Introduction: OPAMP(741 Types) AND 555 TESTER
OPAMPS and 555 timers are one of the widely used electronic ICs that we use regularly, So we need to make sure that whether ICs are working correctly or is faulty. Thus we need to make a tester that will help us to test whether those ICs are working properly. If tester does not give desired output, then the IC can be faulty and needs to be replaced. Therefore a tester should be made and must be handy and portable.
Here we considered only the 741 OPAMP IC types and equivalent. And the standard 555 timer IC. Both should be in DIP(Dual Inline Package) package as the tester is made for DIP packages only. So let us proceed.
Step 1: Gathering Components
1. 8 pin IC tester ZIF (zero insertion force) socket, DIP
2. 3 LEDs
3. 1 meg, 3 220ohm, 1 100ohm, 2 100khom, 1 1k resistor
4. 1 10uf, 1 1uf, 1 47uf polar electrolytic capacitor, voltage rating 16v
5. veroboard and soldering kits
6. 555 and 741 (or equivalent) for testing
7. Breadboard for testing
8. 9v or 12v battery
Step 2: Making the Circuit
Now gather all components and test on breadboard. Test both circuits. If LEDs blink then IC is okay. If LED does not blink ( permanently on or off), then IC is malfunctioning and faulty. For 741 there are 2 LED that will blink alternatively and for 555 there is a single LED that will blink. I've already tested on breadboard before . So I directly soldered them on a piece of veroboard/ perfboard/zeroboard.
The 741 section is an astable multivibrator that will blink 2 LEDs at output.
The 555 is also set as an astable multivibrator that will blink a single LED at output.
Detailed calculation, circuit is provided in the Pics attached here.
Circuits can be easily run using a 9V battery or a 12V battery.
Principle of working of astable multivibrator can be easily found on google.
Step 3: Finally...
After soldering the circuit will look like this. And the video link:
shown will give the proof that the ICs we have taken are okay. If LEDs blink then IC is okay. If LED does not blink ( permanently on or off), then IC is malfunctioning and faulty. For 741 there are 2 LED that will blink alternatively and for 55 there is a single LED that will blink. The lower half is for the 741 and the upper half is for 555. Alternatively, the 2 LED section is for 741 and single LED section is for 555. It is also clear from your circuit diagram. So test all your 555 and 741 types. Happy circuit journey.
Note- 741 types and equivalent- TL071, NE5534, OP07, CA3140, MCP601, etc.