Robo India in this tutorial explains how to use Operational Amplifier (Op Amp) as comparator. In this tutorial LM358 IC is used. It has got 2 comparator.
1. Introduction:
Operational Amplifier (Op-Amp) can be used as comparator. This tutorial explains how to use use LM358 Op Amp as comparator. LM358 has got dual comparator. Only one of them is used here in this tutorial. You may use both as an exercise.
Download Data Sheet of LM358 here.
1.2 List of parts
Following parts will be used to perform this circuit.
| S.No. | Item | Quantity |
| 1. | Basics of Electronics Kit’s Platform(Without Transformer) | 1 |
| 2. | 9V Battery with connector | 1 |
| 3. | Indicator LED | 1 |
| 4. | 1 K Resistance | 1 |
| 5. | Jumper Wires male to male | 6 |
| 6. | 10K Potentio meter | 1 |
| 7. | LM358 | 1 |
| 8. | 4.7K Resistance | 2 |
2. Circuit
VCC and GND is supplied to the IC on pin No. 8 and 4 respectively. Other than these two inputs, Inputs have been given on Pin 3 and Pin 4. Input voltage on Pin No. 3 is fix and that will be half of the batter voltage. On Pin no. 2 variable input is given through 10K Pot. This IC will compare both inputs and will give digital output on Pin1. That out will be high till Voltage on Pin 2 is less than voltage on Pin 3 and low for vice versa.
Same arrangement can be made on Pin 5, 6, and 7. The out put taken from Pin1 and 7 can be used to trig transistor, MOSFET or as an input to microcontroller.
Here in the circuit diagram 9V battery is used, You may use DC power supply with help of transformer. Click on image to zoom.
3. Resources:
Rectifier Circuit if you want you use transformer instead of battery.
Download Data Sheet of LM358 here.
Buy This Kit from Robo India Store
If you have any query please write us at support@roboindia.com
Thanks and Regards
Content Development Team
Robo India
http://roboindia.com