However, I'm confused about the negative bias region (modeled by the bottom left corner resistor/source combination). If the anode of a diode has positive voltage with respect to the cathode, why isn't the resistor/source combination modeled like this?
I feel like I'm missing something really fundamental here.
Thank you for your help
EDIT to include further questions requiring clarification:
(1) Using the forward bias diode model. If I use a positive voltage (1.6V) source greater than the "turn-on-voltage(0.6V)", I get a positive (clock-wise) current which is the same as the value given in the piece-wise linear diode model graph.
However, when I use a Voltage less than the 0.6V "turn-on-voltage", I get a negative current. What is this negative current telling me?
Also, assigning a voltage of -7.2V and using a clockwise current loop. Why do I get a value of -110mA when I should be getting -100mA according to the graph?