How to Make a Simple Op-Amp Circuit

Imagine two whispers one with little louder.

Op-amp is smart listener.

It hears only the difference and ignores background noise.

It makes small difference bigger using voltage gain.

This Simple Op-Amp Circuit helps boost weak signals in electronics.

Circuit Working:

Parts List:

This circuit uses 3 transistors to make simple op-amp.

It work like class A, and AC amp gain to about 5000.

But we can use it like normal op-amp.

Output stays near half of power supply.

This happen because of voltage drop on 2 LEDs with input transistor and 1M resistor.

68k resistor and 4.7nF cap stop it from oscillate.

We can use this op-amp as filter or oscillator with 1k load.

It gives good square wave at 10kHz and drops 3dB at 50kHz.

How to Build:

How to Make a Simple Op-Amp Circuit need to follow the below mentioned steps for connections:

• Connect input to base of first BC547 with 33nF cap and 100k resistor.
• Connect emitter of this BC547 to point between 4.7k resistor and 2 LEDs in series.
• 4.7k resistor goes to positive and LEDs goes to negative.
• Connect base of BC557 to collector of BC547 using 68k resistor.
• Put 6.8k resistor between BC547 collector and positive.
• Connect emitter of BC557 to positive.
• Put 4.7nF cap from base of BC557 to ground.
• Connect collector of BC557 to base of second BC547 output.
• Connect emitter of this BC547 to ground.
• Connect its collector to positive with 1k resistor.
• Also connect this collector to output using 4.7uF capacitor.
• Connect 1M resistor from output BC547 collector to input BC547 base.

Note:

• We can change parts like resistors, capacitors to match our needs.
• Be careful when working with circuits.

Conclusion:

This How to Make a Simple Op-Amp Circuit is good for learning.

It shows how op-amps boost signals and controls voltage.

We can make filters, amplifiers and more.

Try different values to learn more and get better at electronics.

References:

Operational amplifier