All amplifiers some sort of power amplfiers

Discussion in 'General Electronics Chat' started by gusmas, Sep 3, 2009.

  1. gusmas

    Thread Starter Active Member

    Sep 27, 2008
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    Guys is every amplifier some sort of power amplifier. and if not where can i see examples of none power amplifiers.
    thx
     
  2. bertus

    Administrator

    Apr 5, 2008
    15,645
    2,344
    Hello,

    NO.

    There are a lot of different types of amplifiers.
    There are also LNA (low noise amplifiers) used in the RF techniques.
    There are pre-amplifiers, used for amplying teh signal of a microphone or MD element.

    Here is a link to a page of the EDUCYPEDIA on amplifiers:
    http://www.educypedia.be/electronics/amplifiers.htm

    There are also operational amplifiers (OPAMPS):
    http://www.educypedia.be/electronics/analogopamp.htm

    And there are instrumentation amplifiers:
    http://www.educypedia.be/electronics/Instrumentation.htm

    Greetings,
    Bertus
     
    Last edited: Sep 3, 2009
  3. gusmas

    Thread Starter Active Member

    Sep 27, 2008
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    I cnt undrstand , because a ampilifier either amplifies the input current or input voltage, and the formule for power is P=V * I. I thnk i have the concept wrong?
     
  4. Wendy

    Moderator

    Mar 24, 2008
    20,765
    2,535
    You're right, but different components act differently at different power levels. A circuit that has 1KW in and 500KW out is a lot different than one that takes 50µv in and ouput 500mv.
     
  5. bertus

    Administrator

    Apr 5, 2008
    15,645
    2,344
    Hello,

    Ok, when you look at the difference between in and out you are right.
    But they speak of poweramplifiers when they can deliver a lot of power.
    A normal opamp is often called a low power amplifier.
    An amplifier that can drive for instance a speaker or motor, we can all them power amplifiers.
    It is how you look at the concept.

    Greetings,
    Bertus
     
  6. GetDeviceInfo

    Senior Member

    Jun 7, 2009
    1,571
    230
    you could say that every amplifier is some sort of power amplifier. A typical application does indeed increase the signal strength, hence the 'power' of the signal.

    However, the circuit surrounding an amplifier may not be designed to strengthen, but rather modify the signal. Active filters are but one example. In these cases, the integration of the package is it's advantage, as opposed to it's 'amplifying' properties.
     
  7. mik3

    Senior Member

    Feb 4, 2008
    4,846
    63
    Every amplifier amplifiers power. People gave names to some specific kinds of amplifiers because some amplify voltage in a greater degree than current and vice versa.
     
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