# Common Collector and Darlington Circuit with Feedback Potentiometer

#### window789456

Joined Oct 17, 2018
4
My goal is to determine the DC Load Line.

This is the last problem in the workbook and I haven't encountered any problem that has feedback potentiometer. How do I find the input current and the output current?

#### Attachments

• 578 KB Views: 21
Last edited by a moderator:

#### ericgibbs

Joined Jan 29, 2010
17,131
hi w,
E

#### crutschow

Joined Mar 14, 2008
31,490
You determine the relation between the base voltage and the emitter voltage, which then allows you to calculate the emitter current in terms of the position of the two pots.

Last edited:

#### WBahn

Joined Mar 31, 2012
28,148
My goal is to determine the DC Load Line.

This is the last problem in the workbook and I haven't encountered any problem that has feedback potentiometer. How do I find the input current and the output current?
What current are you defining as the input current? As the output current?

What, exactly, is it you are trying to solve for?

#### Ramussons

Joined May 3, 2013
1,330
Keep in mind that the Emitter Pot has a capacitor connected.

#### Papabravo

Joined Feb 24, 2006
19,825
There is no Darlington transistor in your diagram. The two pots allow you to set the input bias point, and the amount of emitter resistance that is bypassed.
One end of the DC load line is at Vce = 15 volts. In this condition the transistor is cutoff. Where is the other end? It is where the transistor is in saturation. Where is that?

#### MrAl

Joined Jun 17, 2014
9,757
My goal is to determine the DC Load Line.

This is the last problem in the workbook and I haven't encountered any problem that has feedback potentiometer. How do I find the input current and the output current?
Hi,

You are seeing some questions coming your way because there are different ways to analyze circuits with transistors in them.

My question is, what kind of model do you normally use for the transistor(s) in transistor circuits?
This is important to know so we know what you are expecting by way of the analysis to come.