Transistor Amplifiers - Class A, AB, B, & C Circuits

Рет қаралды 244,930

Күн бұрын

This electronics video tutorial provides a basic introduction into the Class A, AB, B, and C transistor amplifiers. The class A amplifier is the common emitter amplifier which uses a single NPN transistor. The Class B amplifier using two complementary NPN and PNP transistors and yields a higher amplifier efficiency. The Class AB amplifier uses two diodes to eliminate the crossover distortion that's present in the Class B amplifier. The Class C amplifier is a tuned amplifier with a high efficiency but with extensive distortion.
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BJT Transistors - Electronic Switches:
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Night Activated LDR Sensor Circuit:
• DIY Night Activated LD...
Finding The DC Load Line & Q-Point:
• Transistor Base Bias C...
Voltage Divider Bias Circuit:
• Voltage Divider Bias C...
Collector Feedback Bias Circuit:
• Collector Feedback Bia...
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Emitter Feedback Bias Circuit:
• Emitter Feedback Bias ...
Common Emitter Amplifier:
• Bipolar Junction Trans...
Common Collector & Base Amplifier:
• Common Collector and C...
Darlington Pair & Beta Current Gain:
• BJT Transistors - Darl...
Voltage Gain of Transistor Amplifier:
• How To Calculate The V...
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Multistage Transistor Amplifier Circuit:
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Transistor Audio Mixer Circuit:
• Transistor Audio Mixer...
Operational Amplifiers:
• Operational Amplifiers...
Summing Amplifiers:
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LM386 Audio Amplifier:
• LM386 Audio Amplifier ...
LC Oscillator Tank Circuit:
• LC Oscillator Tank Cir...
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Пікірлер: 122

@TheOrganicChemistryTutor 6 ай бұрын

Final Exams and Video Playlists: www.video-tutor.net/

@miguelmalatechannel3792 Күн бұрын

Why class b are not loud sound? I make it and I tested not loud what's wrong my make

@miguelmalatechannel3792 Күн бұрын

I increase a voltage and amps and same sound not loud?

@hervemarie966 4 жыл бұрын

There is like magic in your voice and explanations, they are clear, precise and the essential is said to allow us to always learn something. THANKS.

@efass6289 4 жыл бұрын

This man has been my messiah for Honors Algebra II, Honors Pre Calc, AP Calculus I and II, Honors and AP Chemistry, and AP Physics... I stan Thank you so much for all of your help, I am now going to Carnegie Mellon as a double major in math and computer science. I honestly think my understanding and love for math has greatly been facilitated by your videos, and I plan to use your videos for college and beyond!!

@efass6289 4 жыл бұрын

@the noah lucario best of luck man! if you're using OCT I'm sure you'll do great

@PunmasterSTP 2 жыл бұрын

How are your studies going?

@user-cy6ez9st2j 3 жыл бұрын

0:17 - Class 'A' amplifier 7:59 - Class 'B" amplifier 11:45 - Class 'AB' amplifier 13:10 - Class 'C' amplifier

@mahjabinbintemannan8924 4 ай бұрын

First year of undergrad to last year of it, you are literally saving my life, be it calculus, linear algebra, your explanation is unparalleled. I was struggling with this topic, i have an exam today, I almost gave up on the topic, and you explained the whole thing to me in 30 minutes. Will always be grateful to your for this quality contents.

@manfredcaranci6234 3 жыл бұрын

Just what I was looking for to assign my class this week. Your presentation is excellent.

@artay9608 4 жыл бұрын

Ever since we went to online classes cause of the quarantine. You’ve helped me a lot. Thanks!

@PunmasterSTP 2 жыл бұрын

Wow, you make this stuff seem as easy as A…B…C…. Keep up the great work!

@Ares-sm8uk 3 жыл бұрын

That one clear, detailed and overall good explanation. Thank u.

@robertismond7788 3 жыл бұрын

Thank you I just recently started tearing apart Old amps ect and building my own circuits ....was slightly getting confused till I watched this great explanation 👍

@RadiantBloom 4 жыл бұрын

Nice video. NPN -Not Pointing iNward. PNP - Perfectly iNward Pointing.

@Octeeve 2 жыл бұрын

PNP - Pointing neutral Point, NPN -Not Pointing Neutral

@gamtogujju 2 жыл бұрын

You are just brilliant and know very well how to explain with so ease, claps buddy!

@robonkenhout7965 Жыл бұрын

Amazing! You're good at this. (I mean the explanations) Many try, few succeed. I saw this exact formula (for Ib) on another video and was a little perplexed. Now, much clearer. Thanks!

@rootuser265 3 жыл бұрын

He just helped me in calculus and now he is here again. Can you do a tutorial of revealing your face? Really appreciate what you are doing, I should ve just paid you $10,000 for tuition fee not college. My college teachers suck.

@dariusaarav2886 2 жыл бұрын

instablaster...

@eggieeeeeee 4 жыл бұрын

JG, I have been watching your video tutorials ,since a very long time. Your videos helped me a lot. But, as your student and fan, I have a request to you.I shall be much grateful, if you make a video, telling us, how you edit your videos, how do you make these tutorials. This is my small request. Have a good day☀.

@amaleltahir8249 4 жыл бұрын

I usually go to these videos to help me with my algebra class.

@KenTeel 2 жыл бұрын

Question: using electron flow (not "conventional current"), looking at the Class B amp at 9:44, the positive going input signal will turn on Q1, which will cause electrons to flow from the ground, through RL, "through" the output capacitor, up through the emitter and collector of Q1, to Vcc. When this is happening Q2 is turned. After this happens (and the input signal goes back to zero), the output capacitor is charged with a positive on the side that goes to the emitters, and a negative (electrons stored) in the side that is connected to the load resistor. When the input signal changes, and goes negative, Q2 turns on and Q1 shuts off. This makes the resistance across the emitter and collector, of Q1, very high (very little current flow through Q1.) As Q2 begins to have electrons flow through it from the ground, up through the collector then through the emitter, the electrons are "pulled" by the positive charge on the capacitor (the plate connected to the emitters,) and electons will flow into the plate of the capacitor that is attached to the emitter of Q1, while the other side of the capacitor (the other plate) will send it's electrons down to ground, through RL. Correctamundo?

@user-ub5su9vj6d 6 ай бұрын

9:55 +cycle Vs -cycle. Great job. Good and clear explanation. 😇😇😇👍👍👍🙏🙏🙏

@Enigma758 2 жыл бұрын

9:44 Any reason a single coupling capacitor couldn't have been used directly past the ac source, and then split off to the two bases?

@rajveerajmani Жыл бұрын

You sir are a SAVIOUR thank you SO MUCCCH!

@kolinevans9127 4 жыл бұрын

Always more to learn lol : D ... Questions With the class C could not one place a resistor at the ‘E’ which would mean that the voltage drop across this would mean that the junction between the E and the resistor will have some voltage in ref to ‘ground’ example 1v , this would then mean the E has 1v ref above the Base if the base is ref to ‘ground’ Another question, could you trace the ‘current flow’ in a basic AB amplifier for amusement and insanity? The only way this device can function {for me} is if the ‘N’ junction is equalized to the ‘P’ junction when they are merged , I.e they effectively became one device with two junctions and a equalized 0 central point that is because the N from the NP>N equalizes with the ‘P’ of the P

@carmelpule8493 Жыл бұрын

The class A amplifier with a resistor in the collector is inefficient because the quiescent bias current without any signal is still passing through "a RESISTOR" and so that is wasted power. Since at the collector the transistor is "a current source" one can short circuit for a DC current and that is what the inductor does, where at DC, it has no voltage across it and so it does not use any power when there is no signal, The useful current is when there is a rate of change in it and so the transformer is used to replace the collector resistor. It should have been noted that his cannot be done in the emitter as at the emitter the BJT is a voltage source and one cannot short circuit a voltage source as one can short circuit a current source. Congratulations for this video , an excellent presentation.

@martinx1783 2 жыл бұрын

I learned more knowledge from this in 17 minutes compared to the 5 hours lecture in my uni

@shaywhoop4040 Жыл бұрын

No kidding, you're a literal life saver

@dartplayer170 3 жыл бұрын

Great explanation however there is a mistake in the Class A analysis. The 25% efficiency for capacitive couple output requires a load impedance equal to the output impedance of the amplifier according to the Maximum Power Transfer theory. You have not included a load. You are correct in saying that the maximum compliance is achieved with Vce = 1/2 Vcc when there is no load. However, when a load is hooked up according to MPT compliance is maximized by making Vce = 2/3 Vcc. An ac load line is required to determine the previous statement. In theory, matching the load to the output impedance of the amplifier provides 2 equal current paths and thus wastes 50% of the efficiency across the Rc resistor. This explains why the transformer coupled amplifier can attain a theoretical maximum of 50%. In Class A mode the transistor conducts for a maximum of 180 degrees and thus wastes at minimum 50% more of the efficiency. Thus, capacitive couple efficiency is >= 50% x 50% = 25% and transformer coupled >= 50%. The extra efficiency losses are due to design problems, loss of power by other components and loss of power in because the linear region of the transistor is slightly less than 180 degrees. That is the saturation and cutoff regions are unusable.

@PoboyMusic 10 ай бұрын

This guy knows about everything.

@RijuChatterjee 3 жыл бұрын

lol I like how he says "coopled"

@RijuChatterjee 3 жыл бұрын

@@AndysRamblings Lol nah it's mostly an isolated quirk of pronunciation nothing wrong with the video

@thething6936 2 жыл бұрын

@@AndysRamblings wouldn't want to do that this man helped me get my distinctions😩

@minhajsixbyte 3 жыл бұрын

great video. can anyone tell me what software is he using to draw

@hamidbesharati3688 2 жыл бұрын

Hi .is it pussible to amplify a fast edge squre wave (rise time=30ns) with 10 Vp-p to 100 Vp-p and with rise time being less than 60ns?

@rickymiravalles2687 2 жыл бұрын

Which class of amplifier design has lower THD or sound clear or best ? kindly enlighten me ty

@peterwan小P Жыл бұрын

WTH...... I was literally searching for informations about audio amplifier on KZfaq and I know you because I used to watch a lot of video from you to help my high school study (like physics and maths) but MAN you literally know everything OH MY GOD ?! you not only shocked but also scared me XD you are amazing, how can you literally know everything ??? man you must have lots of degree OMG XD

@sand0can1 9 ай бұрын

Probably you should mention something about DC biasing and superimposing the A/C signal so that it oscillate around Vb. For example offset 0.2V A/C by 0.8 DC so that compound signal oscillates around 0.7-0.9V

@antonioarin3697 3 жыл бұрын

Can you pls upload a video in AB and B amplifiers circuit analysis. I have a test coming in a day.

@ikhwanmirza402 3 жыл бұрын

Hye, may I ask? How is the working for Class A amplifier without AC input? Now I am doing a mini project, the title is Audio Amplifier for Cell Phone (Class A). Can you help me?

@C-130-Hercules 3 жыл бұрын

Amazing video 👏

@oliverer3 8 ай бұрын

Organic chemistry has really changed since I was in school.

@BharathKumar-kx4kt 3 жыл бұрын

How if we introduce 2diodes how we can reduce the crossover distortion can you explain still

@donniumar767 2 жыл бұрын

FOR CLASS A AMPLIFIRE WHAT YOUR REREFERANCE FOR PSU SMPS OR TRFO?

@musiclyrics1860 2 жыл бұрын

How about the efficiency, if we put transformer instead rc in the output

@JohannY2 4 жыл бұрын

You explain the HOW good, but rarely the WHY.

@lovesoni3169 9 ай бұрын

is this small signal or large signal amplifier? and can I use this method to make a audio amplifier(loud speaker)?

@iaronbartal8393 2 жыл бұрын

whats the function of RB on the last 2 circuits?

@antoniohenriquez8800 3 жыл бұрын

What tool is used to draw on screen?

@fernandohood5542 3 жыл бұрын

Would have been good to explain the biasing on the B and AB.

@jackevans2386 Жыл бұрын

1:31 "coopling capacitors" ?? They are 'coupling' capacitors. ie. They 'couple' the AC signal from the previous stage to the next stage. They don't "cooople"

@abuhenababu 4 жыл бұрын

Good Job

@anastahiliutawala3879 3 жыл бұрын

Thank from Tanzania

@progamermajsc7230 3 жыл бұрын

Can someone explain to me why he puts a negative voltage supply there. I'm new to electronics so I don't know. I just think it's because some positive voltage goes left instead of to base. This means some of that extra positive voltage needs to be cancelled out by going to a negative source.

@hariharan-yi8tf 2 жыл бұрын

How u have knowledge of every field 😯

@lohxinru3021 4 жыл бұрын

Awesome 👏 Your voice is sweet

@shreyaskulkarni9345 Жыл бұрын

1:30 am. Today morning is Electronics exam & I'm watching this ... Like if ur doing the same 😉😉👍🏻

@abulfazibrahimov1990 4 жыл бұрын

Thank you.From Türkey 🇹🇷

@progamermajsc7230 3 жыл бұрын

Can someone please explain what RB and R1 does.

@arbymohamed6136 Жыл бұрын

Thank you

@TheRojo387 3 жыл бұрын

I bet you could replace the diodes with transistors whose base and collector are coupled, on the class B.

@roncaruso931 Ай бұрын

Coupling is pronounced "cupling". I've seen many class AB amps that do not use diodes. The class C amp is used in high level AM final amplifier in transmitters.

@tinkerman9525 4 жыл бұрын

Great video. But a opportunity lost. Should explain it effects on audio and rf. Reproduction of A class amplifier is near perfect reproduction of input. The best. Effieciency is 4000w in 1000w out. Fot rf it is class A , AB (SSB) and C(CW FM) that is always used for comms. 👍👍👍👍waiting for next video.

@arsalanuddin3661 8 ай бұрын

Great Video

@beatlessteve1010 2 жыл бұрын

Coopled?..why is c1's polarity different than c2?

@akabomb 4 жыл бұрын

"coopling capacitor" lol good and informative video though, thanks

@josianemartinez6062 3 жыл бұрын

I also noticed that he pronounces couple as coople. I wonder if his pronunciation is due to some regional accent? Curious.

@danielgaewski8344 2 жыл бұрын

Say coople... one more time..

@amaleltahir8249 4 жыл бұрын

Nice!

@arduinorobot1216 Жыл бұрын

Amazing and super

@bennguyen1325 Жыл бұрын

This guy is the entire university.

@acamphibiousguys2006 20 күн бұрын

What is mean by voltage divider and its use

@laptech3767 4 жыл бұрын

What college did you graduate?

@johsanch5667 4 жыл бұрын

rB in the last ckt?

@markandoyo2204 Жыл бұрын

Which Guitar Amp belongs to the Class type? and which the 88key keyboard Amplifier belongs to the class type?

@uygarglk 3 жыл бұрын

Ah, it says on Razavi's RF Microelectronics Class A has a max effect of 50 %. Why is that?

@abuhasan3726 Жыл бұрын

Nice and cool voice

@etg9080 2 жыл бұрын

Since the class A and Class C are off for negative cycle, does it not half the data could be lost?

@joseph-jamesharding4815 2 жыл бұрын

this guy is smart, i swear he knows everything maths/ science/ engineering based ahaha

@francoisdreesen9684 4 жыл бұрын

With 2'12" left you draw the polarity of signal generator wrongly to put the transistor in cut off!

@dajidmorel2152 9 ай бұрын

How have an amplifier with (Vs/Ve) = 1000 ?

@rx6910 3 жыл бұрын

It's a great explanation, but you didn't show where the speaker + and - should be, also the + and - for input and output. Beginner like me would have difficulties understanding them.

@StinkyEla 9 ай бұрын

how do you know like, everything from chemistry to electronics to psysics and everything

@Greg_Chase 11 ай бұрын

At time 5:30: "...transformer *_C O O P U L L E D_* class A amplifier...." "COOPULLED" - it's supposed to say COUPLED. Not COOOOOO - PULLED I point this out because - apparently, this voice IS SYNTHETIC! They did a really good job with the volume inflections for the words, and for the cadence. This one little error - saying "cooo - pulled" instead of "COUPLED" - was the giveaway. Remarkable how high the quality of this synthetic voice is. The error in the software that creates this voice is easy to fix (I'm a software engineer). Right now, the mistake being made is this: "coupe" is a type of car. It's pronounced "COOP" And the -led suffix is used everywhere: "STUMBLED", "MUMBLED", "TUMBLED", and is pronounced "ULL'D" So the software is mistakenly combining "Coupe" with "ull'd" and pronouncing it "cooo-pulled" I can't believe how good the voice is. I was 100% convinced it was the author of the video speaking.

@mr.decoder4843 4 жыл бұрын

JG please teach about "host guest" & clatharates in organic chemistry

@netx421 2 жыл бұрын

Class a has a sound that is better than the others. I'm not too worried about efficiency but I am in sound quality. You need some larger transistors like a tip122 and use lower voltage like 5 v 1a to power them. Less resistors and no voltage divide just place a 1k resistor or pot between the base and collector for biasing and bam nice little amplifier

@PotatoChips-jy9pk 4 жыл бұрын

How did you know what I was thinking, dawg!?

@kolinevans9127 4 жыл бұрын

My next inclination would be to ask what an ABC amplifier looks like? lol , {I wish I was joking : D }

@antblakeee4177 2 ай бұрын

i don't know how you do it man😁😁

@curtpiazza1688 7 ай бұрын

😊 🎉

@ColocasiaCorm 2 жыл бұрын

Coopled

@johsanch5667 4 жыл бұрын

hello tupvian

@chrislykins4600 8 ай бұрын

Are you mark wahlburg?

@almscliffe 3 жыл бұрын

If you're going to talk about the different classes of operation then the first thing you should do is explain what the differences are, i.e. class A conducts over the full swing of the input, B over just +ve or -ve swing, etc, rather drawing a common emitter amp, complete with bias feedback, and saying 'this is a class A amp'. There are other ways of implementing class A.

@thatdrh 2 жыл бұрын

This guy from the east coast?

@HaDi-xf4vi 2 жыл бұрын

Berapa nilai resistansi resistor

@ediz2000 Жыл бұрын

bro how are you so smart

@Shashwat_raman_shukla 4 жыл бұрын

I thought it's organic chemistry but nvm I'll digest it

@hifiresearch74 3 жыл бұрын

Cold start of Class A - kzfaq.info/get/bejne/hcx0o7Z1q7qxpok.html & Switch off class A amplifier - kzfaq.info/get/bejne/jdymn8ZlnJ-7mI0.html

@17joren 2 жыл бұрын

I enjoy your videos but it’s funny how you pronounce “couple” like “coople” instead of “cupple.” Do you and your partner make a nice coople? Lol

@felixlucien7375 3 жыл бұрын

Is there anything this man doesn't know?????

@thatdrh 2 жыл бұрын

Your NPN let’s ground flow, now positive. Yet your diagrams are showing npn connected to VCC. Unreal…

@shannonroberts5080 4 ай бұрын

Oof, over 200k views here and there are so many errors in this video, particularly in the class B and class AB descriptions.

@rmohand.v3601 4 жыл бұрын

Base resistor must be connected between vcc and base terminal..not between base and emitter. Class B amplifier shown should be called Class B push pull.

@rods6405 3 жыл бұрын

Sorry this is pretty poor explanation your jumping between dc and ac voltages at 7:45 the primary of the transformer is a short cct for DC voltages but a impedance for ac voltages. better explanation here www.circuitstoday.com/transformer-coupled-class-a-power-amplifier