You are making 2 errors as far as I can see. My previous post, which you seem to have ignored, pointed out the first one.

BTW, I get 4.12V when I do the calculation.

Bob

I'm sorry. I wasn't ignoring your post. I just thought your post was delayed as I thought you were referring to what WBahn had posted:


Which I attempted to use in my recalculations:


Please explain the two mistakes that you see. Thanks.

 

Okay, that is the correct formula. What did you get for Ve?

Bob

 

Okay, that is the correct formula. What did you get for Ve?

Bob

My current calculations are in post #18.

 

Why do you think that the Vcc is equal to +20V?

 

Why do you think that the Vcc is equal to +20V?

For that value I wasn't using WBahn's diagram. I just have Vcc as the voltage across the whole right side.

 

But in your circuit, the Vcc is equal to +10V not 20V.

https://electronics.stackexchange.c...oltage-based-on-reference-nodes/392063#392063

 

ElectroJake....did you read my contribution in post#4?
Just as an exercise for you:
Are you able to find the base voltage (referenced to -10V) under the assumption that there is no base curent IB into the transistor? THIS is a good starting point. And - have you a good and realistic guess for the base-emitter voltage VBE? If yes, you also know the emitter voltage VE and you can use Ohms law for finding the emitter current.

 

For that value I wasn't using WBahn's diagram. I just have Vcc as the voltage across the whole right side.

Are you using internet?
There is a lot about transistor stuff.
But you should start with what is a transistor how does it work. Current flow, amplification and it's behave in a circuit.
It's simple but you should remove the unwanted information like the two voltages ( +10V and -10V) hence your circuit is facing 20V.
Regardless of a central zero this has no effect on the currents flowing in your circuit.
If you find X Volt over The emitter resistor then it's X volt over the that resistor regardless the connected + and - 10V.

Please read http://www.learningaboutelectronics...calculate-the-base-current-ib-of-a-transistor

It is handy draw all the currents in the resistors and transistor legs and name them.
Next step is to produce the formulae for each current and or voltage.
Do not use values keep it to the dimensions.
The trick: working out your formulae should produce a dimension like current, voltage or factor.
If you where looking for a factor and the answer has a dimension( like Volt/ current m/s whatever) the formulae is wrong.
Eq a factor could be current / current r/r V/V
But wen you end up with voltage / current is no factor but resistance so formulae in error.

Picbuster

 

Hi,

So i guess you are allowed to handle the transistor as a current controlled current source?
Sometimes you are, sometimes you arent.

 

Hi,

So i guess you are allowed to handle the transistor as a current controlled current source?
Sometimes you are, sometimes you arent.

MrAl - I agree to the second sentence.
Normally, each reader of this sentence (in particular, all newcomers) should immediately ask:
What does this mean....."sometimes" ?
This would open an interesting discussion about engineering principles and rules.

 

MrAl - I agree to the second sentence.
Normally, each reader of this sentence (in particular, all newcomers) should immediately ask:
What does this mean....."sometimes" ?
This would open an interesting discussion about engineering principles and rules.

Hi,

Yeah it depends on the context of the problem.

 

Are you familiar with Thevenin and superposition theorems? They are helpful in these types of circuits.

 

He knows how to solve the problem. What is causing the wrong answers is sloppiness about signs (+ or -) and using inconsistent references for voltages.

Bob