Remote Speed Control of DC Motor using DTMF Technology

Abstract

Direct current (DC) motor has already become an important drive configuration for many applications across a wide range of powers and speeds. The ease of control and excellent performance of the DC motors will ensure that the number of applications using them will continue to grow for the foreseeable future. This project is mainly concerned on remotely controlling the speed of DC motor using DTMF technology. DTMF technology has been used here as a means of acoustic communication for the control of speed of a DC motor by changing its voltage level from anywhere of this world via mobile network. It is a closed-loop real time control system, where optical encoder is coupled to the motor shaft to provide the feedback speed signal to controller. The desired signal for certain speed of the motor is remotely generated by Mobile phones, which is then sent to the Microcontroller through acoustic communication. The control algorithm in the microcontroller controls the speed of the motor at that desired value. Use of DTMF technology as an alternative for RF communication with the advantage of simplicity and audibility .Hence the system stands to be simple, rugged and cost effective. The experimental results show that the system has good linearity and repeatability.