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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?

#501

Post by moftz »

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 bought some LED string lights for my bedroom because they were cheap. They turned out to be incredibly annoying due to the 60Hz flickering. Staring at them, it wasn't noticeable but the moment you moved your head or moved something quickly you could see the strobe effect. I trashed them and bought some incandescent lights.

Re: What Happened to the 100000 Hour LED Bulbs?

#502

Post by yeutterg »

retSava wrote: post #495
yeutterg wrote: post #428

Earlier quoted context omitted.

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…

> flickering at over 50% what does that mean? Duty cycle is 50%, frequency at something Hz? Not being snarky - curious whether there is some kind of standard that your tool compares against. A duty cycle 50% (or any percent really) isn't bad in itself, it's the frequency that is the culprit. Too low PWM freq and you'll notice it.

When I refer to % flicker, I am talking about the modulation % as defined by IEEE 1789-2015 and some documentation from the Illuminating Engineering Society [0][1]. More correctly, invisible flashing is known as the stroboscopic effect or phantom array effect.

Two factors are often used to describe flicker for lighting:

- Modulation %, a.k.a. % Flicker [The height or modulation of the waveform, formula is 100% * (A - B) / (A + B)]

- Frequency [self-explanatory]

Flicker Index is also used (refer to [1] page 7 for more info) but rarely.

Duty cycle is not considered relevant, as you mentioned.

Some tools designed to measure lighting, such as my UPRtek CV600 [2], spit out % flicker, frequency, and flicker index, in addition to a bunch of spectrophotometry metrics. It's also pretty easy to calculate the modulation % with an oscilloscope and photodiode, it's just Vp-p / Vmax.

IEEE 1789 [0][1] roughly says that the higher the flicker frequency, the more acceptable it is to have a high modulation %. If you look at the graphic on [1] page 18, you can see this relationship. The white area is considered unsafe, the yellow area is "low-risk", and the green area is "safe." I don't 100% agree with this personally, as most incandescent lighting, with around 6-11% flicker at 100-120 Hz, would fall into the unsafe or low-risk category. But the Soraa product is definitely in the unsafe category.

For reference, I plotted my product (Bedtime Bulb) against an incandescent A19, Lighting Science's Goodnight A19, and Soraa's Healthy A19 on an IEEE 1789 graphic [3] with a Python tool I'm developing, Beautiful Flicker [4]. You can see that this incandescent, measured around 10%, is on the border between unsafe and low-risk by this standard.

Hope this helps!

[0] IEEE 1789: A new standard for evaluating flickering LEDs?: https://www.dial.de/en/blog/article/ieee-1789-a-new-standard...

[1] Flicker: Understanding the New Recommended Practice (PDF) https://www.energy.gov/sites/prod/files/2015/05/f22/miller%2...

[2] UPRtek CV600 https://www.uprtek.com/en/product/SPECTRAL-COLOR-METER/CV600...

[3] IEEE 1789 Graphic Comparing 4 Light Sources https://github.com/yeutterg/beautiful-flicker/blob/master/ou...

[4] Beautiful Flicker https://github.com/yeutterg/beautiful-flicker

Re: What Happened to the 100000 Hour LED Bulbs?

#503

Post by pistachiopro »

yeutterg wrote: post #491
pistachiopro wrote: post #473

Earlier quoted context omitted.

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 bulb…

The Soraa bulb looked pretty sinusoidal on my scope when I tested it briefly. But it's a lot of flicker regardless. What's interesting is that the bulb seems to have a nice build quality (from the outside, I didn't open it) and is quite heavy. I suspect they are putting a BIG heatsink in there, as violet pump phosphors tend to degrade quickly. The other thing that irks me about this product is the "zero blue" messagi…

That's right, the Soraa Healthy was very green! So, even without the flicker, the fact that it makes everybody look like undead zombies would be reason enough to disqualify it as a bedroom night light.

Re: What Happened to the 100000 Hour LED Bulbs?

#504

Post by yeutterg »

pistachiopro wrote: post #503
yeutterg wrote: post #491

Earlier quoted context omitted.

The Soraa bulb looked pretty sinusoidal on my scope when I tested it briefly. But it's a lot of flicker regardless. What's interesting is that the bulb seems to have a nice build quality (from the outside, I didn't open it) and is quite heavy. I suspect they are putting a BIG heatsink in there, as violet pump phosphors tend to degrade quickly. The other thing that irks me about this product is the "zero blue" messagi…

That's right, the Soraa Healthy was very green! So, even without the flicker, the fact that it makes everybody look like undead zombies would be reason enough to disqualify it as a bedroom night light.

Haha, totally agree! If you are still in the market for a low-blue, low-flicker solution, may I humbly suggest a look at my product, Bedtime Bulb [0]? I know I basically bashed the Soraa product here, but not without technical justification.

[0] https://bedtimebulb.com/

Re: What Happened to the 100000 Hour LED Bulbs?

#505

Post by mixmastamyk »

mixmastamyk wrote: post #451
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…

Interesting, I used to be very bothered by computer CRT monitors set at 60hz refresh and bright backgrounds. I'd go into the Windows control panel (most often) and increase it as far as it would go at the given resolution. Through trial and error I found that 72hz was acceptable/ok and 90hz and above was great. Other folks generally didn't notice, but sometimes could if I showed them to look sideways etc. This must e…

Small correction, the CFL did have some flicker, just small enough I didn't notice on first look.

Re: What Happened to the 100000 Hour LED Bulbs?

#506

Post by jfengel »

xiconfjs wrote: post #490
sosuke wrote: post #274

Earlier quoted context omitted.

I'm really happy to see you post this. Everyone else I've brought it up too just says I'm crazy. I might be crazy but not about the damn flickering/strobe. Especially when my dog bounces around it looks like she is in a strobe light. I did a couple of videos of it just to "prove" it in some fashion. https://www.youtube.com/watch?v=DddB_0QrV_8

I use a salt shaker and pour salt onto a plate - if I can make out single falling grain of salt on the way to the plate, I know this light source is not healthy for humans.

Hang on, how does that work?

Re: What Happened to the 100000 Hour LED Bulbs?

#507

Post by antisthenes »

antisthenes wrote: post #156
phasetransition wrote: post #105

So, engineering lead of a (outdoor) led Luminaire manufacturer here. And our sales director used to work for one of the biggest Asian light bulb OEMs. Happy to answer specific technical questions out there that this article triggered.

How much does it cost to make a LED bulb that runs no hotter than 45C at all times?

Well, thanks for not answering my question in any capacity, I guess...

Re: What Happened to the 100000 Hour LED Bulbs?

#508

Post by DoctorOetker »

xxs wrote: post #373
jandrese wrote: post #219

Earlier quoted context omitted.

Are they worse than CF bulbs? Those seemed like they should have been a nightmare for RF.

Depends, some of them are run at around 22KHz... so it's quite appaling

I think jandrese is referring to the fact that even a DC current through a plasma generates loads of RF, for example fluorescent tubes emit THz radiation!

Re: What Happened to the 100000 Hour LED Bulbs?

#509

Post by thinkling »

patal wrote: post #486
dpwm wrote: post #336

Earlier quoted context omitted.

Not sure this always holds. The worst bulbs I've personally seen for flicker were dimmable ones. The non-dimmable variant from the same range had no noticable flicker. Price paid also seems to be no indicator of quality – I've had premium LED bulbs from major makes, bought from a reputable wholesaler, that have died after 6 months within days of each other. I've had cheap no-name imports that have lasted years and ha…

A lot of "dimmable" LEDs are actually shifting the flicker pattern to dim the light (shorter on phases). This is for LEDs where the user dims per remote control. OP was talking about the older "legacy" dimming, where you have a wall-mounted knob that reduces the current. Works well with incandescent bulbs. But only few LEDs support this. If they do, their internal power converter likely won't flicker, because of thei…

I've been trying to switch to all-LED in a home with lots of legacy dimmers and it's been painful. Even on circuits where I've replaced older dimmers with new Lutron CFL/LED dimmers, I get flicker.

In other places I don't have dimmers but have low-voltage (12V) cans. Lots of flicker issues there too, presumably due to the 120->12V transformer at the can.

And then I have a light fixture that's both dimmed and a custom 12V setup. I've given up on finding a working dimmer/LED bulb (MR16 GU5.3) there. Probably need new 12V transformers?

Re: What Happened to the 100000 Hour LED Bulbs?

#510

Post by e12e »

handzbagz wrote: post #384
ams6110 wrote: post #300

Earlier quoted context omitted.

I bought about 100 regular incandescents in various wattages at Lowes before they were banned. I wish I had bought a lot more. They were about $0.25 per bulb at the clearance sale prices. CFLs and LEDs are poor substitutes from a quality-of-light standpoint. Also AFAIK there is no hazardous waste in a burned-out incandescent. You can throw it away with a clear conscience.

But you're using huge amounts more energy, I think that would rest on my conscience a little more.

Not if you have electric (temperature controlled) heating.
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