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Electronic Circuits

COMMON EMITTER CIRCUITS

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Electronic Circuits

AMPLIFIERS CAN BE CLASSIFIED AS EITHER:

VOLTAGE AMPS

POWER AMPS

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Electronic Circuits

Voltage amplifiers are used to increase the level of an input signal.

The amp may accept an input voltage of a few millivolts p-p and amplify the voltage to several volts p-p, then apply that voltage to another circuit or device.

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Electronic Circuits

Power amps are used to increase the power level of an input signal.

The power amp delivers a lot of power to a load by accepting a relatively low input current and producing a high output current.

A low resistance load is necessary to develop a high output current.

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Electronic Circuits

When using transistors as the principle controlling element in an amp circuit, three circuit configurations are possible.

When using transistors as the principle controlling element in an amp circuit, three circuit configurations are possible.

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Electronic Circuits

There are three common amplifier circuit configurations that were addressed in semi-conductors.

WHAT ARE THE 3 TRANSISTOR CIRCUITS?

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Electronic Circuits

THE THREE AMPLIFIER CIRCUIT CONFIGURATIONS ARE:

1) COMMON-EMITTER

2) COMMON-BASE

3) COMMON-COLLECTOR

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Electronic Circuits

The three circuit configurations are formed by using the emitter, base or collector lead as the common lead.

THE COMMON LEAD IS CONNECTED TO CIRCUIT COMMON OR GROUND.

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Electronic Circuits

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Electronic Circuits

THE COMMON EMITTER CIRCUIT IS THE MOST COMMONLY USE CIRCUIT

CONFIGURATION.

This configuration is often used to increase the level of an input voltage.

The voltage gain is expressed as a ratio:

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Electronic Circuits

Both voltage and power amps can also be classified by frequency:

DC AMPLIFIER - 10HZ OR LESSAUDIO AMPVIDEO AMPRF AMPIF AMP - INTERMEDIATE FREQUENCY

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Electronic Circuits

In some cases, one amplifier stage must be joined or coupled with another amplifier circuit to provide a higher overall gain.

When we connect multiple amplifier circuits together we refer to it as amplifier coupling.

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Electronic Circuits

THEY ARE FOUR BASIC COUPLING METHODS USED:

1. RC COUPLING- RESISTANCE CAPACITANCE.

2. IMPEDANCE COUPLING- USES AN INDUCTOR.

3. DIRECT COUPLING.4. TRANSFORMER COUPLING.

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Electronic Circuits

RC COUPLED AMPLIFIERS

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Electronic Circuits

IMPEDANCE COUPLED AMPLIFIER

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Electronic Circuits

DIRECT COUPLE AMPLIFIER

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Electronic Circuits

TRANSFORMER COUPLED AMPLIFIER