Audio power amplifiers, Single stage transistor amplifier & Multistage amplifier

Audio power amplifiers Power amplifiers handles large signals (not very large). Size of power transistor is large, to dissipate heat. Tuned amplifier is used in RF application. Class A power amplifier uses one transistor, this transistor never turn off which is its main disadvantage. Driver stage commonly uses class A. Class A amplifier is most …

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Bipolar junction Transistor – BJT

Emitter is moderate size and heavily doped. Collector is large in size and moderately doped. Base is thin and lightly doped. When collector supply is 5V then collector cut off voltage is 5V. Zero signal condition is when transistor see dc load. Cut-off region – both junctions are reverse biased, Saturation region – both junctions …

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Semiconductor diode, Break down diode and Tunnel diode

Semiconductor diode Ideal diode conduct current in only one direction. Forward resistance of ideal diode is zero. Reverse bias resistance value is infinity. Barrier potential is generated by diffusion of electrons. PN diode can be made by alloying technique, diffusion technique, vapour deposition technique (epitaxial growth), rate growth technique Thickness of depletion region is 1 …

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Cycloconverter and inverter

Cycloconvertor Cycloconvertor converts AC signal of a particular frequency to another AC signal with different frequency, without using an intermediate DC stage. It is also called single stage frequency converter. it is classified into two. Step up cycloconverter – output frequency is greater than input frequency Step down cycloconverter – output frequency is lesser than …

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Battery, Dual converter and Phase controlled rectifier

Sulphation in a lead acid battery occurs due to incomplete charging. Capacity of a cell is measured in ampere hour. Lead acid battery is used in electric power station. Nickel cadmium battery is used in aeroplanes. Common impurity in battery electrolyte is iron. The indication of the state of charge of a battery is best …

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