With the advancement of technology, today automation and security to the person or property has become a part of mans life. The present project work introduces the concept of automatic control of household electrical gadgets, for this purpose two important features are selected (a) Automatic control of outdoor Lights (b) Automatic control of Overhead tank. In addition to these two features, for the home security purpose an intruder alarm is also designed in this project work.
The overall system is designed with microcontroller to make the system more effective and efficient. Utilization of Microcontrollers in the field of automation is gaining popularity for several reasons including price, programmability and performance specifications offered. Software development, rather that hardware development, increasingly dominates new product design cycles. Therefore, one of the most common reasons why system designers are increasingly choosing microcontrollers and its architecture is for its rich and cost effective software.
Automatic control of outdoor lights
This circuit is used to energize the outdoor lights such as portico lights, Main gate lights, Corridor Lights terrace lights, etc, automatically, whenever the natural light disappears i.e., darkness prevails. Similarly the same lights de-energizes automatically whenever natural light appears. For this purpose an LDR (Light Dependent resistor) is used as a light-sensing device. LDR is a kind of transducer which converts the light intensity into variable resistor. The output of the LDR is fed to the A/D converter for converting the analog signal produced by the LDR according to the light intensity into digital pulses. The output of the A/D converter is fed to the microcontroller, such that the controller energizes the outdoors lights through the Relay contact, whenever the natural light disappears. Similarly whenever the natural light appears, these outdoors lights de-energizes automatically.
Automatic Control of Over head Tank1
This feature makes the continuous monitoring of water level in Overhead water tank. This circuit is designed such that the water pumping Motor energizes automatically and feeds water in the overhead water tank, when the level in water tank becomes low and de-energizes the motor when the water level reaches more than 90% of the water tank. For this purpose for sensing the water level continuously Copper electrodes are used. Normally the low level is adjusted to 20% of the capacity of the tank and the high level is adjusted to 90% of the capacity of the tank. The output of the electrodes is fed to the microcontroller and the controller energizes or de-energizes the pumping motor relay automatically.
The intruder alarm circuit is designed with IR sensors, for this purpose two IR sensors are used and both the sensors are arranged parallel to each other at the main hall of the house. The main purpose of these sensors is to detect the presence of a person who is inside the locked house. The IR signal delivered from one sensor is detected by the another sensor, as long as the detector receives the signal from the IR signal generator the output of the controller remains zero, whenever any person passes between these two sensors, then the IR beam will be interrupted momentarily, by which the controller energizes the alarm automatically