From 1980 into 1983 I took an 8hr a day 5 days/wk Electronic course in a Vo-Tech school for my electronics degree. We went from basic theory all the way through Integrated circuits , micro chips and then on to a 30 yr career. Those were some of the most fun times in the begaining. I totally recomend these courses to anyone. The doors that were opened were wonderful.
Your voice is a signal from heavens for electronics enthusiasts like me ! You have a great sense of humour, explains well in depth and keeps us all in the mood !!
Am I missing something? In the A/B, D1 means there's no route for the signal to the NPN transistor, right? Only the PNP is going to amplify the what hits Vin.
what is the smallest ac signal these can multiply? what about tape head signals? well under 1mv. is it better to use an actual tape head preamp? ive seen op amps being used.
Great explanation of these different amplifiers. I used a constant current source top and bottom to get rid of the cross over distortion on a push-pull amplifier similar to the one you in another lesson. Thanks.
The B-E voltage requirement was because of the silicon material used in the transistor. I assume changing to germanium will lower it to 0.3 but that isn't really practical
Interesting how combining the two amplifiers makes for one better one. Checking out Device Plus and looks like some cool little projects there. Thanks!
caso craft Hi. Nah this isn’t an issue in a class A amp as the transistor is biased (you can tell by the fact that there’s a voltage divider with its output being the base). This means that the transistor is sitting in its active region (switched on, in laymen’s terms) at all times. The required 0.7V is always there because of the voltage divider. :)
It would have beneficial to everyone if you would have explained how the A/B amplifier removes distortion around zero cross. Was it because of the voltage divider/biasing resistors?
While I've been enjoying these videos, you don't really go into detail about what's going on in the AB. I don't think you even mentioned the inclusion of the diodes in the design. Regardless, I'll keep watching the videos :) Really trying my hardest to understand my new Op Amps class. It's fascinating.
BUT WHAT DO THE DIODES DO???? AGGGGHHHH IT'S DRIVING ME MAD! 🤪! I can't work it out. Each diode drops around 0.7v. why are facing the same direction? I just can't fathom what is going on. Other than that, great video 👍😁
I think what's happening here is that the diodes are blocking flow through them when the wave is high, leading to greater flow through the gate. This is most obvious with the NPN side, but the principle is the same on the PNP side, just flipped upside down. Now, you might wonder why the diode is pointing they way it is on PNP side, but that's because when Vin is in a trough, it's effectively going to have a kind of opposite effect on the PNP transistor and the diode on the negative side of Vin and Vout. What makes this confusing is mainly the nature of AC circuits if you're used to dealing with DC ones. That's at least my understanding, but it's something I think I'd need to verify in a simulator or in a board.
for the diagram with the class b amp, why do the transistors not turn each other on? (lol) npn turns on if current flows in, while pnp turns on when current flows out (or vice versa depending on physics or electronics), so why dont they turn each other on?
+fredlllll I think you're thinking in terms of DC current. Think in AC only one transistor is on per half cycle, the other half cycle it's reversed biased.
Ok, so website "Device Plus" appears to be a sort of techno-gizmo resource - but less of a "build X project" reference. That site links to ROHM via a single icon on the home page. Parts ROHM apparently manufactures are elaborated (with data sheets), and ultimately us DIY'ers are directed to distributors such as Mouser or Digi-key to buy. FWIW.
I was bamboozled by the Devices Plus site, thinking it had more "circuit content". The ROHM site appears substantially more useful to makers. Perhaps you will find some unusual devices made by them to evaluate and experiment with. They have speech synthesis and "energy harvesting" products, to name a few. For folk looking for parts, they may want to jump past Devices Plus, and head over to ROHM.
I just spent $50,000,000, and 17 cents'''' on a new scope when I could of got a paper one!!!! where did I put that god dam recite ???? hey,, I could make a scope out of it; ).. loved the video Paul was shouting "very quietly coz its 6:25 in the morning here" when you asked why it distorts.. but you couldn't here me; ) forward voltage drop. the voltage needed to turn on the transistor.. need to go to bed coz im not joking when I say I was getting frustrated that you didn't say yes your Keith.. just goes to show how much I was into the video!...! good night!!
Thanks for the overview. Isn't push-pull synonymous to class B/AB ? What would a non push-pull AB look like. I thought it meant that one transistor pushes voltage up and the other one pulls it down, kinda...
Class B is more efficient, class AB requires bias voltage on the bases of the transistors so the transistors are turned on for longer which gives less efficiency but reduces distortion. Also, class B is push-pull as well.
Sometimes I say transformer 2hen I mean transistor. It happens. If it bothers you I invite you to not watch any further videos on my channel. Videos are unscripted and I do say left when I mean up sometimes. But thanks for watchint.
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
Old is gold. I keep learning from 5 years ago material and its worthy
From 1980 into 1983 I took an 8hr a day 5 days/wk Electronic course in a Vo-Tech school for my electronics degree. We went from basic theory all the way through Integrated circuits , micro chips and then on to a 30 yr career. Those were some of the most fun times in the begaining. I totally recomend these courses to anyone. The doors that were opened were wonderful.
Your voice is a signal from heavens for electronics enthusiasts like me ! You have a great sense of humour, explains well in depth and keeps us all in the mood !!
Crossover distortion. I'm so glad this video exists, I would have no understanding of it otherwise. Thank you sir!
The best video for understanding basics of class b and ab
Hoping to watch c d ..etc
More info about the two diodes would be nice... Very nice video, made me understand more about A, B, AB...Thanks !
Am I missing something? In the A/B, D1 means there's no route for the signal to the NPN transistor, right? Only the PNP is going to amplify the what hits Vin.
what is the smallest ac signal these can multiply? what about tape head signals? well under 1mv. is it better to use an actual tape head preamp? ive seen op amps being used.
Shouldn't there be a -Vcc instead of ground to help formulate the output signal?
This is GREATLY appreciated!!
Sweet and short that's great lecturing
Great explanation of these different amplifiers. I used a constant current source top and bottom to get rid of the cross over distortion on a push-pull amplifier similar to the one you in another lesson. Thanks.
Thanks! Where would a potentiometer go to raise and lower gain in the AB amplifier circuit?
You explain these topics well. Thank you!
2:47
Is there not a different type of transistor you can use to reduce the B-E voltage you need to switch it on?
The B-E voltage requirement was because of the silicon material used in the transistor. I assume changing to germanium will lower it to 0.3 but that isn't really practical
Its a great thing, you make those explenation so simple.
how to design class AB amplifier , how to decide value of resistors etc
Interesting how combining the two amplifiers makes for one better one. Checking out Device Plus and looks like some cool little projects there. Thanks!
Glad you enjoyed the video.
Are there videos on the Class C and class D?
Everything is here: ruclips.net/p/PLGhvWnPsCr5_ZYDz7vnI3WApltzQaurlS
Very interesting. Nice series! 👍
Thank you!!
@@learnelectronics
What is the minimum value of the DC biasing current in class A output stage? Explain you answer.
1:52 two parallel transistors you mean :)
Is the crossover distortion present in class A amplifier also??
caso craft
Hi. Nah this isn’t an issue in a class A amp as the transistor is biased (you can tell by the fact that there’s a voltage divider with its output being the base). This means that the transistor is sitting in its active region (switched on, in laymen’s terms) at all times. The required 0.7V is always there because of the voltage divider. :)
In class B what if the signal strength does not reach 0.7V even at peak.
It would have beneficial to everyone if you would have explained how the A/B amplifier removes distortion around zero cross. Was it because of the voltage divider/biasing resistors?
While I've been enjoying these videos, you don't really go into detail about what's going on in the AB. I don't think you even mentioned the inclusion of the diodes in the design. Regardless, I'll keep watching the videos :) Really trying my hardest to understand my new Op Amps class. It's fascinating.
BUT WHAT DO THE DIODES DO???? AGGGGHHHH IT'S DRIVING ME MAD! 🤪! I can't work it out. Each diode drops around 0.7v. why are facing the same direction? I just can't fathom what is going on. Other than that, great video 👍😁
I think what's happening here is that the diodes are blocking flow through them when the wave is high, leading to greater flow through the gate. This is most obvious with the NPN side, but the principle is the same on the PNP side, just flipped upside down. Now, you might wonder why the diode is pointing they way it is on PNP side, but that's because when Vin is in a trough, it's effectively going to have a kind of opposite effect on the PNP transistor and the diode on the negative side of Vin and Vout. What makes this confusing is mainly the nature of AC circuits if you're used to dealing with DC ones.
That's at least my understanding, but it's something I think I'd need to verify in a simulator or in a board.
What are the necessity of the two diodes?
+Sayantan Maiti so as to not backfeed
for the diagram with the class b amp, why do the transistors not turn each other on? (lol) npn turns on if current flows in, while pnp turns on when current flows out (or vice versa depending on physics or electronics), so why dont they turn each other on?
+fredlllll I think you're thinking in terms of DC current. Think in AC only one transistor is on per half cycle, the other half cycle it's reversed biased.
yeah i guess it works when a signal is applied, but what if there isnt a signal?
Thanks for sharing, great vid
Ok, so website "Device Plus" appears to be a sort of techno-gizmo resource - but less of a "build X project" reference. That site links to ROHM via a single icon on the home page. Parts ROHM apparently manufactures are elaborated (with data sheets), and ultimately us DIY'ers are directed to distributors such as Mouser or Digi-key to buy. FWIW.
+Are Jayem uh, ok?
I was bamboozled by the Devices Plus site, thinking it had more "circuit content". The ROHM site appears substantially more useful to makers. Perhaps you will find some unusual devices made by them to evaluate and experiment with. They have speech synthesis and "energy harvesting" products, to name a few. For folk looking for parts, they may want to jump past Devices Plus, and head over to ROHM.
I just spent $50,000,000, and 17 cents'''' on a new scope when I could of got a paper one!!!! where did I put that god dam recite ???? hey,, I could make a scope out of it; ).. loved the video Paul was shouting "very quietly coz its 6:25 in the morning here" when you asked why it distorts.. but you couldn't here me; ) forward voltage drop. the voltage needed to turn on the transistor.. need to go to bed coz im not joking when I say I was getting frustrated that you didn't say yes your Keith.. just goes to show how much I was into the video!...! good night!!
Why r d 2 diodes used ?
Compensation diodes to account for the base-emitter junction voltage drop
But *why* do those diodes eliminate the crossover distortion? You don't explain that ☹️ (but thanks for the video 👍)
thank u so much... superb explanation
Coooool! looking forward to more
What happened to your hand? By the way nice vedio thanx for helping
He have a congestive heart falioure, I think some lipoprotin(cholesterol) level high
At the end of this series you should breadboard each type and output to a small speaker so everyone can hear the differences between them all.
+Michael Padovani I will do that, and no I haven't sent the boards out yet... Life of complicated at the moment
Understood, trust me...hang in there
THANKS A LOT 💯
Very interesting. Thanks.
You still need to bias class b amplifier or you get massive crossover distortion
Why do we need class AB?
Easier on the transistors they only work 50% of the time.
@@learnelectronics
Oh really
@@learnelectronics
OK I have questions
Why do we have two vOmin values in calss A amplifiers?
@@learnelectronics
😷
🙏🏻
Thank you
Efficiency is more than 50% for pure class B, can be as much as 78.5%
Nice!
Thanks
But I was thinking that if there was a real practical on the concepts I would understand even more.
awesome
support
I thought that the B was more efficient than AB
No, the push-pull of AB is more efficient.
learnelectronics I was wrong... thanks
Thanks for the overview. Isn't push-pull synonymous to class B/AB ? What would a non push-pull AB look like. I thought it meant that one transistor pushes voltage up and the other one pulls it down, kinda...
Class B is more efficient, class AB requires bias voltage on the bases of the transistors so the transistors are turned on for longer which gives less efficiency but reduces distortion. Also, class B is push-pull as well.
Those two things are funny looking transformers!
Sometimes I say transformer 2hen I mean transistor. It happens. If it bothers you I invite you to not watch any further videos on my channel. Videos are unscripted and I do say left when I mean up sometimes. But thanks for watchint.
🇳🇱🤔🤔🤔🤔🤔🤔🤔🤔🤔🤔🤔class B amplifiers. are useless ?. and are therefore not used for signal amplifier ???
AB explanation is little.. I didnot undrrstand