I am studying for my ham radio extra license and AAC Vol II, AC Circuits has been invaluable for me. It is quite clear including the math but I am frequently puzzled how reference points are established.
For example, in the following figure, it makes perfect sense that the AC source Et defines the vector angle of zero:
In the next Chapter on Series RL it is explained clearly why inductor current lags behind voltage but the reference point used in the figure is not-intuitive.
Since Et = El why isn't the AC source voltage phase still the reference point at zero degrees? If displayed this way then the inductor current [tex]I_{L}[/tex] lagging by 90 should be at -90 angle. Leading should be postive anmd lagging should be negative angle with respect to the AC source E and I phases. As I look ahead to more complex circuits, I want to avoid rote memorization and have a more intuitive feel to understanding how mixed circuits work. I must be missing something obvious if these are the teaching standards used? Can anyone offer some advice?
thanks
Jerry K1JOS
For example, in the following figure, it makes perfect sense that the AC source Et defines the vector angle of zero:
In the next Chapter on Series RL it is explained clearly why inductor current lags behind voltage but the reference point used in the figure is not-intuitive.
Since Et = El why isn't the AC source voltage phase still the reference point at zero degrees? If displayed this way then the inductor current [tex]I_{L}[/tex] lagging by 90 should be at -90 angle. Leading should be postive anmd lagging should be negative angle with respect to the AC source E and I phases. As I look ahead to more complex circuits, I want to avoid rote memorization and have a more intuitive feel to understanding how mixed circuits work. I must be missing something obvious if these are the teaching standards used? Can anyone offer some advice?
thanks
Jerry K1JOS