Incandescent light bulbs are officially banned in the U.S.::America’s ban on incandescent light bulbs, 16 years in the making, is finally a reality. Well, mostly.

  • @[email protected]
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    1111 months ago

    Yeah, many of those christmas lights use pulse width modulation to control brightness and it is very noticeable. I hope that gets changed over for an analog voltage dimmer soon.

    • @[email protected]
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      511 months ago

      Also, cheap ones run directly on AC, so they flicker at 60 Hz (50 in Europe) because the current is only flowing for half the cycle.

      • @[email protected]
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        111 months ago

        How do high-end home LEDs get around this? Do they have a battery that caches the current between cycles?

        When my wife and I bought our place, we renovated and made all lights LED. The overheads in the living room and kitchen are quite bright and steady, so they must avoid this somehow.

        • @[email protected]
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          611 months ago

          A bridge rectifier flips the negative current to positive, so instead of a sine wave you get a series of humps. Then a capacitor acts as a battery like you describe to smooth out the dip between humps.

          • @[email protected]
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            311 months ago

            There are half wave rectifiers and full wave rectifiers. The former only converts the positive AC to DC and shuts off for the negative half (causing flickering). The latter will convert both positive and negative halves to DC and don’t flicker.

            • @[email protected]
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              111 months ago

              Well, LED lights are half-wave rectifiers that light up, so you wouldn’t add one. I don’t think I’ve ever heard of a half wave rectifier referred to as a bridge rectifier.