Questions tagged [power-amplifier]
An electronic amplifier that amplifies a low-power signal in order to make it more suitable for an application that requires higher power (e.g. driving a speaker). Power amplifiers have special challenges compared to lower power amplifiers (e.g. a voltage amplifier, which amplifies a signal's voltage but does not provide much output current capability); such challenges include more board space, cooling components that are dissipating high power, etc.
319 questions
0 votes
3 answers
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Have I got this class B amplifier right?
I've got to do a class B amplifier, and my professor said to rely on this schematic from an old guidance book and I'm trying to replicate it. However, I can't really put my mind into it, especially ...
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3 votes
2 answers
308 views
Output impedance of an amplifier with complementary emitter follower output stage
Lately I've been reading Bob Cordell's "Designing Audio Power Amplifier" and while reading about the output stage (chapter 2.3 and 3.5) I got curious about the output impedance of ...
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-2 votes
1 answer
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SKY65900-11 Input level
I wanted to use SKY65900-11 2.4-2.5 GHz +28 dBm WLAN Power Amplifier, but when I checked its datasheet, it didn't mention the allowed input value. Has anyone worked with this IC?if YES. So how you ...
1 vote
3 answers
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Designing a class AB power amplifier using BJT
I want to design a power amplifier using BJT. My instructor has designed one for himself, but I have some issues in understanding that topic. The problem is to generate \$0.5W\$ across a speaker of ...
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1 vote
3 answers
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estimate hifi speaker cable diameter/cross section [duplicate]
I have the variables - speaker resistance 8 Ohms, amp power 70 Watts per channel @ 8 Ohms, plus speakers max 8 meters from the amp. Bit confused, but intrigued as to how to roughly calculate cable ...
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7 votes
5 answers
772 views
How do I diagnose the problems with this amplifier?
Roughly a year ago I foolishly decided to try to build this guitar amplifier from a site I found. Long story short, it doesn't work and I have a hard time understanding why. Circuit & test setup ...
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1 vote
2 answers
222 views
Designing a power amplifier using BJT
I have a question about designing a power amplifier, and I don't know how to match the different stages together! Question: Replace the first stage by folded-cascode and any current source by current ...
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2 votes
1 answer
126 views
Floating node in LTspice
I have a question about designing power amplifier. Question: Find the current of the current source I3. My solution: I supposed that the Vbe of Q1 is 0.6v and with Is=10^(-14) calculated the Ic1, ...
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1 vote
3 answers
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QSC Amp: How does the VAS op amp drive global output swing if its local output only moves ±1V?
Is the VAS op amp here really configured for a gain of 50? If that's correct, then why does it only output ~1V locally. And then how does ~1V end up becoming full swing on the speaker output? Any ...
0 votes
0 answers
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How can I convert S-parameters between series and parallel?
We evaluate RF amplifiers using actual equipment and a simulator (ADS). Since there are few types of inductance values for air-core coils that can be used in matching circuits over 100W, we make our ...
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0 votes
0 answers
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Simple and good RF power amplifier design needed (50MHz)
I am trying to design a good and simple RF power amplifier for a project of mine, but i am getting nowhere. I am quite new to RF electronics, therefore i would like to ask for some suggestions or ...
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2 votes
1 answer
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Grundig V2000 amplifier relay clicking – is T604 faulty or false DC detection?
I have an old Grunding V2000 audio amp. It has an output protection circuit that consists of an anti-pop circuit (delayed output relay turn on/instant turn off), and what I think is a DC detection ...
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3 answers
168 views
How to power a speaker?
I have created an analog synthesizer based on waveforms and signal concepts, but I only focused on the wave shape till now and not on the voltage levels. Now that I want to actually hear the output of ...
1 vote
2 answers
202 views
How to calculate power dissipation in Darlington transistors Class AB amplifier?
I’m designing a Class AB amplifier that needs to deliver up to 10 A RMS at frequencies as high as 100 kHz. The output stage uses Darlington transistors (TIP142 for NPN and TIP147 for PNP), powered ...
3 votes
1 answer
114 views
Would a thermistor cause noise in an RF power amplifier?
I'm currently working with an SOT-89 RF power amplifier that I am operating at ~400MHz. To measure the temperature, placed a large (1206) thermistor on top of thermal vias of the amplifier on the ...
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