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Aren't LEDs fed with DC? If so they would obviously not flicker but I'll admit not cracking my LED bulbs open just to see, as they're expensive enough.
by lloeki 15y ago
Aren't LEDs fed with DC? If so they would obviously not flicker but I'll admit not cracking my LED bulbs open just to see, as they're expensive enough.
- meatmanek 15y agoLEDs are generally fed with DC, as current only flows in one direction, but they flicker as the power coming into them fluctuates -- the more ripple, the more flicker. Cheap LED holiday lights don't even bother rectifying the AC voltage across the lights, so they are only on for half the cycle, giving them a very noticeable flicker. It's especially apparent as you scan your eyes past them. In contrast, incandescents allow current to flow both directions, and will glow for a little while after current stops flowing, so they don't appear to flicker on 60/50hz mains current.
- dredmorbius 15y agoLEDs are DC. What I've observed in certain applications, particularly LED taillights/brake lights, is a flicker pattern which I suspect is either an AC/DC conversion artifact, or a brightness regulation. I find it quite distracting. It's also fairly well known that LED's response to voltage variation is fast enough to be of concern in highly secure data environments. Demonstrations have been made of reading line signal from modems, and even Ethernet and other high-bandwidth networking equipment status/indicator lights.