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CareerEd LibreTexts

1: Amplifiers and Active Devices

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  • [ "article:topic-guide", "authorname:tkuphaldt", "license:gnu" ]

    • 1.1: From Electric to Electronic
      This third volume of the book series Lessons In Electric Circuits makes a departure from the former two in that the transition between electric circuits and electronic circuits is formally crossed. Electric circuits are connections of conductive wires and other devices whereby the uniform flow of electrons occurs. Electronic circuits add a new dimension to electric circuits in that some means of control is exerted over the flow of electrons by another electrical signal, either a voltage or a cur
    • 1.2: Active Versus Passive Devices
    • 1.3: Amplifiers
      The practical benefit of active devices is their amplifying ability. Whether the device in question be voltage-controlled or current-controlled, the amount of power required of the controlling signal is typically far less than the amount of power available in the controlled current. In other words, an active device doesn’t just allow electricity to control electricity; it allows a small amount of electricity to control a large amount of electricity.
    • 1.4: Amplifier Gain
    • 1.5: Decibels
    • 1.6: Absolute dB scales
      It is also possible to use the decibel as a unit of absolute power, in addition to using it as an expression of power gain or loss. A common example of this is the use of decibels as a measurement of sound pressure intensity. In cases like these, the measurement is made in reference to some standardized power level defined as 0 dB. For measurements of sound pressure, 0 dB is loosely defined as the lower threshold of human hearing, objectively quantified as 1 picowatt of sound power per square me
    • 1.7: Attenuators