max said:
I see these terms often, but I haven't seen a description between the
two that I
am comfortable with. Or better yet an example an example of each.
Any help would be appreciated,
max w.
A resistive load passes current in proportion to the
instantaneous voltage. If there is voltage across the load,
it is passing current, regardless of time.
A capacitive load pases current when the voltage across it
changes, and in proportion to how fast it is changing. Any
steady voltage drives no current through a capacitive load.
So resistive loads draw current throughout the time when the
source applies voltage to it. The capacitive load draws a
spike of current when the source tries to step the voltage,
and slows the rise time of the step, if the source has
series resistance.
If the load is a resistance and capacitance in parallel,
then the source must supply both currents simultaneously.
If the load is a series combination of resistance and
capacitance, the capacitor blocks any DC current, and the
resistor limits the current that can be passed during any
fast rate of rise or fall, but extending the time the
current passes, after the step in voltage has stopped
changing. There will be and exponential decay of current as
the resistor drop shrinks, and the capacitor sees the fill
applied voltage gradually, instead of as the source changes it.