How to test Opamp 741?

Sameer Shetty's picture


Joined: Sep 03, 2018

Replies: 2
How to test Opamp 741?
September 3, 2018 - 3:34pm

Hello guys, i am making a wireless switch circuit using LM741 Opamp IC following the below circuit diagram. But the circuit is not working, Is there any mistake in the circuit ? I double checked the connections but didn't find any false connections, so I think op-amp IC is faulty. So is there is any way to test opamp whether it is working properly or not?

Thank you....


Abhishek's picture


Joined: May 19, 2015

Replies: 403
Circuit diagram looks fine, I
September 4, 2018 - 1:13pm

Circuit diagram looks fine, I hope you have connected Pin 7 and 4 to the power and ground respectively.

Other than that if you want to test the op-amp IC, then you just need few resistors and diode. Below is the circuit to test the Op-amp IC

opamp tester circuit diagram

If LED blinks means that op-amp is fine and if LED will remain on or off means that op-amp is faulty.

Instead of making this tester circuit try with another Op-amp, and if you dont have 741 then, try with some other op-amp IC. Looking at your circuit I think any op-amp IC should work, just check the pin configurations. 

Aswinth Raj's picture


Joined: Aug 16, 2016

Replies: 878
Test you Op-Amp in voltage follower mode
September 5, 2018 - 5:22pm


The best and quick way to check if you Op-Amp is working in good condition is by testing it as voltage follower.

You can find complete discussion here:


Sameer Shetty's picture


Joined: Sep 03, 2018

Replies: 2
Op-amp tested good, battery problem
September 7, 2018 - 11:19am

Thanks guys, I tested my Op-amp and found that it is working properly. So I again checked my circuit and found that the culprit was my 9V battery.

When measured at no load the battery has a potential of 7.2V but when connected to load it drops to 3.7V which is not enough for the circuit to work. I replaced the battery with a fresh 9V one  and the circuit is not working fine.

Thanks again