Easier Approach to Electronic Projects

Simple Light Sensor using 741 Op-amp


This is a Light sensor circuit. Probably most simple and interesting circuit to play with. It can be configured as either shadow detector or Light detector, which means it can detect the intensity of light.

Right now in the circuit diagram it is configured as a Shadow Detector, that means the LED will turn on when we show a bright light over LDR.

We can change this circuit as Light Detector by simply swapping the pins 2 & 3 of 741 Comparator IC, and then LED will turn on when LDR is dark.

In this circuit, please make sure that pins no 1,5 & 8 are not connected and left idle.

Pin 6 is output pin. In the circuit it is connected to an LED via 1K resistor, but you can also connect a transistor to turn on a relay, motor or any other output.

 

Parts Required & Circuit Diagram:

  1. 10k potentiometer, 10k & 1k
  2. LDR
  3. 741 Comparator op-amp
  4. LED
  5. 9V battery

 




 

Bread board Arrangement:

      

Strip Board version:

%d bloggers like this:
Read more:
3D Printing Technologies | Types of 3D Printing

All 3D printing technologies create three-dimensional physical objects layer by layer from digital designs from many sorts of materials like...

avrdude Error

This is a very common error found in Arduino Enviroment,  avrdude: stk500_getsync(): not in sync: resp = 0x00 avrdude: stk500_disable():...

Resistor Color Code

This video is on how to read Resistor Color Code Resistor Color Code Web Application Resistance: Ω Tolerance: ± %...

Close