Automatic Street Light Using IC-555 HD

Abstract:- This project aims at designing and executing the advanced development in embedded systems for energy saving of street lights with light depending resistor. Nowadays, human has become too busy and he is unable to find time even to switch the lights wherever not necessary. This can be seen more effectively in the case of street lights. The present system is like, the street lights will be switched on in the evening before the sun sets and they are switched off the next day morning after there is sufficient light on the roads. But the actual timings for these street lights to be switched on are when there is absolute darkness. With this, the power will be wasted up to some extent. This project gives the best solution for electrical power wastage. Also the manual operation of the lighting system is completely eliminated. In our project we are using LDR, which varies according to the amount of light falling on its surface, this give an indication for us whether it is a day/night time. Needs no manual operation for switching ON and OFF. When there is need of light. It detects itself weather there is need for light or not. When darkness rises to a certain value then automatically street light is switched ON and when there is other source of light i.e. day time, the street light gets OFF. The sensitiveness of the street light can also be adjusted. In our project we useL.E.D for indication of bulb. Component used 9v Battery with strip Switch Resistor of 470 Ohms L.D.R (Light Depending Resistance) I.C-555 with Base L.E.D (Light Emitting Diode). Variable Resistance of 50 Kilo ohms P.C.B (Printed Circuit Board of 555 or Vero board). WORKING: When light falls on the LDR then its resistance decreases which results in increase of the voltage at pin 2 of the IC 555. IC 555 has got comparator inbuilt, which compares between the input voltage from pin2 and 1/3rd of the power supply voltage. When input falls below 1/3rd then output is set high otherwise it is set low. Since in brightness, input voltage rises so we obtain no positive voltage at output of pin 3 to drive relay or LED, besides in poor light condition we get output to energize. Precautions: a) LDR used should be sensitive. Before using in the circuit it should be tested with multimeter. b) I.C should not be heated too much while soldering, can destroy the I.C. For safety and easy to replace, use of I.C base is suggested. While placing the I.C pin no 1 should be made sure at right hole. c) Opposite polarity of battery can destroy I.C so please check the polarity before switching ON the circuit. One should use diode in series with switch for safety since diode allows flowing current in one direction only. d) L.E.D glows in forward bias only so incorrect polarity of L.E.D will not glow. Out put voltage of our project is 7.3 volt therefore 4 LED in series can be easily used with out resistance. e) Each component should be soldered neat and clean. We should check for any dry soldered. f) LDR