If you have designed projects, there's a good chance that due to some unknown reasons, you don’t get the desired output. At times, this happens due to poor wiring or soldering gaps, but these can be easily identified and fixed. However, when it comes to an IC, it becomes very difficult to test the working of an integrated circuit. This project by lonesoulsurfer demonstrates the way of checking commonly used ICs like the LM358, LM386 and LM741 with his custom PCB.
As we all know, any operational amplifier IC has an inverting and non-inverting input, and this tester circuit uses the voltage comparator that is already present inside this IC. When there is a 50% duty cycle the output is always a square wave that results in flashing of the LED. Using this concept, this project works in a way that any IC tested on this PCB with a blinking LED is perfectly fine. If the LED stays on or off that means the project is not operational because of the faulty IC.
One of the interesting facts of this PCB is that lonesoulsurfer has provided several ways to power the tester, with one using a 9V battery. The PCB doesn’t only test three op amps but is also capable of evaluating vactrols and optocouplers.
The low-cost IC tester is available on Instructables — along with the schematic and files — for you to recreate or modify to suit your needs.