Sketching Voltage and Current in a Double Source Inductor Circuit

[Duave]

Homework Statement

#1 Sketch the total source Voltage as a function of time for -∞ < t < +∞
#2 Sketch I(t) for -∞ < t < +∞
#3 Sketch V_L for -∞ < t < +∞

Homework Equations

In the circuit, there exist a step source, and a constant source. I couldn't find any examples on the web to refer to when plotting graphs for these double source circuits.

So, I don't have any relevant equations.

The Attempt at a Solution

The simple inductor circuit has been uploaded along with a sketch that attempts to answer #2, and one that attempts to answer #3. I don't know how to sketch for #1.

The uploaded photo for #2 has a vertical i axes, and the uploaded photo for #3 has a V_L axes.


Are these curves satisfying the sketch request?
What curve could describe #1 well?

 

[gneill]

It would appear that the total source voltage consists of the sum of the two voltage sources shown in your diagram. Only one of them changes value at time t = 0. So, what should be the value of the total source voltage for times less than zero? How might this affect your your plots?

 

[Duave]

It would appear that the total source voltage consists of the sum of the two voltage sources shown in your diagram. Only one of them changes value at time t = 0. So, what should be the value of the total source voltage for times less than zero? How might this affect your your plots?

Could this be the plot for the source voltage (the one at the bottom in the illustration). The combination of a step and curve?

 

[gneill]

Could this be the plot for the source voltage (the one at the bottom in the illustration). The combination of a step and curve?

No, both voltages sources should be considered as ideal sources, so they will be rigorous in their adherence to potential difference. What that means is, the source V_o will have value V_o for all time, while the source V_sU(t) will go from 0V to V_s volts at t=0. They are ideal, so nothing can make them take on anything but fixed potential differences --- i.e., no curves! Straight horizontal lines only for the total source voltage...