Someone please assist. Thanks

look image..Without applying signal yet, TS wants node "das" to be 2.5V and 100mA..
so there is 0.2V across R4 and R5 (weird resistor values yh)

0.2V across both so have to make sure 0.2V across R2 for this to work

Also, notice R6 is also connected to node das

Question now is, as TS increases R6, expecting little current to flow through R6 (so it has no effect on R4 and R1) so das should be getting closer and closer and closer to 2.5V. das increases but it also passes 2.5V : can not understand why it passes 2.5V


2nd question (off topic ? no!!!: More important than 1st question)
Please how to remember electronic things? have seen more than 10 transistor topology and can remember most at the moment but fear will forget them in the future and also want to know alot more (like 500 "topologies"?)..How can TS learn them but more importantly, not forget them?
Keep notes and read as often?


Thanks thanks thanks thanks thanks!!!!!!! Love this forum

 

The value of R6 is selected to provide enough base bias current to Q1 AND it provides AC and DC negative feedback from the output transistors.

 

The value of R6 is selected to provide enough base bias current to Q1 AND it provides AC and DC negative feedback from the output transistors.

Yes..foolish me

Increase R6 then less current to the base and makes it turn off

Thanks

You can answer my 2nd question?

 

I learned about transistors many years ago and never forgot it.

 

Different people learn in different ways. As to learning, one thing I do remember from college is that unless you use it you lose it. The typical retention of unused knowledge in just 2 years is less than 10%. Kinda bad average for an expensive college education. However, if you regularly use and apply that knowledge it goes up to about 80% retention for after 2 years. For me it's notebooks. One learning method is called SQ3R. Scan the material generating Questions. Then Read the material thoroughly, Reread the material and you will be surprised at what you missed the first reading. Then Review the material before testing or doing chapter problems. I'm a notebook guy. It makes me slow down instead of skimming along saying to myself, yeah yeah I know that. Read it and synopsize it in your notebook for review later. The process of condensing it into a synopsis helps you to solidify your understanding of the material. You can't explain it if you don't understand it.

 

We only have 3 amplifier topologies.

Q1 - Common Emitter Amplifier.
Q2, and Q3 are Emitter follower (Common Collector Amplifier)

And the diff amp can be viewed as CC + Camplifierier.

CB - Common Base
https://electronics.stackexchange.c...hift-in-cc-and-cb-configuration/411171#411171

 

We only have 3 amplifier topologies.

Q1 - Common Emitter Amplifier.
Q2, and Q3 are Emitter follower (Common Collector Amplifier)

And the diff amp can be viewed as CC + Camplifierier.

CB - Common Base
https://electronics.stackexchange.c...hift-in-cc-and-cb-configuration/411171#411171

Topology not the right word then
Anyways, since you want to be pedantic I attach your circuit for you
will TRY to tackle

 

Please how to remember electronic things? have seen more than 10 transistor topology and can remember most at the moment but fear will forget them in the future and also want to know alot more (like 500 "topologies"?)..How can TS learn them but more importantly, not forget them?
Keep notes and read as often?

My answer is NO !!

It is not a matter of remembering or reading or forgetting....The most important thing is to UNDERSTAND .
(Example: Many many people have learned that the BJT would be a current-controlled device - they simply believe that the relation Ic=B*Ib would explain everything. But that`s wrong! It is a misinterpretation of Ib=Ic/B. If you try to understand the control mechanism of the BJT and if you are able to analyze and evaluate some circiit properties correctly, you can convince yourself on voltage control).

 

The amplifier circuit with many current sources seems to be missing current limiters at the output and a clipping indicator.