Design of BLDC Motor Controller For an Impact Wrench:

Abstract

This thesis focuses on the design of a Brushless DC (BLDC) motor controller for use in an impact wrench. The main objective of this project is to create a working motor controller design independently, using basic electronic components and commonly available tools. Rather than aiming for high efficiency or advanced performance, the emphasis is placed on understanding the fundamental design process and building a functional prototype by hand. The system is built around the Arduino Uno microcontroller, which generates the required PWM signals for motor commutation. The IR2101 half-bridge gate driver is used to control the P75NF75 N-channel MOSFETs, which serve as the power switches for the three motor phases. The circuit also includes necessary passive components such as resistors and capacitors to support signal conditioning and circuit stability. The control strategy is sensorless, relying on the back electromotive force (back-EMF) generated by the motor to detect rotor position. The entire design process, including schematic development and component selection, was carried out manually to ensure a thorough understanding of the system architecture. This project demonstrates the basic steps involved in designing a simple BLDC motor controller. and serves as a learning experience in embedded systems, motor control, and circuit design