Light Switch

[[wysiwyg_imageupload:1934:]]Project is done by Vivek Vadodariya & Megh V Patel. They are students of G.H.Patel College of Engineering & Technology(GCET).

Circuit components:

Resistors- R3=10k Ohm

R4=100k Ohm

Potentiometer- R1=4kOhm

LDR

U1A & U2B- IC LM358N (both are on single IC)

U3- IC 4017 Decade Counter

Relay- 12V DC

12V Supply

Circuit Description:

When light fall on LDR it allows a voltage signal through non inverting terminal of the IC LM358N. We have given another voltage signal to inverting terminal of IC LM358N through potentiometer. By setting potentiometer as per the light we get an output from the IC LM358N and it is given to IC 4017 decade counter clock. We have given reset to out2 of IC 4017. Thus it counts only 0 & 1 out. We have amplified signal from out 1 of IC 4017 through IC LM358N. And this amplified signal is given to relay coil. So it switch on or off as per the signal.

Notes:

(1) We can set this switch for different lights by setting only potentiometer.

(2) You can use 9V supply. The only change needed is relay.

(3) You can use this switch for any switch purpose. Here it is shown bulb switch. But it can be use as robot switch or etc for technical events.