Linked Questions
19 questions linked to/from Transfer function of a LM380 power amp
6
votes
3
answers
6k
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Why do Class AB amplifiers use a pair of diodes instead of a resistor?
I understand that in a Class AB amplifier, a pair of diodes are placed between the bases of the two transistors to slightly forward bias both bases.
Why are diodes typically used to provide the ...
- 141
6
votes
3
answers
3k
views
Cascading common emitter and common collector
I am trying to design an amplifier for a 1 W 8 ohm speaker for educational purposes. The idea is to start from a common emitter amplifier to amplify voltage and then add a common collector (emitter ...
- 297
5
votes
2
answers
2k
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Is there a difference between specialized audio amplifier and general op-amp silicon?
I've been doing some research into creating a DIY audio amplifier from line-level inputs to speaker level power. I found a guide centered around the LM386 Low Voltage Audio Power Amplifier on YouTube ...
- 177
9
votes
3
answers
2k
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How to properly use an op-amp?
ever since posting here I never been so lost of using op-amps before, hearing new things that I have never heard before (Vom, Vcm etc). I always thought OP AMPS is just plug it in and it will work ...
- 1,421
1
vote
3
answers
2k
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BJT 2 stage Amp. Output problem
So I built the following circuit to amplify the output from my microphone. I am testing it using a 1KHz sinewave of 10mV peak value. The Mic is biased using a 10k resistor. The signal is input into a ...
- 600
2
votes
1
answer
2k
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BJT Differential amplifier design and issues with gain and DC operating point
I am working my way through the Art of Electronics and I have today studied the differential amplifier. I aam having issues with Exercise 2.18: Design a differential amplifier to run from ±5V supply ...
- 63
1
vote
1
answer
623
views
Common emitter bjt amp Q point with and without current mirror
What is the real benefit of voltage divider CE BJT amplifier schematic like that? If I use different BJT's in real life with various betta I'll give different voltage drops XMM1. Different betta of ...
- 385
0
votes
3
answers
1k
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Protection diodes in an audio amplifier
How do the diodes protect the input of amplifier from excess voltage in the circuit below?
- 5
1
vote
2
answers
673
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Cant understand an ab amplifier diagram
I been trying to figure out this diagram, and Can't understand what happens from the beginning of the input , how the voltage changes in a way that "shuts off" one transistor. Also cant understand the ...
- 111
0
votes
3
answers
1k
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Effect of the Load on a Class AB Amplifier
I am getting into the world of analog electronics, although it is much more challenging it is much more interesting. Im dabbling into audio and would like to build an op-amp amplifier followed with a ...
- 47
1
vote
3
answers
1k
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How does the LM386 work?
I am not an electrical engineer, but I am curious enough and my mind tells me to make a radio circuit.
Now I am into it, so to make one, I need some components, but before that so that I can be a ...
- 189
1
vote
3
answers
694
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What is making this LM386 circuit so distorted?
I found this circuit on a YouTube video and tried copying it down into a circuit for testing, but the audio that comes out of it is really low quality and distorted. I don't expect sterling quality ...
3
votes
1
answer
661
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How is the quiescent current and emmiter resistor determined on the driver and pre-drivers of a class-AB audio amplifier output stage
I am reading online about discrete audio amplifiers. I have learned about the input differential pair, the voltage amplifier stage, and now I'm learning about the output stage. I have learned that you ...
- 33
1
vote
1
answer
328
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I can't figure out what this circuit does
I'm an electrical engineering student.
The picture below shows a circuit that I found in some old notes but I cannot figure it out.
I have been at it for the last 2 days but to no avail.
Some things ...
- 59
0
votes
2
answers
466
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How to find collector resistor value in bjt differential amplifier
What value R2 may have in that schema? Anyway it will be loaded by pn-junction of Q5 and will have fixed voltage drop near 0.65V.
What value R2 must have if the current source is used instead R1? The ...
- 385
-1
votes
2
answers
172
views
transistor amplifier
My teacher asked me to design an amplifier circuit using BJT transistors with following properties: (Is=10fA , beta=100, Vce sat =0.2)
I can use as many transistors as i want but i try to minimize the ...
0
votes
1
answer
235
views
BJT differential pair on breadboard enters saturation
I've built the following circuit on a breadboard (for the purpose of experimentation) and measured the voltages:
IN+ and IN- ...
- 1
1
vote
1
answer
87
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Searching for known subcircuits
I want to solve this exercise in the figure below.The question is "Recognise as many known Sub-circuits as you can in LM386 circuit".I tried it and found only that the transistor down and in the left ...
- 394
0
votes
1
answer
156
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How to identify the transistors that are active loads
I have found this exercise online, I'm currently learning about current mirrors and I don't really get this concept of a transistor acting as a load. Can someone explain? Which transistor is an active ...
- 107