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Electronic Circuits. COMMON EMITTER CIRCUITS. Electronic Circuits. AMPLIFIERS CAN BE CLASSIFIED AS EITHER: VOLTAGE AMPS POWER AMPS. Electronic Circuits. Voltage amplifiers are used to increase the level of an input signal.
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Electronic Circuits COMMON EMITTER CIRCUITS
Electronic Circuits • AMPLIFIERS CAN BE CLASSIFIED AS EITHER: VOLTAGE AMPS POWER AMPS
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.
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.
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.
Electronic Circuits • There are three common amplifier circuit configurations that were addressed in semi-conductors. WHAT ARE THE 3 TRANSISTOR CIRCUITS?
Electronic Circuits • THE THREE AMPLIFIER CIRCUIT CONFIGURATIONS ARE: 1) COMMON-EMITTER 2) COMMON-BASE 3) COMMON-COLLECTOR
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.
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:
Electronic Circuits • Both voltage and power amps can also be classified by frequency: DC AMPLIFIER - 10HZ OR LESS AUDIO AMP VIDEO AMP RF AMP IF AMP - INTERMEDIATE FREQUENCY
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.
Electronic Circuits • THEY ARE FOUR BASIC COUPLING METHODS USED: • RC COUPLING- RESISTANCE CAPACITANCE. • IMPEDANCE COUPLING- USES AN INDUCTOR. • DIRECT COUPLING. • TRANSFORMER COUPLING.