Guys is every amplifier some sort of power amplifier. and if not where can i see examples of none power amplifiers.
thx

 

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

 

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?

 

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.

 

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

 

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.

 

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.