LED slow off

Oct 18, 2019 9 Replies

Is it normal for LEDs to not turn offimmediately?


- = - Vasos Panagiotopoulos, Columbia'81+, Reagan, Mozart, Pindus blog: panix.com/~vjp2/ruminatn.htm - = - web: panix.com/~vjp2/vasos.htm facebook.com/vasjpan2 - linkedin.com/in/vasjpan02 - biostrategist.com ---{Nothing herein constitutes advice. Everything fully disclaimed.}---


do you mean an actual LED, e.g.

in which case no.

Or a mains lamp that uses LED, e.g.

in which case, it's quite normal for many types to "fade" away as the internal power supply runs down after it's switched off.

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** Correct.

And just to rub the point in, the yellow phosphor that turns the blue LED light into white has no persistence - unlike the phosphors use in fluoro tubes and scope CRTs or TV picture tubes.

.... Phil

Thanks. I though it was wierd. New bulb. It has like a circle of little dots of light which take a bit to shut down. In my mind LEDs should be the fastest to shut down. I am deathly afraid of halogen because of fires and I keep wondering if I got halogen instead.

- = - Vasos Panagiotopoulos, Columbia'81+, Reagan, Mozart, Pindus blog: panix.com/~vjp2/ruminatn.htm - = - web: panix.com/~vjp2/vasos.htm facebook.com/vasjpan2 - linkedin.com/in/vasjpan02 - biostrategist.com ---{Nothing herein constitutes advice. Everything fully disclaimed.}---

Most of the LED bulbs ( the 40, 60,100 watt replacements) are made up of a ring of LEDs that are about 1/8 to 1/4 of an inch square. The long

4 foot tubes are made up of a string of similar small LEDs. They usually have capacitors in them that hold a charge that takes a second or two to fully discharge.

What gets me is the LED tubes that I have. Some come on as soon as the switch is turned on and some take about 2 seconds to come on.

LED & hlogen look very different, there's no mistaking them.

NT

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** Well, that is a new phobia to me.

Wot is the fire issue with halogen light bulbs?

None the industry knows of.

..... Phil

It's the "ceiling heater" lamps that have/had the issue. The floor lamps with 200 or 300w bulbs in upward-facing dish reflectors. The fire hazard was from curtains getting blown on top of the lamps & catching fire.

I thought this was fairly well known.

NT

Mine do that too. The delay is perceptible and different from the tube fluorescent in the same room.

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