A question about the capacitor.

I have always known that the capacitor blocks DC and passes AC current.
However in the Capacitor discharge graph
**broken link removed**
This doesn't seem like AC to me, I'm guessing there's another discharge from the negative pole of the capacitor that is connected to ground, that is why it is not in the graph?
I know I could be completely wrong, it would be great if someone clarified it for me.

Wall-ED said:

I have always known that the capacitor blocks DC and passes AC current.
However in the Capacitor discharge graph
...
This doesn't seem like AC to me, I'm guessing there's another discharge from the negative pole of the capacitor that is connected to ground, that is why it is not in the graph?
I know I could be completely wrong, it would be great if someone clarified it for me.

Click to expand...

The plot you posted is that of a 1 Farad capacitor discharging through a 100 Ω resistor. The equation of the Voltage vs time is the familiar V(t) = Vo*exp(-t/RC), a decaying exponential. t is in seconds (not minutes)

I have modeled this circuit where I charge the capacitor to an initial voltage of 300V.

If we define τ=R1*C1 = 100, then the discharge curve would be the same for any values of R1 and C1 where R1=τ/C1. So for example if R=1meg, and C1 =0.01F (100uf), the discharge curve would be the same. See my plot. I offset the red plot so you could see it...

Just to clarify, as Mike noted, this graph is the discharge curve of a capacitor initially charged to a DC voltage. It has nothing to do with coupling an AC signal.