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What is a passive amplifier?

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hazemafify

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What does Passive Amplifier mean ?
 

kevpat

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Re: Passive Amplifier

Well there is no such thing as a passive amplifier (as far as I am aware) as you need a power source to amplify. However I think you may be thinking about Passive pre-amps in audio applications. These are actually passive volume control circuits that take the place of traditional pre-amp circuits mainly because the signal output of cd's etc don't need an additional pre-amp stage so a passive volume control reduces cost and can improve sound quality (though this depends on how well you design the circuit).
 

hazemafify

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Re: Passive Amplifier

kevpat said:
Well there is no such thing as a passive amplifier (as far as I am aware) as you need a power source to amplify. However I think you may be thinking about Passive pre-amps in audio applications. These are actually passive volume control circuits that take the place of traditional pre-amp circuits mainly because the signal output of cd's etc don't need an additional pre-amp stage so a passive volume control reduces cost and can improve sound quality (though this depends on how well you design the circuit).
Can you discuss more about what is called Passive pre-amps?and what the most common circuit if it ?.

Thanx in advance.
 

noam_tz

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Re: Passive Amplifier

I know 3 examples of "passive" amplification:

1) mechanical amplifier

Interesting implementation:
http://www.dself.dsl.pipex.com/MUSEUM/COMMS/mechamp/mechamp.htm

2) Acoustic amplifier - like a horn (Pressure amplification versus velosity reduction and vise versa)

3) Passive voltage amplifier - like a transformer, resonance circuit and so on

Of cource you won't get something for free... passive amplifying the voltage would attenuate the current...
 

hazemafify

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Passive Amplifier

My question is what is the meaning of passive op-amps? is the meaning of passive is no capacitances or inductances ? and what about meaning of second order passive amplifier?.
Thanx
 

Borber

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Re: Passive Amplifier

Passive pre-amp can be audio pre-amp consisting of connectors, switch and potentiometer. Audio power amplifier with enough gain (giving max power at nominal audio level) does not need any amplification in pre-amp, only attenuation (potentiometer).
Passive op-amp is nonsense.
 

hazemafify

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Re: Passive Amplifier

Borber said:
Passive pre-amp can be audio pre-amp consisting of connectors, switch and potentiometer. Audio power amplifier with enough gain (giving max power at nominal audio level) does not need any amplification in pre-amp, only attenuation (potentiometer).
Passive op-amp is nonsense.
What is the pre-amp?, and what is the meaning of this "Passive op-amp is nonsense"?.
Thanx
 

IanP

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Re: Passive Amplifier

Are you sure you aren't after PASSIVE FILTER, which can be of the 1-st, 2-nd, 3-rd (and so on) order ???
"PASSIVE AMPLIFIER" sounds weird ..

Regards,
IanP
 

Borber

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Re: Passive Amplifier

In electronics a term passive amplifier simply does not exist. Amplification must be made of active elements like transistors or operational amplifiers (op-amps) and no passive element can do amplification of electrical signal except transformer. But this was said in previous posts.
Passive op-amp (operational amplifier) does not exists. It's an active semiconductor device.
Tell us what you want to do with this passive amplifier. What should be it's main function?
 

Borber

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Re: Passive Amplifier

Yes transformer does not amplify power but can "amplify" voltage.
 

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