Introduction: Class AB AMPLIFIER

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Hey all!!

In this tutorial, i will try to explain how to make an amplifier circuit known as Class AB Amplifier.
There are a lot of amplifier circuits and have their circuit analysis methods as well. However, i will cover the only basic implementation of it with the two stages.

First stage consist of non-inverting amplifier circuit using Op-Amp. It is for the amplicitaion of small signal araound more than 20 times. However, we cannot drive any speaker with only non-inverting amplifier. In order to drive speaker, we have to build buffer circuit which provides sufficient current.
In the second stage, i have used Class AB Amplfiier.

There are varity of Class amplifiers such as Class A,B,AB,C,D,..... Each of them have different advantages and disadvantages. I have choosen the AB.

Here also i have video about this project. You can have a look at this video and see how it worked.
Note that : Video language is not in English , that is why i will try to explain important parts here as in English.

Step 1: Required Hardware

In order to be able to design such an amplifier circuit, i have used the following components.

x4 Power resistor (x2 330 ohms, x2 100k ohms)

x1 Resistor 1 k(not power resistor)

x1 50k or higher Pot ( recommended one is 50 or 10 k)

x1 TIP31 transistor

x1 TIP32 transistor

x1 AUX jack socket

x3 Terminals for connection to the PCB

x1 12v DC supply

x1 100uF Capacitor

x2 470uF Capacitor

Soldering will also be required after we have designed the board.

Step 2: Circuit Schematic and Working Principle

We can set up the circuit in simulation program. I have used Proteus.
Circuit consist of two stages. First one for the amplification of the Voltage(signal)
Second one for the amplification of the current.

Gain of the non-inverting amplifier is 1+ RF/R2 where RF and R2 shown in the Image.

In the second stage i have used Class AB with the resistor biased.

After that we can create a pcb circuit and save the gerber file in order to get fabrication.


After testing,simulating and drawing the pcb file, we can give an order. After that you get the gerber file you can upload it into PCBWAY and give an order.

Here my gerber file project link: Link Here

Step 4: Soldering the Components

After we get the PCBs, we can start soldering the related components on PCB and test it. Hint: one by one put the components on the pcb , flip it and solder it by one by .

Soldering part is shown in the video as well. You can just have a look at it.

Step 5: Subscribe My Channel If You Like

Hope it will be useful project in order to understand the principle behind the H-Bridge motor driver.

You can have a look at the video to see how this project works . If you like my project, you can have a look at others on my channel and you can support me . Don't worry about the language , mostly i prepare my codes with english explanation. If any question, you can either ask your questions from here or Youtube channel.

Do not hesitate for asking any question.

My Youtube Channel : YouTube Channel (ARDUINO HOCAM)

Please Let me know if you face any problem without any doubt!

Have fun!