Class B Push Pull Amplifier - Solid-state Devices and Analog Circuits Day 7, Part 2

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Class B push-pull amplifiers are more efficient than Class A amplifiers.

[aladin]

Absolutely simple way to explain the functioning of electronic ccts. This gentleman has a knack for explaining electronics very well and he is very knowledgeable.

[jnc]

Thank u very much sir... This is very helpful video... Keep up the good job and godbless.😊

[Kartoffelsuppe_m_Wursteinlage]

I plan to build a 1959 DDR retro radio using transformers and germanium transistors and the old schematic.
I really like this old technology of drive two transistors through two transformers.
Sounds strange, but it's just a learning project. ;)
BTW: Great content, thank you very much Professor!! By far the better way to learn electronics is to first get a general understanding of what actually happens and then practice the math. I really missed this approach during my time as a student. In the lecture my prof couldn't say what the essence of a Fourier transformation is. ;)

[ItsMe-ydms]

Lots of electronics books lay out circuit diagrams but don't really explain what each individual component does. Here this is detailed where the purpose of each component is thoroughly explained. Super helpful.

[g-kats]

13:00 - Should not a right end of a capacitor be connected between diodes? In your scheme its connected below both diodes. Let's say positive signal comes in. Current won't flow up - bottom diode blocks it. It also won't open PNP transistor. it can only go down trough resistor to -10v and this does nothing useful. After plugging these diodes you should show how current flows from input and which way to output. Marking voltages is not enough to me to not have doubts. Maybe your sheme is correct, but then I do not understand what happens at PNP base node. How input signal voltage influence potential at that node?

[uni-byte]

Yes Bob, but if the diodes are not properly matched to the BE junctions of the transistors and have the same thermal characteristics you risk thermal runaway. However, you can use the same spec transistors as the diodes. That way you can get sufficiently close matching easily and without the effort of selecting the right diodes.

[grzesiekx]

this is very intetresting! Finally something not too easy for my projects :) I am using those kinds of amplifier (I have circutis from books etc.) but it is always better to have more understanding how they exactly work so I can design them better :) I have built recently my AM radio for 225 kHz from scratch and need to improve my amplifier to have better sound quality.

[BoxingDayAC]

I'm genuinely impressed you show a Class B with diodes for biasing. Extremely common internet mistake is saying biasing is the difference between B and AB.

[manaoharsam]

You did a fantastic job in explaining.

[charlesschneiter]

That's one neat trick with this two diodes!
Thanks for this video!

[baffel]

Thanks! Great explaining video, even for a slow learning hobby beginner.
I have been struggling with npn pnp and the basics a long time to get it in my head.

[RobbyMatthias]

I have seen this in a lab-book!They used a pair of (2N3904, 2N3906) transistors', and two (1N914) diodes'. I hope you will cover the subject of speaker 'impedance-matching' to this amp in the future!Thanks' for a great video/class!

[ecananth]

hi sir, you are a great teacher for me. I always refer your videos for understanding circuits .can Make video on all (a, b, c and ab) class amplifiers and network theorems pls pls pls😅.

[grzesiekx]

7:39 one question, of there are no resistors, only transformers I am always worried about too much current going into the base of those transistors. How is that possible that they are not overloaded with current. I mean I understand how transformers work but still there is quite a lot of current going int othe base right?

[d]

1:05 Class A: Why does half current during silence translate to 100 W? Isn't half current the same as one-quarter the rated power?

[jesterraj]

HI can you do one on bias transistors in and out put power amp stage?

[johng.]

Would it be possible to explain other classes of amplifiers like C, D, and E class amplifiers?

[jshellenberger]

Bluetooth wireless headphones piezoelectric on a charger with 5V C port, down from 24V. USB charging on 60hertz. #POW

[johng.]

I was watching a video about vacuum tube amplifiers and the person covered class B amplifiers.

He showed a graph of voltage vs. current and how class B amplifiers operate starting from the cut off region:


So looking at the voltage vs. current graph class B amplifiers operate partially in the non linear region meaning they introduce distortion beyond just the cross over distortion.

So, wouldn't something similar occur with transistor based class B amplifiers?

[omiza]

Those 2 diodes are really confusing me my brain goes overheat