Under the Supervision Of Md. Ashraful Islam Jewel Lecturer, Department of CSE Submitted by Md. Mahfuzur Rahman 201130496 Dept. of Computer Science and Engineering Asian University of Bangladesh
Under the SupervisionOf
Md. Ashraful Islam JewelLecturer, Department of CSE
Submitted
byMd. Mahfuzur Rahman 201130496
Dept. of Computer Science and EngineeringAsian University of Bangladesh
Reducing the wastage of power
Reducing physical efforts Improve the system in our daily life
simple and powerful device, which uses Transistor (BC547 NPN)
switches ON lights (LED) when the light (i.e. day light) decreases
switches OFF lights when light falls on LDR
Transistor BC547
LDR (Light Dependence Resistor)
Resistor
LED
Transistor BC547: has an emitter terminal, a base terminal
and a collector terminal current flowing from the base to the
emitter controls the collector current
LDR an electronic component whose resistance
decreases with increasing incident light intensity used in a potential divider setup with a second
regular resistorResistor resist the flow of current across the resistor device adjustable resistors are refers to as potentiometers
Light falls on LDR, it shows its minimum resistance and voltage drops across LDR less than VBE of Transistor Q1.
So, no current will go from the collector to the emitter and transistor remains turn off.
No light falls on LDR, it shows its maximum resistance and voltage drops across LDR greater than VBE of Transistor Q1.
Now the transistor enters into ON state and at the output side Ic current will flow through the LED. So, the LED is ON
Energy savings
Low cost
Safety and Security
Reducing physical efforts
It has a limitation of power
Light turns on when shadow falls on LDR
LED is a low voltage device
By using same concept we can modify this project for commercial use
It is possible to make the project
appropriate for high voltage of power
Question ?