Understanding Variable Loads in Circuits: Solutions & Verification

[Duave]

Homework Statement

Question 1: For the circuit below, determine what happens at maximum resistance when varying the 10K (decade box) variable load.

Question 2:Explain the answer to the previous question, in terms of voltage compliance of the current source.

Question 3:What causes detectable variations in output current as the load is varied within the compliance range.

Question 4:Verify the explanation in the previous question, by making use of diagrams.

https://scontent-a.xx.fbcdn.net/hphotos-frc3/t1.0-9/10169340_10152051867080919_2806929430313118200_n.jpg

Homework Equations

No equations

The Attempt at a Solution

Solution 1:
At maximum resistance, the saturation is reached, and the diode does not work properly anymore, as the collector current begins to drop.Solution 2:
At maximum resistance, the collector current and the emitter voltage will change from being 1mA, and 1 V, respectively.

Solution 3:
The detectable variations in output current are the due to the the ammeter's installation into the circuit.

Solution 4:

In the diagram below, the top figure is actual data collected from experiment, and the lower image is a theoretical model of how transistors function. The similarities can be seen.

https://fbcdn-sphotos-c-a.akamaihd.net/hphotos-ak-prn2/t1.0-9/10301071_10152051925355919_7760044223328917828_n.jpgAre all four of my answers correct?

 

[NascentOxygen]

At maximum resistance, the saturation is reached, and the diode does not work properly anymore, as the collector current begins to drop.

Diode?

At maximum resistance, the collector current and the emitter voltage will change from being 1mA, and 1 V, respectively.

Where did these values come from?

Are you given an approximate value for β?