Load Line technique to intersect two dynamic electrical components?

[killingtime]

Hi,

Is it possible to use the load line technique to work out the current in a series circuit comprising two dynamic components?

The load line method is normally used with one dynamic component and a linear component like a resistor. Example below.



The only examples I can find on-line are for the above scenario. Nothing for two non-linear components.

The resistive component isn't plotted as originating from the zero point, but starting from Vdd and mirrored around Vdd/2 on the x axis.

If the linear component is replaced with another dynamic one would the same method work? Example below:



In the above example we have an incandescent bulb in series with a battery and a constant voltage source (a charger).  I understand the VI curve will vary for the battery as it charges, but I'm only interested in the initial battery state (discharged) which means I can work with one VI curve for that component.

I've plotted the VI of both on the chart below. Blue line is the incandescent bulb. Red is the battery. Green is is the battery mirrored around Vdd/2 given Vdd=14.4v, so the mirror point is 7.2v.

Maths as follows:
Battery starts to draw current at 11.0v
Vdd/2 = 7.2
11 - 7.2 = 3.8v
7.2 -3.8 = 3.4

So the mirrored battery plot starts at 3.4v, and that would put the current at around 0.55A which is where the plots intersect.



Thanks.