Low Cost Versatile Timer Using Microcontroller

Abstract

This digital timer can be easily constructed using readily available IC’s and components. This timer can be used to automatically switch ON/OFF any electronic or electric equipment after a preprogrammed time period variable between a few seconds to 24 hours with high accuracy. This timer displays the timings on a digital readout display in the form of numeric LCD and can be set using a pair of push button switches. The programmed clock chip, PIC16F73, forms the heart of the circuit. The microcontroller has been programmed by embedded C language, LCD screen is connected to PORTB of the microcontroller IC. The high electronic equipment is connected through single pole relay component. The relay can be operated by microcontroller through transistor driver. When timer present time reached programed time value the microcontroller produce positive five volt to transistor driver, the transistor amplifies the five volt signal to 12 volt to relay, the relay drives the high voltage equipment like as pump motor, electric lamp etc. The project is very useful automatic industrial and domestic equipment. The advanced microcontroller is used for operates the overall operation. RISC microcontroller is used for this project.

Existing System

Proposed System

Architecture

BLOCK DIAGRAM