PC based DC motor speed control

The purpose of this study is in electronic scope to design a DC speed controller circuit controlled by computer as a GUI (Graphical User Interface) from minimum to maximum speed. This project is focus on the DC motor speed control by varying the duty cycle of Pulse With Modulation (PWM) signal via Computer (PC). Nowadays, the computers are widely used in daily applications as a graphical user interface (GUI) because it is easy to monitoring, save cost and time. In this project, PC used to generate PWM signals assisted by Microsoft Visual Basics software thus reduced hardware implementation in a system. PWM speed control is desirable due to its high power efficiency compare with another method of speed control like frequency control, current and voltage control. The motor averages the input duty cycle into a constant speed which is directly proportional to the percent duty cycle. The Software send PWM signal to the driver circuit through the RS232 serial port. The driver circuit will boosted the PWM signal to drive the MOSFET and thus control the motor. The speed of DC motor is depending on the spectrum of PWM that refer to their duty cycle. This project was able to control the motor speed via PC from zero to maximum speed which is most important feature in industrials control applications