LED Light Flicker
#11
I put a 3-bulb fixture in our bedroom, and used LED vintage bulbs, 5000k as we like bright light.  After it was on for about 30 minutes, it started flickering.  I checked all the connections in the switch and light.  Also took the fixture back to where we bought it, and they tested it for 24 hours.  No flicker (I don't know what kind of bulbs they used, I should point out).

The electricians that wired the housed came out to have a look.  2 guys, 2 hours, they were still scratching their heads.  This is what they finally came up with:  The fixture was at the end of the circuit, and had 3 six watt LED bulbs in it.  They figured there wasn't enough current running through the circuit to make it work properly.  So they put one 60 watt incandescent in the fixture.  Problem solved, no more flicker.  Now we have 2 bright white 5000k LED bulbs in the fixture, and one 2700k incandescent bulb (the wife does not like this solution, by the way).

The electricians said they were seeing lots of flickering problems with LEDs, where there would normally not be a problem.  Has anyone seen anything like this?  Are there other possible solutions?  I can't find any vintage incandescent bulbs that are 5000k, they all seem to be 2700k or less.
True power makes no noise - Albert Schweitzer.       It's obvious he was referring to hand tools
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#12
I have a problem with flickering on some led lights.  But I think it's the dimmers.

That circuit has some weirdness, I don't think the electrician fully understood how to do 3 way lights. So the flickering possibly has to do with the ground path. And the dimmers are digital and the way they are connected is a little weird too, I'm pretty sure there is a small current that is being sent to ground.
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#13
I have two fixtures with LED bulbs and they will flicker occasionally.  They are on a dimmer and the dimmer may be the cause of this.

LEDs, unlike incandescent bulbs, can only be dimmed to about 30% brightness. Incandescent bulbs (and tungsten bulbs) can be dimmed to 5% brightness.

What I have never learned from solid sources if dimming will lengthen or shorten the life of an LED.  

I had a "night light" with a 15 watt bulb, which I dimmed to about 3 or 4 watts of brightness.  I never turned the light on or off.  If finally died last year after 19 years of service.   So the old incandescent bulbs had a longer life expectancy on dimmed levels.  They also used less electricity.

No one with scientific creds has ever said that LEDs will use less electricity on "dim", only that they will put out less light.  

Also, some LEDs are not dimmable.  I don't know if that means they won't dim, if they will burn out quickly, or if they will flicker.
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#14
you can't really answer a question about life without knowing the design specs.  LEDs have a shorter lifespan the closer to their max forward voltage they are driven.  If you find a good data sheet there will be a graph showing that.  But if they aren't being driven to that high of a Vf, the difference flattens out.  And for the most part, they just get dimmer, so it's not obvious that they are wearing out.

There are a lot of complexities to energy usage, it really depends on how efficient the converter circuit is.  But you could measure the amp draw and voltage fairly easily.  Wouldn't use an HF voltmeter though. A single LED will use less energy at lower currents and voltages.
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#15
No dimmer on this circuit, so that isn't an issue.
True power makes no noise - Albert Schweitzer.       It's obvious he was referring to hand tools
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#16
I'm not sure how it makes sense that replacing one bulb with an incandescent make the flicker go away.  Do you have any other (different style) led bulbs to try?
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#17
Put the bulb you took out back in and put it in the same socket.  Exchange the incandescent with a different bulb.  Does it flicker?   If so, exchange two LED bubs with each other.  Does it still flicker?
I tried not believing.  That did not work, so now I just believe
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#18
Replace the light switch.   Roly
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#19
@EricU:  I agree, makes no sense to me either.  But it did work.  I have tried multiple LED bulbs.  When it has all LED bulbs in it, it flickers.  Take out an LED, add a 60 watt incandescent, it doesn't flicker.

@Cecil: Not sure I'm following you, Cecil. Replace the incandescent with another incandescent? Or a different LED?

@Roly: I had the same thought, but the electricians checked it and said it was fine. Might do it anyway, a regular light switch is cheap. Or do they make special ones for LEDs?

Thanks for all the suggestions.
True power makes no noise - Albert Schweitzer.       It's obvious he was referring to hand tools
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#20
(07-09-2018, 11:57 PM)BaileyNo5 Wrote: @EricU:  I agree, makes no sense to me either.  But it did work.  I have tried multiple LED bulbs.  When it has all LED bulbs in it, it flickers.  Take out an LED, add a 60 watt incandescent, it doesn't flicker.

@Cecil:  Not sure I'm following you, Cecil.  Replace the incandescent with another incandescent? Or a different LED?

@Roly:  I had the same thought, but the electricians checked it and said it was fine.  Might do it anyway, a regular light switch is cheap.  Or do they make special ones for LEDs?

Thanks for all the suggestions.

They do not make a special switch for leds .  I would go one step above the 50 cent switches.     Sometimes the grease on the contacts causes an issue with very low current devices.  Roly
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