Amplifier = straight wire + gain
http://www.diyvideo.com/forums/attachment.php?postid=294591
Amplifiers usually split their gain into two areas: voltage and current.
In the above diagram the transfomer provides the voltage gain, the transistors the current gain. It runs in class A.
http://www.diyvideo.com/forums/attachment.php?postid=294591
Amplifiers usually split their gain into two areas: voltage and current.
In the above diagram the transfomer provides the voltage gain, the transistors the current gain. It runs in class A.
oxford advanced learner's dictionary says this:
amplifier: a device for amplifying sth, esp sounds or radio signals.
amplify: 1 to increase sth in strength or intensity, esp sound; 2 to add details to a story
Lets hope the big chip manufacturers & others overlook the second meaning of 'amplify'.
amplifier: a device for amplifying sth, esp sounds or radio signals.
amplify: 1 to increase sth in strength or intensity, esp sound; 2 to add details to a story
Lets hope the big chip manufacturers & others overlook the second meaning of 'amplify'.
djk said:In the above diagram the transfomer provides the voltage gain, the transistors the current gain. It runs in class A.
I prefer the 2nd kind: transistors for voltage gain and transformers for current gain.
Matjans,
you obviously have a different version of the Oxford dictionary,
although the differences are not big. In my version amplifier is
defined as I stated above, while the applicable one of the
definitions for "amplify" is "increase the strength of (voltage,
current etc.)"
It seems my version (3rd edition, 1985 revision) takes a more
strict and technical view, while your version is more in line
with general language usage.
Anyway, I suppose we are mostly interested in the technical
definition of the term here, not what a dictionary says. My
previous post was partially meant as a joke, since I wasn't
sure if the original question was seriously meant, and if
it was, it might easily lead to an endless philosophical discussion.
All,
I don't expect people to come to an agreement on this term.
For instance, does an amplifier have to amplify at all, or can
we also consider degenerate cases which actually has a gain
less than 1 for both current and voltage?
We certainly do not require a gain >1 for both current and
voltage, since otherwise neither a follower nor a CB stage could
be considered to amplify.
you obviously have a different version of the Oxford dictionary,
although the differences are not big. In my version amplifier is
defined as I stated above, while the applicable one of the
definitions for "amplify" is "increase the strength of (voltage,
current etc.)"
It seems my version (3rd edition, 1985 revision) takes a more
strict and technical view, while your version is more in line
with general language usage.
Anyway, I suppose we are mostly interested in the technical
definition of the term here, not what a dictionary says. My
previous post was partially meant as a joke, since I wasn't
sure if the original question was seriously meant, and if
it was, it might easily lead to an endless philosophical discussion.
All,
I don't expect people to come to an agreement on this term.
For instance, does an amplifier have to amplify at all, or can
we also consider degenerate cases which actually has a gain
less than 1 for both current and voltage?
We certainly do not require a gain >1 for both current and
voltage, since otherwise neither a follower nor a CB stage could
be considered to amplify.
osey said:I think people are missing the point here, that amplifiers do not have to be restricted to descriptions of current and voltage?
Think of an amplifier as just a ssystem block with constant gain, with an input, and an output. Thats all there is really.
Quite right, it is a system block, not necessarily an electric one.
However, that makes it even harder to define what is and what
isn't an amplifier. Is it required to be linear even in the ideal
case for instance? Mathematically it is a function from one or
several variables to one or several variables with certain
characteristics, but which ones? I suppose systems theory
has some general definition of the concept though.
We are getting more and more into the philosophical discussion
I anticipated, so the question is, what was the purpose and
ramifications of the original question?
osey said:I think people are missing the point here, that amplifiers do not have to be restricted to descriptions of current and voltage?
Think of an amplifier as just a ssystem block with constant gain, with an input, and an output. Thats all there is really.
I have worked with hydraulic pressure amplifiers in the Air Force. Presumably there exist also pneumatic pressure amplifiers, commonly known as "compressors"??
BTW, The second definition given above (to add detail to a story) seems to gain more and more priority in audio advertisement.
Jan Didden
Re: What is an Amplifier..??
On the other hand, a regulated power supply is essentially
an amplifier where the input signal happens to be constant,
the voltage reference, so this definitions tends towards
being circular.
I don't agree that a compressor is an amplifier, unless its
output pressure/flow is controlled by some input signal.
Hm, maybe it is after all, if considering it as a pneumatic
version of a power supply?
The wrench, yes, is it an amplifier, or is it rather some kind
of converter? I think it is analogous to a transformer, so
I would say it is rather a converter (scaling up one thing
and scaling down another by the same factor).
LesW said:A device or contrivance for modulating a power supply..??
On the other hand, a regulated power supply is essentially
an amplifier where the input signal happens to be constant,
the voltage reference, so this definitions tends towards
being circular.
I don't agree that a compressor is an amplifier, unless its
output pressure/flow is controlled by some input signal.
Hm, maybe it is after all, if considering it as a pneumatic
version of a power supply?
The wrench, yes, is it an amplifier, or is it rather some kind
of converter? I think it is analogous to a transformer, so
I would say it is rather a converter (scaling up one thing
and scaling down another by the same factor).
A simple wrench could be seen as a torque amplifier. The longer the wrench, the higher the torque "gain".
I am afraid that this wouldn't count. IMO an amplifier is a device that must have larger output power than is used to drive (i.e. not to supply) it.
Regards
Charles
phase_accurate said:
I am afraid that this wouldn't count. IMO an amplifier is a device that must have larger output power than is used to drive (i.e. not to supply) it.
Agree. A wrench is a torque transformer, not amplifier.
Peter
Not that I consider the US patent office an authority on
terminology, but here is their definition of amplifiers in
the case anyone is interested and has the patience to read it.
http://www.uspto.gov/go/taf/def/330.htm
terminology, but here is their definition of amplifiers in
the case anyone is interested and has the patience to read it.
http://www.uspto.gov/go/taf/def/330.htm
phase_accurate said:
I am afraid that this wouldn't count. IMO an amplifier is a device that must have larger output power than is used to drive (i.e. not to supply) it.
Regards
Charles
wouldn't that depend on what you are amplifying? a wrench certainly amplifies the torque, and yours amplifies power (actually, it redistributes power on the load).
As Peter mentioned above the wrench is a transformer, i.e. a passive device.
An amplifier should be an active device that outputs more power (which it takes from some power source) than it is taking from its drive - (or control or whatever-you-call-it) input.
Regards
Charles
An amplifier should be an active device that outputs more power (which it takes from some power source) than it is taking from its drive - (or control or whatever-you-call-it) input.
Regards
Charles
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