More than 3 years after graduating, I am now understanding this. Thank you so much.

Awesome job, I am EE, graduated in 1992 from SVSU, I was feeling a little nostalgic for the those simpler college days when I came across your video and decided to watch. All I can say is that I wished that I had these types of resources available to me when I was learning this material, you did an excellent job, keep up the great work.

Incredible video and explanations. I was able to get past a ton of homework problems thanks to you!

Now this was a great example thank you very much! Bonus I asked my professor and he said he is fine with me making the assumption that Ib is zero if I make that argument you showed me!

Thanks for a very clear and helpful explanation. I now have a much better understanding of how to set up a bias circuit for a BJT, and why a certain amount of "slop" necessarily occurs when calculating actual voltage, current, and resistance values.

Thank you for such a crystal clear explanation of a VDB-BJT.

Excellent presentation, and delivery of material content. Thoroughly explained in detailed information describing the devices characteristics and biasing approaches.

thanks man.. why am i not searching for vids at the first time?? i'm so glad... all the books and pdf.s provide nonsense derivations

thanks David ,you are my true teacher,keep going

Hey man, as a student with their electronics final in 3 days, this is the only video I could find clearly explaining where everything came from and then how to use it in an example. Subscribed!

Great job simplifying this ckt. Thanks for the great job. It does help lots of ppl. Highly recommended

This is an amazing video. The way you explained this made it very easy to understand. Thank you so much!

As I was hovering looking for a perfect solution .. I just saw your the cover photo and I knew my problem is solved.... And guess what am just 4mins I to the video and I have understood everything... Thanks man .... 🔥🤗

love you david, so glad for you

you made this so simple...thanks..

Thanks for making this very *CLEAR* plain English video. I can definitely understand your Canadian English.

Congrats! You are antes excellent teacher!

Excellent explanation. Infinitely more helpful than a university professor

Great video! Addresses some of my longstanding questions. Thank you!

Great explanation sir! Now I understand what's going on there

Thanks so much . Your video has clarified all my doubt. Thanks once more

The best video i've seen so far, thank you.

Thank you, engineer, can we use it in the transmitter circuit for the of oscillation?

The "short-cut" method calculates the quiescent collector current and dc bias points of a transistor that has infinite β. The stability of the dc bias against changes in β depends purely on the relative size of the emitter resistor Re. That resistor provides negative feedback that stabilises the operating points as well as reducing the distortion of the stage. It comes at the cost of lowering the voltage gain of the stage, which is 3 in this case. It also "absorbs" around 2.5V of the potential output swing. You can improve the performance of a common emitter by removing some of the negative feedback from the emitter resistance by lowering it, while providing a feedback path from the collector to the base. In other words, derive your base voltage bias (the positive end of R1) from the collector rather than the positive supply rail. Since the emitter resistor only needs to be more than 10 times the dynamic emitter resistance of the transistor (25mV/Ic) to provide reasonable linearity, the emitter can be usefully biased to as little as 250mV above ground, putting the base at about 900mV above ground. If you assume that the collector bias point is around half the supply voltage, you can quickly calculate the ratio of R1 to R2. Knowing the β will allow you to make R1 || R2 less than 1/10 of β.Re for any value of Re. That shows you that the input impedance of the stage is inversely proportional to the collector current, and (all else being equal) you should choose Ic to obtain whatever Zin is required. Somewhere between 1mA and 2mA with a β > 250 or so will result in an input impedance around 5K to 10K. That solution will allow reasonable gains of around 20 to 30 with good stability and linearity, while maintaining independence of transistor parameters. I recommend it to you.

Please add more examples sir for this specific topic because we really understand your explanation. Thank You Sir :)

This video helped me understand the biasing of BJT. Thanks a lot sir!

Very clear explanation!

Finally someone that made me understand this theory. Thanks a lot.

explained very clearly thankuu

very comprehensive and well explained.

Thanks for the good video. How would you solve the question if there is also a resistor between base of transistor and opposite node? Thanks

Thank youu..............clearly explained

Great Work!

Best explanation

Hye. What is the software that you use to make this tutorial?

bless you sir. Great video

Awesome job :D

Thank you very much Sir..

How does the early voltage affect Ic in this type of calculations?

Thank you for this explanation, how do we define Beta here?

how if i want to find the R1 and R2 while i know the the Vce?

Thank you very very much Man!

I think you are one of the best teachers ever! Please make more videos related to EE courses. Thanks. GOD BLESS YOU!

Only complaint is there is not a download link for a pdf document of this lecture. The information is so good there should be a link.

Very useful methode

Thank you so much

Thankuuuu sooo muchhh for thiss😍 thankuu

Great information. I'm in the process of refreshing my basic knowledge of electronics so I might be able to go further in depth. Q. Do you have videos on logic circuits?

Does it make a difference if the upper side is wired not the lower ?

Thanks a lot sir

You're a legend

Thanks for sharing...

What if there's a -VEE voltage source? How should I apply thevenin to it?

So (Rth) is the same as the resistance at the base of the transistor so (Ib) times (Rth) will give me the voltage at the base of the transistor and therefore will give me the voltage at the resistor going to the ground (Rb2) does that sound right?

Thank you!

for Vth why can U disconnect the Rc ?

thnx bro u r amazing

Good video. How do you draw on the screen?

Is the Beta still in effect , even with the 10 times rule

Thank you

the bais is stable ...but what about the ac signal to be amplified later...re usually bypassed by cap ..so the ac does not see re ...which means that amplification depends on the beta which may enlarge the amplification till saturation of cut off??

Thanks a lot From iraq 🇮🇶

I think you should clarify that the Thévenin resistance and voltage are taken from Base to datum node (GND). Otherwise it seems like you are doing 2-port analysis on just one point, the base, which obviously doesn't make sense. Other than that, great vid.

What would I do if R1 and R2 values ain't given?

this is a great example but how do you find Ib if RE is not given?

How you calculate the value of R1,R2,R3,R4?

Could you please explain how you calculate R(th) as being 8.33 KΩ ?

thank you

What is the use of RE in the circuit?how it provide stability?

How do you determine the beta value? From my understand is this an assigned value within the circuit or is it derived from certain equations?

8:16 could you explain why Rth +(b+1)*Re rather than Rth +Re. thanks

Can anyone help with Deriving the equation at 4:44?

Is it Really the same ?? With the new circuit u drawn ,I1=Ic same generator wich is nit true ?

thx a lot bro

If i use exact method even if bre>>10r2 then is it right

Thanks Alot

Just awesome explanation sir, thank you so much for that video. I have one doubt about beta, how can we take the beta value as constant because in any transistor data sheet the beta value have a range. For example BC548 has a beta range from 110 to 500. So which value should i take while using this transistor for amplification (for a perfect active region). Please explain sir, if possible.

Whats the value of i1 and i2?

Sublime!

How do you apply the voltage divider rule there? We should considerate both resistor are subjected to the same current because Ib is very small? Or should we assume that transistor is operating in the cut-off region?

Also is (Vth) the same as (Vb) the voltage looking into the base of the transistor?

How are those resistors in parallel? Having a little trouble getting my head around that

Thanks for the video. I've gained a headache.

Can the resistor 'Re' be equal to zero in this circuit?

how to find Vc and Vbc

What is the equation to solve for ro? Anyone

Or is beta just the Ic / Ib?

how did u get the value of vbe

Wow!! Thanks..

Great

i have a similar problem with no mention on β, how can i solve it with-out it?

Sir how to get answer uA please tell me i don't uderstands

how did you calculate Rth ! 7:20

wheres the part 2 of your AC Analysis of BJT?

how to solve for IC if the beta is unknown? plss help

Is the Thevenin Eq. Voltage the "Base Voltage"?

good guy

hey, how do you reach the assumption that beta*RE>=10R2

what is that || at RTH ?? how did you get 8.33k ?

why u add 1 to beta in 8:14 ?