# Voltage divider bias

sophiecentaur
Gold Member
"If you dont know anything please don't reply."
I know that I have a lot to learn.
I know that answers don't always come in the form I should like.
I have learned to figure things out for myself when the answers aren't given to me on a plate.
PS I don't have to accept impoliteness. Your responses have been impolite and over demanding.

You and that guy were the one who went arrogant and starting mocking at me that i did not know the basics.
If you dont know anything please dont reply.
p.s Accept things
Sudar-
I am not trying to be arrogant. You need to understand basic dc electrical circuits; voltage sources (power supplies), volts, amps, and resistors. Then you need to understand basic solid state device concepts. In my case, I was educated when vacuum tubes were popular, and my understanding of cathodes, grids, plates, and space charge helped me understand npn transistors. Please review the voltage divider in my post #7. See
https://www.physicsforums.com/attachment.php?attachmentid=23038&d=1263409258
Electrons are flowing out of the base into a voltage divider. The positive base-emitter bias is causing electrons to flow from the emitter to the collector. This is very similar to electron currents flowing out of a hot vacuum tube cathode to the plate, and being controlled by the grid..

Bob S

Averagesupernova
Gold Member
Wow! This is amazing. Sudar, so far all you have told us is that you don't think a voltage divider biased transistor can have base current. After all, that IS the whole premise of this thread. I started out by asking you why you thought that it didn't have base current and I was accused of giving a one-liner. I tried to explain that I would like you to answer my question in order to suitably explain to you why the base DOES have base current. The only thing I got was from post #8
But we dont have a positive voltage applied at the base.
.
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I then tried to explain in post #10 how there can be base current. In post #11 you said
Please explain the concept of voltage divider .
. But in post #18 you said
I know how a voltage divider works without a transistor.
But with a transistor i cant understand it.
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At this point I assumed that you didn't truly understand voltage dividers since you had several oppurtunities to give me an answer to what the voltages would be in the circuit without the transistor inserted and you have yet to do that. I know what they will be, there is a good reason I picked the values that I did.
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In post #21 I got a bit testy with you again. I was trying (and still am) to get you to understand why you are not getting the help you seek.
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In post #23 you said this
But i am sure that you dont know anything about electronics . You have till now blabbered some rubbish not answering to the point and simply finding fault in me. Actually the truth is you dont know the answer and you cleverly managed to escape by critisizing me . Thats all you did throughout this thread. You yourself see what you have contributed in this thread. SImply one line answers and that too you were asking me something else without answering my question. If you dont know anything please dont answer. You are an empty vessel thats why you make noise.
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Now this is downright funny. In post #10 I explained to you how there can be base current. But apparently you haven't accepted it. Not sure why. In post #15 I didn't really explain anything but told you that you may be able to understand it easier if you remove the transistor from the schematic and calculate the voltages then. Not sure if you have or not, but I haven't seen any values come from you concerning this so I am still assuming you don't know.
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Yours truly, The Empty Vessel.

Sudar dhoni,

Enormous numbers of circuits like the one which is under discussion here have been made. They have been analysed, either the hard way with pencil-and-paper, or more lately using tools like PSpice. They have been built, tested, used, and sometimes repaired.

In all of this, the engineers and technicians involved have been able to use the accepted circuit models to obtain workable solutions. There is nothing speculative about this, and really I find it hard to see how you can simply deny that a current flows.

Perhaps I should stop following this before my brain goes into saturation!

sophiecentaur
Gold Member
I have my own mental image ('profile') of this guy. There are lots like him and they all want it 'their way'. They all display scientific naivite, then arrogance followed by petulance and then rudeness. If they drive in the same way - they will likely get punched on the nose by some neanderthal who they will manage to upset.
On the other hand, WE manage to be SOOO civilised about it!
My only consolation is that they mostly grow up into reasonable adults in the end.

Averagesupernova
Gold Member
I have my own mental image ('profile') of this guy. There are lots like him and they all want it 'their way'. They all display scientific naivite, then arrogance followed by petulance and then rudeness. If they drive in the same way - they will likely get punched on the nose by some neanderthal who they will manage to upset.
On the other hand, WE manage to be SOOO civilised about it!
My only consolation is that they mostly grow up into reasonable adults in the end.
LOL. Yeah, we can't educate EVERYONE, we need the neanderthals to remind some folks they are not 'all that'. Seriously though, if sudar comes back with something besides 'you haven't told me the way I want to hear it', I'll have more input if it's accepted.

sophiecentaur