RPM Measurement of Motor Using OPTO Isolator

Abstract

This project is developed for the users to detect and count the speed of a motor and to control it. This project mainly consists of a slot sensor, motor, microcontroller unit and LCD display. A disc is connected with the motor. A hole is made at the edge of the disc. An IR LED and photo diode are connected at the two sides of the hole focusing the IR LED towards the photo diode. When the motor is rotated, the disc is rotated along with the motor and the IR rays passes through the whole when one cycle is completed. The sensor senses and sends signal to the microcontroller. The microcontroller sends signal to the counter. The counter calculates the number of rotations per minute. If the speed exceeds or lags a particular limit, the microcontroller automatically switches off the motor through driver section and relay. The LCD display displays the speed of the motor. This project is very useful in industries. Since microcontroller is used, the operations are very accurate. This project is very cheap and cost effective. The microcontroller program is written in assembly language. The microcontroller used is PIC16F73.

Existing System

Proposed System

Architecture

BLOCK DIAGRAM