So, I have a sincere question. Maybe I'll sound like a n00b, but logically this makes little/no sense to me (But maybe that's just me). What is the point of the capacitor, when there's a completed circuit as a result of the 1N4001? How does the capacitor help? I honestly don't understand it. I know that a capacitor is supposed to absorb electricity, and when it's full it acts as an open circuit, but if there's a diode (1N4001) that completes the circuit, how does the capacitor help?