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What Happened to the 100000 Hour LED Bulbs?

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Re: What Happened to the 100000 Hour LED Bulbs?

#471

Post by lmilcin »

TheSpiceIsLife wrote: post #378
mrb wrote: post #235

Lifetime isn't even my #1 concern with LED bulbs. It's strobing/flickering. I film all the LED bulbs I buy in slow motion at 240 fps with an Android phone, and play the movie back on a PC with mplayer using the dot(".") key to move frame by frame. Here is a shot I made comparing 2 brands of LED bulbs: https://youtu.be/QbenId_F2RQ (Edit: yeah you don't have to transfer to a PC, just playing back in slow motion on the…

LED flicker could prove harmful or fatal if you work with anything that rotates or reciprocates. The rotating / reciprocating mass may appear stationary at some RPM. Just a reminder to only ever use incandescent or halogen lights around machinery you can touch while in operation: drills, lathes, mills, slotting machines, etc.

Oh, WOW!, I never thought of that! Thank you for this information. I thought I am very careful but it never occured to me this could be a problem.

Re: What Happened to the 100000 Hour LED Bulbs?

#472

Post by lmilcin »

handzbagz wrote: post #383
TheSpiceIsLife wrote: post #378

Earlier quoted context omitted.

LED flicker could prove harmful or fatal if you work with anything that rotates or reciprocates. The rotating / reciprocating mass may appear stationary at some RPM. Just a reminder to only ever use incandescent or halogen lights around machinery you can touch while in operation: drills, lathes, mills, slotting machines, etc.

Just how likely is this to happen though, it would have to be the only light source and be flickering with exactly the same frequency as the machinery is traveling at (which i assume for most devices varies a lot). Not saying it can't happen but it does seem stupidly hard to achieve.

Multiple light source of the same general characteristic (don't even have to be the same type of bulb) may produce this result.

The rotation frequency would have to be close to a relatively simple multiple (or fraction) of AC frequency but the way electric motors are contstructed if the piece is directly connected to a motor it is very likely it is true.

Re: What Happened to the 100000 Hour LED Bulbs?

#473

Post by pistachiopro »

yeutterg wrote: post #428
arm wrote: post #385

Earlier quoted context omitted.

In the huge HN thread here¹, yeutterg mentioned² their Bedtime Bulb: > “ I am on a mission to make lighting healthy. That's why I made Bedtime Bulb: https://bedtimebulb.com/ It has the lowest flicker I've ever seen in a bulb form factor—even less than those claiming to be "flicker-free." ” In addition to that, a few other database sites that test for flicker were mentioned here³. ―――――― ¹ — https://news.ycombinator.c…

I've tested a bunch of bulbs for flicker with a handheld flicker meter and with a photodiode connected to an oscilloscope. It's funny that some of the bulbs out there claiming to be "healthy" have terrible flicker. One product from Soraa was flickering at over 50%, almost as bad as the cheapest/worst LED bulbs you can buy. I don't have a database, but I can say that most (but not all) filament designs are terrible fo…

Thanks to GP for the links, I completely missed that previous thread!

And, yeah, I tried that Soraa healthy bulb, and it was shockingly bad, given how it was advertised. Even the regular Soraa bulbs were disappointingly flickery, though less so. Also, just looking at the pattern it makes on my phone's rolling shutter, the wave is quite saw-toothed, and I wonder if that makes it worse? I have some Ikea candelabra bulbs which were always pleasant, and I was surprised to see they also left quite a visible flicker pattern on my phone, though much more sinusoidal/smoother.

It's a shame about the flicker in the Soraa bulbs, since the colors really did seem nice.

Re: What Happened to the 100000 Hour LED Bulbs?

#475

Post by BuildTheRobots »

mrb wrote: post #235

Lifetime isn't even my #1 concern with LED bulbs. It's strobing/flickering. I film all the LED bulbs I buy in slow motion at 240 fps with an Android phone, and play the movie back on a PC with mplayer using the dot(".") key to move frame by frame. Here is a shot I made comparing 2 brands of LED bulbs: https://youtu.be/QbenId_F2RQ (Edit: yeah you don't have to transfer to a PC, just playing back in slow motion on the…

I'm surprised no one has mentioned hte rise of flickering LEDs on cars - though I think in this case it's caused by PWM dimming.

I mean, it looks absolutely fine as long as the light source and viewer are both static - just a shame vehicles tend to be moving :(

Re: What Happened to the 100000 Hour LED Bulbs?

#477

Post by consp »

mrb wrote: post #235

Lifetime isn't even my #1 concern with LED bulbs. It's strobing/flickering. I film all the LED bulbs I buy in slow motion at 240 fps with an Android phone, and play the movie back on a PC with mplayer using the dot(".") key to move frame by frame. Here is a shot I made comparing 2 brands of LED bulbs: https://youtu.be/QbenId_F2RQ (Edit: yeah you don't have to transfer to a PC, just playing back in slow motion on the…

Cheap brands generally use some form of capacitive dropper scheme. These result in the 120/100Hz flickering but is cheap to produce as very little components are needed (X2 class capacitor, maybe some current limiting resistor(s) and a discharge resistor, bridge rectifier, or even skip the rectifier altogether). They are not to be used with a dimmer. Some info on them [1]

The switch-mode power supplies in proper lamps get the stuff done way better and there will be no noticeable flicker. Maybe in the order of several kHz in ripple which you cannot see.

Also; cheap off brands (looking at you china) sometimes have caps rated at 250V which is far from the peak mains rate of about 320V (in 220/230V countries).

[1] https://www.powerelectronictips.com/whats-stuff-capacitive-p...

Re: What Happened to the 100000 Hour LED Bulbs?

#478

Post by NeedMoreTea »

ouid wrote: post #440
NeedMoreTea wrote: post #423

Earlier quoted context omitted.

Pretty common, about as common as the wagon wheel effect in 24fps film movies. In just the same way, the item can appear to stop, run slow, or run backwards, just as with film. No it does not have to be the only light source, just the nearest one to the machinery. Fluorescent tubes are most noticeable, LEDs a little less. Tungsten or Halogen are the only sensible option for workpiece illumination.

I believe halogen is also tungsten.

It is. Just running at higher temperature. They tend to be marketed as something separate and distinct though.

Re: What Happened to the 100000 Hour LED Bulbs?

#479

Post by TheSpiceIsLife »

TheSpiceIsLife wrote: post #378
mrb wrote: post #235

Lifetime isn't even my #1 concern with LED bulbs. It's strobing/flickering. I film all the LED bulbs I buy in slow motion at 240 fps with an Android phone, and play the movie back on a PC with mplayer using the dot(".") key to move frame by frame. Here is a shot I made comparing 2 brands of LED bulbs: https://youtu.be/QbenId_F2RQ (Edit: yeah you don't have to transfer to a PC, just playing back in slow motion on the…

LED flicker could prove harmful or fatal if you work with anything that rotates or reciprocates. The rotating / reciprocating mass may appear stationary at some RPM. Just a reminder to only ever use incandescent or halogen lights around machinery you can touch while in operation: drills, lathes, mills, slotting machines, etc.

So I went of and did a tiny bit of research. Turns out there are LED work lamps designed specifically for lathes etc.

So, evidently, I may have over stated my initial claim about only using incandescent lights.

Still, it’s something to me conscious of.

Re: What Happened to the 100000 Hour LED Bulbs?

#480

Post by NeedMoreTea »

mcv wrote: post #469
NeedMoreTea wrote: post #423

Earlier quoted context omitted.

Pretty common, about as common as the wagon wheel effect in 24fps film movies. In just the same way, the item can appear to stop, run slow, or run backwards, just as with film. No it does not have to be the only light source, just the nearest one to the machinery. Fluorescent tubes are most noticeable, LEDs a little less. Tungsten or Halogen are the only sensible option for workpiece illumination.

Or, of course, just use a LED that properly smooths out the DC. It's not hard to do, and a quality LED manufacturer should get this right. The only excuse for flickering is a cheap LED that cuts cost for circuitry.

Oh I agree, but a surprising number of LED bulbs have some degree of flicker, even from those makes you might expect to do better. A purpose made work lamp should get it right though. Hopefully. Maybe.

For my hobby stuff, I just bought a couple of spare halogens that should see me out.

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