Introduction

Amplifiers are circuits that increase the input power of a system at the output. Therefore, the audio amplifier enhances the audio amplitude of the input signal. Also, the gain of this audio amplifier circuit gives you an idea of how well the output is amplified. How to make an audio amplifier with a 2SC5200 transistor? We will see this in the following tutorial.

Designers divide amplifiers into preamplifiers and power amps. Power amplifiers are further divided into many other types. Or you could say that an amplifier device typically has two stages, a preamplifier that only amplifies the voltage gain and not the current gain, and a power amplifier that causes power modification of the audio signal. And, this article is about audio power amplifiers.

What is Transistor?

Transistors are divided into two categories: bipolar transistors (Bipolar Junction Transistor-BJT, divided into NPN type,

PNP type), unipolar transistor (Field Effect Transistor, Field Effect Transistor-FET). Among them, the field effect tube is also divided into

JFET and MOSFET are junction tubes and metal oxide tubes, which are divided into N-channel and P-channel. Follower

In terms of numbers, transistors can be drawn into 8 types, 2 types of bipolar type, and 6 types of unipolar type, as shown in the figure above.

The so-called bipolar transistor refers to the inside of this transistor, which has both electron movement to form current and hole movement

A current is formed, one is more, called many sons, one is less, called few sons, the direction of movement of the two is opposite, and they fly to two different

"poles". In the so-called unipolar transistor, only holes or only electrons move to form a current, and only many electrons exist.

Fly to a single "pole".

Transistors can form common emitter (source) level, common base (gate) pole, common collector (drain) pole amplifier circuits, and

Various types of multi-stage amplifier circuits.

Students who have studied transistor amplifier circuits will more or less feel the complexity of transistors and their amplifier circuits. from static

Starting from the operating point of the state to the micro-variant equivalent circuit, and then to the gain calculation, input resistance, output resistance calculation, and frequency characteristics

It is not easy to complete an amplifier circuit that meets the requirements of various indicators. Although this magnified

The devices used in the circuit are very cheap, and the number of resistors and capacitors is not very large, but complex calculations limit this kind of amplification circuit

promotion.

Required Hardware

circuit diagram

In this audio amplifier with a 2SC5200 transistor, when you supply 12V to the circuit and provide input audio, capacitor C1 blocks the DC component of the base of the transistor. A potentiometer controls the input voltage. Now, an AC signal is generated at the base of the transistor and acts as a control signal. The collector of the transistor drives the speaker. So the speakers produce amplified audio.

Applications

l Hi-Fi equipment

l toys

l audio instruments

l public addressing systems