Wireless Speed Monitoring DC Motor Using Radio Frequency

Abstract

The speed of the DC motor is directly proportional to the voltage applied across its terminals. Hence, if the voltage across motor  terminal is varied, then the speed can also be varied. This project uses the above principle to control the speed of the motor by varying the duty cycle of the pulse applied to it (popularly known as PWM control). At the transmitting end using push buttons, commands are sent to the receiver to control the  movement of the robot and make it move forward/backward besides incrementing and decrementing its speed. An RF transmitter acts as a remote control that has the advantage of adequate range (up to 200 meters) with proper antenna. The receiver decodes the commands before feeding it to another microcontroller to drive a DC motor via motor driver IC for necessary work. PWM (Pulse Width Modulation) is generated at the output by the microcontroller as per the program. The program can be written in Assembly language or in  Embedded C. The average voltage given or the average current flowing through the motor will change depending on the duty cycle (ON and OFF time of the pulses), so the speed of the motor will  change accordingly. The motor driver IC is interfaced to the microcontroller for receiving PWM signals and delivering desired output for speed control of the DC motor. Furthermore, the project can be enhanced by using power electronic devices such as IGBTs to achieve speed control higher capacity industrial motors.