Need help finding the current in a basic circuit

[Evy]

Here is the circuit I need help finding a current in. I am seraching for the current through R_L.



R_L = 1k
V_CC = 12V
V_EE = -12V
I₂ = 10mA
R₁+R₂ >> R_L  (they are much bigger than R_L)
There is almost no current through R₁ and R₂

The voltage across R_L is 12V, right? Then current must be 12V/1k = 12mA. And then there is of course the current source that is drawing 10mA current from the load.

Is the total current through the load then 2mA?

[ptricks]

The current through the load doesn't change .
RL is basically a load connected between VCC and ground, everything else in the schematic  doesn't matter.

[ironmonkey]

Short answer: The current source is not drawing current from the load. Try to figure out this first

Enviado desde mi MotoG3 mediante Tapatalk

[Evy]

Is it drawing it from the V_CC then? If that is the case then the current is 12mA, right?

[Benta]

Yes.

[Vtile]

** In these kind of situations it is typically beneficial to redraw the circuit. Ie. for me it is many times hard to understand intuitively these electronic pull-up/pull-down style of drawings, not to mention trying to remember what the Vee,Vdd etc. did mean. Common rule through electrical drawings is that higher voltage potential is top of the drawing, but there is exceptions. The ideal sources can sink or source infinitely of current or voltage to satisfy the given voltage or current, in real life such things hardly exists and there is always some parallel or series components in them.


Edit1. Ugh* Goofed up the image..  Removed.
** Edit2

[Ratch]

Evy,

Obviously, Vcc is supplying 22 ma.  12 ma will be present in RL, and 10 ma in the current source.

Ratch

[Zero999]

Is this part of a larger schematic? If so, please post the rest of it. Otherwise, it doesn't make much sense. What's the purpose of I₂?

Is it a voltage regulator circuit, with V_CC being the output voltage?

[Benta]

Is this part of a larger schematic?

I don't think so. It seems Evy is attending an electronics course and wants us to do his/her homework.
That's my perception.

[Zero999]

Is this part of a larger schematic?

I don't think so. It seems Evy is attending an electronics course and wants us to do his/her homework.
That's my perception.

Here most schools/colleges don't resume until September and presume that's the case for most of Europe, so there's still plenty of time to get it done.

There's also a difference between providing help and support and doing all of the work.

[Evy]

Is this part of a larger schematic? If so, please post the rest of it. Otherwise, it doesn't make much sense. What's the purpose of I₂?

Is it a voltage regulator circuit, with V_CC being the output voltage?

This is part of a bigger schematic. This is what you get when you analyze the two scenarios of which the one is to assume that the transistor in the second stage is a short circuit from this thread. Didn't want to make this thread too long so I stripped the circuit down a bit and removed the unessential parts. Its not the same problem but similar and has other values. I had to calculate where the output clipped in an output stage. In the key of the book the author wrote that the current had to be infinite (when transistor is a short circuit) which I didn't understand and hence, created this topic. I can post the whole problem if someone is interested.

I2 is the biasing source for the transistor in the second transistor stage.

[Evy]

Is this part of a larger schematic?

I don't think so. It seems Evy is attending an electronics course and wants us to do his/her homework.
That's my perception.

I am sorry that I, somehow, led you to believe that I wanted you to do all the work for me, which is not the case. I just want helpful tips and your valuable insight on how I could solve my problems when I get stuck. 

Also, these problems are not part of my homework. But even if these problems were part of my homework/ school assignment I would be allowed to post these in this forum as long as I provide enough information on how I tried to solve them.

NEWBIES PLEASE READ BEFORE POSTING

School assignment questions are ok, but show what work you have done already.

[Zero999]

Is this part of a larger schematic? If so, please post the rest of it. Otherwise, it doesn't make much sense. What's the purpose of I₂?

Is it a voltage regulator circuit, with V_CC being the output voltage?

This is part of a bigger schematic. This is what you get when you analyze the two scenarios of which the one is to assume that the transistor in the second stage is a short circuit from this thread. Didn't want to make this thread too long so I stripped the circuit down a bit and removed the unessential parts. Its not the same problem but similar and has other values. I had to calculate where the output clipped in an output stage. In the key of the book the author wrote that the current had to be infinite (when transistor is a short circuit) which I didn't understand and hence, created this topic. I can post the whole problem if someone is interested.

I2 is the biasing source for the transistor in the second transistor stage.

Actually it would be much easier to follow and you'd get more relevant replies, if you kept it to one thread per topic/circuit, rather than splitting up into many. Creating too many threads, means people lose track of what's been said elsewhere and it stops one from seeing the bigger picture. This seems to be a common error by new people asking for help.

Do all the circuits you've asked for help with recently, refer to the same book? Ideally it should all be in one big thread.

[Evy]

Is this part of a larger schematic? If so, please post the rest of it. Otherwise, it doesn't make much sense. What's the purpose of I₂?

Is it a voltage regulator circuit, with V_CC being the output voltage?

This is part of a bigger schematic. This is what you get when you analyze the two scenarios of which the one is to assume that the transistor in the second stage is a short circuit from this thread. Didn't want to make this thread too long so I stripped the circuit down a bit and removed the unessential parts. Its not the same problem but similar and has other values. I had to calculate where the output clipped in an output stage. In the key of the book the author wrote that the current had to be infinite (when transistor is a short circuit) which I didn't understand and hence, created this topic. I can post the whole problem if someone is interested.

I2 is the biasing source for the transistor in the second transistor stage.

Actually it would be much easier to follow and you'd get more relevant replies, if you kept it to one thread per topic/circuit, rather than splitting up into many. Creating too many threads, means people lose track of what's been said elsewhere and it stops one from seeing the bigger picture. This seems to be a common error by new people asking for help.

Do all the circuits you've asked for help with recently, refer to the same book? Ideally it should all be in one big thread.

Yes. But this one is a different problem (but similar) and I don't need help with the same thing as the other thread. It would be hard for other people with same problem to get any valuable information in the future when they find the problem on this forum, if I had everything in one giant thread. Other, similar, forums usually have 1thread / problem.

[Zero999]

Is this part of a larger schematic? If so, please post the rest of it. Otherwise, it doesn't make much sense. What's the purpose of I₂?

Is it a voltage regulator circuit, with V_CC being the output voltage?

This is part of a bigger schematic. This is what you get when you analyze the two scenarios of which the one is to assume that the transistor in the second stage is a short circuit from this thread. Didn't want to make this thread too long so I stripped the circuit down a bit and removed the unessential parts. Its not the same problem but similar and has other values. I had to calculate where the output clipped in an output stage. In the key of the book the author wrote that the current had to be infinite (when transistor is a short circuit) which I didn't understand and hence, created this topic. I can post the whole problem if someone is interested.

I2 is the biasing source for the transistor in the second transistor stage.

Actually it would be much easier to follow and you'd get more relevant replies, if you kept it to one thread per topic/circuit, rather than splitting up into many. Creating too many threads, means people lose track of what's been said elsewhere and it stops one from seeing the bigger picture. This seems to be a common error by new people asking for help.

Do all the circuits you've asked for help with recently, refer to the same book? Ideally it should all be in one big thread.

Yes. But this one is a different problem (but similar) and I don't need help with the same thing as the other thread. It would be hard for other people with same problem to get any valuable information in the future when they find the problem on this forum, if I had everything in one giant thread. Other, similar, forums usually have 1thread / problem.

I'm not aware of any such rule. All the questions you have are linked, therefore they should be kept together. The function of one part of that circuit depends on another part. It's important to understand how it all fits together.