It has to conmutate very fast and by taht rotate the rotor of the motor. In this tutorial we will see how to control the rotation, the speed, detect the BEMF and by that know when to make the switch to the next step of the sequence. So this is a sensorless brushless motor speed controller since it uses no sensor to detect the rotor position. We will learn:
- The schematic and why we need each part
- Triple phase MOSFET bridge control
- BEMF detection and 0 cross
- Interrumprions and internal comparator of ATMEGA328
- PWM control”