The Transistor as an Amplifier - Emitter Follower, Common Emitter Circuit, Design Example

[@ife.tugraz]

This video is part of the first course of our *ElectrONiX* massive open online course (MOOC) series. You can sign up for the course *ElectrONiX - Amplifiers* for free on the following links: English: imoox.at/mooc/local/landingpage/course.php?shortname=amps&lang=en German: imoox.at/course/amps Bosnian: imoox.at/mooc/local/landingpage/course.php?shortname=amps&lang=bs

[@Inndjkaawed2922]

This is gold. Thank you

[@ife.tugraz]

Thank you for the nice feedback. We are glad you like it :)

[@kabandajamir9844]

The world's best teacher thanks

[@ife.tugraz]

Thank you, we will pass your feedback on to Michael.

[@assabjorn]

Weary good explaining 😊

[@floretion]

These are awesome tutorials- thank you!

[@ife.tugraz]

Thank you for the nice feedback. You're welcome ;)

[@Yorumcu63]

Great video

[@robertpearson8546]

Is it true that current-controlled transistors are better than voltage-controlled transistors by a factor of beta? At Texas Instruments I worked with I²L logic (Integrated Injection Logic). Beta was about 4, as opposed to discrete transistors with a beta of 200.

[@acermacacermac2677]

At 7:30 is it Zin>=10*Zout?

[@ife.tugraz]

Yes, you're right. We noticed that mistake too late...

[@joshua7015]

This comment should be pinned or make an edit in the description

[@boonedockjourneyman7979]

Ty

[@VishwaAbeywardana]

hey what we get by beeta times output impedance and 10 times output impedance?

[@floretion]

You get a stupidly phrased question.

[@caprisundad]

Fantastic

[@ife.tugraz]

Thank you for the nice feedback :)

[@amjadtrablsi4051]

great

[@SamuelSampayo]

At 10:07 Rb value is 750k ohm but at 10:19, 10 times Rb is 75k ohm, why ?

[@gabrielhomoly8981]

I think that might be a mistake there. For voltage divider in general the conencted load shalll have at least 10x the resistance of the divider resistance. That means R1||R2

[@BoxingDayAC]

Yeah it should 10 * (R1 || R2)

[@rahmatrad4599]

hi thanks for sharing your knowledge, could you please make a video how to read and learn block diagram

[@ife.tugraz]

Thank you for your suggestion. We will put this on our loong list of planned tutorials. Do you have any concrete questions regarding the block diagrams at the moment?

[@kamleshchavan7451]

Sir R2 value how did you get it please explain , I didn't get it explained in the video

[@georgeh1352]

You know that R1 =139k, Vin = 15v, Vout = 8.1v so use formula ; Vin x R2/(R1 + R2) = Vout. Transpose formula to get; Vin/Vout = (1+ R1/R2). Transpose further to get; Vin/Vout - 1 = R1/R2 again transpose to get R2 = R1/(Vin/Vout -1), which equals 163.5k. Select nearest listed value of 150K.

[@cheetah5677]

​@@georgeh1352how to get 1/1.17 value.can you please explain

[@UNKNOWN-gs2xi]

nice

[@ife.tugraz]

You're welcome.

[@ajj7794]

why is the R1 and R2 in parrelle for the impedence of 75K

[@ife.tugraz]

Thank your for your question. We suppose you are talking about the input impedance of R1||R2 at 10:15? R1 and R2 can be seen to be in parallel in the small-signal analysis as the positive and negative supplies are constant and are therefore both on small-signal ground. If you want to know more on small-signal analysis we recommend you to watch the following videos: Basics of small-signal analysis: kzbin.info/www/bejne/enyzooGHaKiNb6s Similar example: kzbin.info/www/bejne/m2GZaKyJfqxmnbs

[@ajj7794]

@@ife.tugraz thank you

[@mtryambon]

Don’t get it. You have an input open the valve but it’s not amplifying. The higher current is already there. I was expecting the low input current being amplified to produce higher output. Like a guitar signal in and a jimmy Hendrix out. But on your example this is not the case

[@welissonsantos5502]

I need a circuit designer urgent