2B-AUTOMATIC GARAGE LIGHT WITH MUSIC and AUTO-OFF
While parking vehicles in the garage in the darkness many people need extra source of light as it is difficult to trace the switch in the dark. Keeping these points in view, this project has been developed . With the help of this project you can park your vehicle easily, that too with a pleasent musical tone.
TECHNICAL DESCRIPTION AND WORKING
This project has been developed and tested O.K. in our TV Engineers Technical Lab. The components and PCB used in the projects published in our books are available for sale at resonable price.
The Timer IC 555 is employed in this project. A +9 volt supply is fed to its pin no 8 and reset pin no 4. The working of the project depends on the LDR . When the light from the headlight of your car falls on the LDR, the resistance of the LDR decreases resulting low state information at trigger pin no 2 of the IC 555. The inverter amplifier internally connected to output pin no. 3 of the IC assumes high state. As a result the transistor BC148 conducts and energises the relay. When the relay becomes ON, the bulb inside the garage glows and as the IC receives proper bias, the speaker connected to the IC produces pleasent musical tone. In the mean time , the capacitor connected to pin no. 7 becomes charged. This charge of the capacitor maintains the light ON for some time even after the Head lights are OFF.
PRECAUTIONS WHILE ASSEMBLING THE PROJECT:-
*Check polarity of diode and capacitor while assembling.
*Keep LDR in such place so that the light of Head-light falls directly on LDR.
*Use IC base for mounting of IC 555.
*First of all check all the components as per circuit.
*While mounting transistor, you should connect collector , base & emitter properly.
IC 555 = 1
BC148 = 2
IC UM66 = 1
RELAY 9V = 1
47K = 1
100E = 1
470E = 1
4.7K = 1
1M = 1
100K = 1
470MFD/25V = 1
.01 = 1
3.1V = 1
DIODE IN4007 = 1
LDR = 1