Introduction
The circuit works in the basic concept of Transistors.Low-frequency audio signals came from Audible devices. This signal is too low to hear with a Speaker.Here one transistor is used so it means it can only give the mono output. If you need Sterio output then you have to use 2 IRFZ44N N-Channel MOSFETS.
Suppose we are talking about the left signal. The left signal has 2 wires one is a Left Signal Wire and another is GND. The GND wire is the same for both the Left and Right channels. But the channel wire is different for different channels.
The signal wire goes into the Transistor’s Gate Pin. Now the Transistor Switches On and off for the consequent frequencies. For this, the Transistor’s Drain and Source voltage differ.
For this, the small signals will be amplified. And the bandwidth will also be high. Now We can hear the loud sound from the speaker.
Circuit Diagram
Notes:
This is a simple Circuit. So there are some disadvantages to the circuit. That’s why this circuit is not for practical application purposes. There is no noise cancellation in the circuit. So, you will find extra humming noise in the amplifier.This amplifier can give you a hearable sound but not too much loud sound.This is a Mono amplifier. You can make it Stereo by just using the same other circuit.There is too much loss in the circuit. This is not power efficient. So nowadays Home theaters and other Music Systems use the Class D amplifier. The Class D amplifier has an efficiency of 80 to 90%. The Basic and popular class D amplifier is PAM8403. It can drive 2, 5W Speakers with ease. It can give a maximum of 10W outputs. And the main thing is that the board doesn’t need high voltages. It can run with 3v to 5V Power. It is great for portable Bluetooth Speaker Systems. But all in all, it is a great circuit for a hobbyist. They can practice the circuits for fun.