I bought these LED things without realizing they require 220v (I assume that's for European mains wiring, right?). Anyway, I took them apart, and inside is a disk type LED, with a resistor, and a capacitor. The resistors were all 1000 ohm resistors, but the capacitors all had slightly different writing on them.
CARLI MTF 104K 450V 4E30 A02,
CARLI MEH 104K 400V 5B27 A02.
I took the capacitor and resistor off of one of them, and it runs fine on 5v, I tried it with no resistor, 10ohms, 100ohms, 220ohms, and 330ohms. All worked fine, obviously each was a little less bright, but my concern is ruining the LED if I don't use the correct resistor/capacitor with the new voltage.
I'm quite new to this kind of thing. Usually I use regular 5mm LEDs, and I put either a 220ohm or a 330ohm resistor with them (no capacitor).
My question is, what resistor should I use with these LEDs to make them as bright as possible, but still safe from destroying them? Do I need a capacitor?