LED shop light shimmer

[soob]

I recently replaced the T8 bulbs in my garage with "Hyperikon" T8 LED tubes. The hyperikons are very bright, efficient, and have a high CRI (90+). They have countless positive reviews on Amazon. My initial impression was very positive as well.

But--

After I put them in, I started noticing intermittent flickering. I figured it must be voltage drop on the line and had been thinking about running a new circuit for the lights.

But something didn't seem right. When I looked at the bulbs I'd never see flicker. It always seemed to happen at the edge of my vision like a hallucination or a nightmare. Anyway I did some research online and discovered that LEDs sometimes "shimmer" as a result of the driver not smoothing out the alternating current (forgive me if I'm not articulating this right...).

So I got an app for my phone (Android -- "LED flicker finder"), which measures the brightness 100x per second and tells you how much varies. I tried it on the LED floods in my home office. They were steady as a rock: 1-2% variation. The LED bulb in my lamp? The same. The fluorescent in my kitchen? The same.

But in the garage with the Hyperikon T8 LEDs, the variation in light output was 10%. Yikes. I don't know if this is an issue with cheap parts or a sacrifice to get really high lumens per watt or what, but it's a real issue for me.

Anybody else notice or aware of this issue? Is this an issue with all T8 LED replacements or just the hyperikon ones?

 

[ard]

I have noticed this with some LED lights

I haven't noticed this on the 32 hyperikon tubes I've installed.
2200 lumen, 4500K color, frosted covers

You should call Hyperikon- see what that say.

(FWIW- the flicker can be worse that what that app is measuring- the 'frame rate' of the phone will limit the measurement...)

 

[apollo11]

I recently replaced the T8 bulbs in my garage with "Hyperikon" T8 LED tubes. The hyperikons are very bright, efficient, and have a high CRI (90+). They have countless positive reviews on Amazon. My initial impression was very positive as well.

But--

After I put them in, I started noticing intermittent flickering. I figured it must be voltage drop on the line and had been thinking about running a new circuit for the lights.

But something didn't seem right. When I looked at the bulbs I'd never see flicker. It always seemed to happen at the edge of my vision like a hallucination or a nightmare. Anyway I did some research online and discovered that LEDs sometimes "shimmer" as a result of the driver not smoothing out the alternating current (forgive me if I'm not articulating this right...).

So I got an app for my phone (Android -- "LED flicker finder"), which measures the brightness 100x per second and tells you how much varies. I tried it on the LED floods in my home office. They were steady as a rock: 1-2% variation. The LED bulb in my lamp? The same. The fluorescent in my kitchen? The same.

But in the garage with the Hyperikon T8 LEDs, the variation in light output was 10%. Yikes. I don't know if this is an issue with cheap parts or a sacrifice to get really high lumens per watt or what, but it's a real issue for me.

Anybody else notice or aware of this issue? Is this an issue with all T8 LED replacements or just the hyperikon ones?

 

[soob]

That's really what the sensation is like -- like something coming at you at the edge of your vision. It's unnerving.

ard: the app says the phone is sampling at 100x per second. I observed greater than 10% variation at regular intervals (like 1x per second or so). I think it was typically about 12%.

I tried it with some other Hyperikon led strip lights (made to fit the T5HO) and they did the same thing, just about the same degree of dimming. Those were on a different circuit and panel (though at the same residence...).

I guess whether you notice this shimmering might be subjective, but would you be able to check yours to see if you can measure the variation?

Thanks BTW.

 

[Platonic Solid]

Are these ballast bypass or ballast compatible bulbs? I've seen this with ballast compatible bulbs. Both my son and I could see the high frequency flicker - which is really annoying - yet no one else could see it.

 

[soob]

No ballast.

But I can't see the flicker -- not directly, anyway. I just intermittently sense a flicker at the edge of my vision. Like maybe every couple minutes. It's really annoying.

 

[kwschumm]

LED flicker seems to be a failure mode of LED lights. The LEDs themselves might last for tens of thousands of hours but the power electronics seem to be far less reliable. I've had a dozen or more LED lights fail in this way, usually as infant mortality. Once they get past the first month or two then they seem good for a long time.

 

[soob]

I e-mailed hyperikon and they said it was a "manufacturing error" and that they would replace the bulbs and that I should toss the old ones in the trash.

It looked like a form e-mail. So they're going to send me another... $750 worth of their bulbs? Without even like addressing my concerns? I mean, I don't think it's a manufacturing error. It's probably cheap components. I wonder if they'll actually do it. Should I even bother with this or just demand that they take them back and refund my money? The clock is ticking on a credit card dispute...

 

[ard]

How many hyperikon flicker posts have you found?

 

[Bert_]

I've seen some that are really bad, they were some led surface mount puck lights. The flicker was pretty noticeable if you moved your hand quickly. Most of the led christmas lights do it too. The problem with the above is that the led's are just ran on rectified line voltage, no filter or high frequency driver.

I would let them replace the lamps, no reason not to. If the replacements have the same problem then I'd be making some phone calls...

 

[soob]

How many hyperikon flicker posts have you found?

Not many. Like I said, it's not easy to detect, and maybe not everyone can see it. But I can and it's definitely there. There are a few people complaining about the hyperikons flickering due to voltage drops (this may be erroneous as to the cause) and one guy did a review where he put them under a light meter and noticed this:

On the general issue of LED shimmer there are lots of sources. E.g.:

http://www.ledjournal.com/main/blogs/flicker-shimmer-and-ripple-lessons-in-light-quality/

There's enough interest in this that people have written software programs to find flickering bulbs (though they do seem to be intended for finding individual defective bulbs rather than evaluating all of them). Plus there's the fact that I checked a dozen other bulbs and none of them had this kind of oscillating brightness issue. But all three of the different models of hyperikon tubes I tested do it. All pretty much the same, too, about 12% variation in brightness.

 

[soob]

Oh, I guess I should point out that unlike 99% of people reviewing these bulbs, I have a *lot* of them -- 40 IIRC installed in my garage. That's a lot of light and so a 10% variation amounts to like 8000 lumens.

 

[Bluevista]

Flicker is a major problem, the lighting elephant in the corner of the room of sorts.
I have to keep up on this stuff because my daughter has epilepsy and the LED flickering can induce seizures, there is also the possibility of them causing permanent eye damage over long term exposure. It reminds me of the debacle the fluoroscope X-Ray fitting machines at shoes stores caused.
I was going to get LED's for my garage but after researching the seizure angle and learning of all the other unresolved problems I went with T8 fluorescents with mirror reflectors. I can easily convert to T8 LED's if they get all the bugs worked out but the reflectors won't do much since the light all goes down.
I go by the Cheap-Fast-Good rule, and cheap and fast is never good.

 

[cybrdyke]

Words like flicker and shimmer aren't very helpful in describing what Soob & BlueVista are experiencing, but unfortunately, there aren't really any other words. It's not a strobe light effect, or a candle flicker. It's also not just an LED issue. Optical flicker at lower frequencies can be seen by some people. At higher frequencies it cant be seen, but there are still ramifications. People who are autistic, or even near autistic, and people who are epileptic are sensitive to "optical flicker". Other folks can experience eye strain, headaches, etc...

There are so many really cheap products on the internet and it's tempting to buy them. This is a good example of the difference between junk and quality, even though you may be one of the people who will never notice it. There's a reason that companies like Hyperikon, Feit, etc., are selling on Amazon and not thru professional channels.

My guess is that the tubes that Soob gets in replacement of the "defectives" will have the same issue. I hope for his sake that I'm wrong. But they use a junk driver on crappy diodes and this is the result.

CD

 

[PoorOwner]

I have so far a row of Feit and have not noticed such effect, I also turn on a couple other Feit in the other areas, when they are all on I don't notice any output differences or stroking. I also replaced all the PAR38 with feit LED, they look very normal to me.

The Hyperkion bypass tubes I have also used before, but only 2-4 tubes at a time, I recall mine don't have diffuser / frosted so they were harsh, but it was through a light diffuser panel. It was always a bit of glare and not seem as comfortable to be under.

I had very bad reliability with Feit when they made the CFLs though.

 

[ard]

1. If this is such a pervasive and massive problem with LEDs, there is virtually NO mention of this here. Or in LED reviews on line. Search for it, you will find bits and pieces, but it would seem to be a central spec we should apply universally. I AM NOT DOUBTING THE OP, NOR DOUBTING THIS OCCURS. I have seen it. Just surprised it isn't discussed broadly.

2. Hyperikon MUST be aware of this. I would not doubt at all if they know on a lot by lot basis how their bulbs behave. Indeed, they may take risks and ship out lots knowing full well there WILL be complants and returns. The canned, automatic, "toss them out, we will send new" is very telling. Furthermore I would not be surprised if the replacemnet bulbs come from their "A+ Stock".

If I was running OPs at Hyperikon, that's what I'd do....

PS One think I've seen with some LEDs (not the HYPs I have) is a 'strobe' of a specific color. Usually a blue- just a flash of a pure vivid color, then back to white....

 

[soob]

I'm surprised, too. I guess most people just don't notice. I had a couple hyperikon tubes that I was using for night lights, basically, and I never noticed this even though they're doing it, too. I did notice that the lights looked... weird, but I didn't think much of it because they're bare LEDs without a diffuser, and I don't have much experience looking directly at them.

Also, I'd note that Hyperikon T8s are NOT cheap, at least not compared to the T8 replacements you see in the big box stores. They cost more and -- at least, appear -- to be much better made. The big box store LED T8s require a ballast and are inside a glass tube. The Hyperikons have two part bodies, with the back being an aluminum heat sink and the front being clear plastic. They also have better (claimed) specs, like high CRI and better efficiency.

Also, Feit is a pretty well established company. It does sell in retail stores (like costco) and they make most of the store brand bulbs for Lowes (and probably others).

 

[Lelandwelds]

So, every lamp pulses in time with each other? Due to sine wave on the power line maybe? Why not drop a linear device in the driver somewhere? ( almost no ripple, nearly as efficient) Why not add random different circuits to have pulse out of phase and self cancel on average? How about plain old capacitors?

This can't be hard or expensive to fix.

 

[cybrdyke]

1. If this is such a pervasive and massive problem with LEDs, there is virtually NO mention of this here. .

It's not pervasive. But it happens.
CD

 

[thammel]

I need to follow this thread! I bought 4 of the t8 tubes (5000K) from hyperikon and have not noticed any effect yet.....but I need a total of 32, and as you say , at about $10 per tube, they are not cheap!

One question for you - are the ones you have where you notice the shimmer frosted or unfrosted? I wonder if frosted tubes would lessen the effect?

My tubes are frosted. I've been trying to get cheaper tubes from myledtubes, but they have been out of stock for months now.

Tom

 

[PoorOwner]

OP have you checked the voltage for fluctuation on your light circuit, there is a circuit in my house where traditional light bulb will go slightly dim occasionally, the LED lamps plugged into it also exhibit the same behavior. I think this is caused by the very old GFCI receptacle, (every thing is downstream of this receptacle)

 

[soob]

So, every lamp pulses in time with each other? Due to sine wave on the power line maybe?

Yeah, as far as I can tell that's exactly what they're doing.

Why not drop a linear device in the driver somewhere? ( almost no ripple, nearly as efficient)

'Cause I don't know what that means!

Why not add random different circuits to have pulse out of phase and self cancel on average?

I also don't know what that means.

How about plain old capacitors?

I know what those are -- kind of. But how are you suggesting I use 'em to fix this?

This can't be hard or expensive to fix.

As far as I can see, the tubes can't be easily disassembled. Each of them takes line voltage and has its own driver. Any solution that involves operating on 40 of them isn't going to be feasible for me. If it's something I can install in the circuit before the lights -- that I can probably do. But I don't know what that'd be.

I'd appreciate any help you might be able to offer, though!

OP have you checked the voltage for fluctuation on your light circuit, there is a circuit in my house where traditional light bulb will go slightly dim occasionally, the LED lamps plugged into it also exhibit the same behavior. I think this is caused by the very old GFCI receptacle, (every thing is downstream of this receptacle)

That's what I was originally thinking, but it seems steady to me.

I need to follow this thread! I bought 4 of the t8 tubes (5000K) from hyperikon and have not noticed any effect yet.....but I need a total of 32, and as you say , at about $10 per tube, they are not cheap!

One question for you - are the ones you have where you notice the shimmer frosted or unfrosted? I wonder if frosted tubes would lessen the effect?

Unfrosted. The extra diffusion might lessen the perceptibility, but I don't know.

I did get some frosted cheapo T8 replacement tubes to test out. They're Lowes brand (and single end power; rewiring all my fixtures would be fun...). They have a bit more flicker than my other LEDs, but it's only about 3%, much better than the hyperikons. I don't think it'd be an issue.

 

[soob]

Ohhh. The different legs alternate at opposite times. So you're saying I should wire up half the lights on one leg and half the lights on the other leg so they shimmer and dim exactly out of sync with each other.

That sounds like a PITA to wire, but it'd probably work, eh? Would just need a hot from a circuit on the other leg and a relay or two.

 

[ForceFed70]

I like the thinking, but hooking 1/2 the lamps to a different leg won't help. The 1st thing that happens in the power supply is to rectify the voltage. Once rectified, it doesn't matter which leg you're using, the waveform is identical in shape and timing.

As others have mentioned. This is common with cheap LED fixtures. It's a result of using a low quality power supply.

 

[soob]

Oh. Well thanks for reminding me why it was a good call to drop physics II. Well, I mean, maybe not -- but a good call for me at least.

I was about to try rigging one up, too.

Any other ideas -- or just scrap the bulbs? Supposedly Hyperikon is very good about returns. They even seem to claim that they'll buy the bulbs back from you if you bought them elsewhere.

 

[ForceFed70]

Oh. Well thanks for reminding me why it was a good call to drop physics II. Well, I mean, maybe not -- but a good call for me at least.

I was about to try rigging one up, too.

Any other ideas -- or just scrap the bulbs? Supposedly Hyperikon is very good about returns. They even seem to claim that they'll buy the bulbs back from you if you bought them elsewhere.

You're welcome. Although I don't think a physics class would have been enough for you to clue in on this one. Took me some thinking and I spent 3 years in college taking an Electrical Engineering Technology program (Essentially 1/2 way to becoming and electrical engineer). Tho I'll also admit - I'm more than a little rusty these days.

 

[Jozw30]

The non-visible flicker is due to driver designs with no input filtering (typically electrolytic capacitors). The E-caps are also the weak link in the driver life expectancy.

E-star and Title24 (California) are starting to address this in their standards so it is getting better.

It’s taking a while for the end users to get educated enough to get good quality light from LEDs.

If possible, ask the place you are purchasing from what the flicker percent is. Look for 30% or less. If they can’t answer assume it’s 100%.

You can “usually” see it without an app by simply turning on the video camera on your cell phone. You’ll see vertical dark bands across the screen.

Don’t see much on here about folks talking about CRI either. You get what you pay for. Anything under 80CRI and your colors will be all muted. I won’t use anything under 90CRI. It’s getting pretty standard now, again because E-star and T24 are gradually pushing higher specs. But it’s still a premium....

You will always be able to buy cheaper products that look like they perform but there’s much more to quality lighting than lumens and footcandles......

 

[soob]

There don't seem to be a lot of options for 90+ CRI T8 leds, at least not in a resaonable price range. Or am I wrong about that?

 

[cybrdyke]

There don't seem to be a lot of options for 90+ CRI T8 leds, at least not in a resaonable price range. Or am I wrong about that?

You're not wrong, but there are a few. Considering that we've been living with 70 CRI for decades and 80 CRI for the last 7 or 8 years, it's not crucial to use 90 CRI. The quality of light from 90 CRI is impressive, and in a few years it will be pretty normal, but 80 is sufficient for most spaces.
CD

 

[Jozw30]

I guess I’m a “lighting snob” (it’s what I do for a living), I spend so much time staring at LED’s I try to only use the best stuff where my eyes are concerned.

I’m like a lot of you and getting older so i’m looking for every chance to reduce fatigue and eye strain.

I don’t work with the fluorescent tube retrofits so I’m not really up on what’s available in CRI. If you can work with 70CRI, go for it. You’ll get more lumens from the same model luminaire usually.

Just broke ground on my new shop and I’ll save money somewhere other than the lighting.

Didn’t mean to cause trouble just lots of bad product out there and many end users get caught by pricing and lumen numbers don’t even know what they don’t know about lighting.

 

[soob]

Well, yeah. And thanks for your input by the way, cybrdyke and Joz. I really do appreciate it.

I have been using 85 and 90+ CRI flourescents for a few years and I'm spoiled. I also will end up with about 120+ tubes so the cost is, ultimately, consequential. The only other 90+ CRI tubes I see for sale aren't just more expensive, they're less efficient too. Sucking down more juice drives up my cooling bills. Putting out less light limits the benefit of high CRI anyway.

I ended up buying a bunch of 80 CRI T8 LED tubes at Lowes for ~$3.50 each. I figure that's going to tide me over until the technology matures.

They do shimmer somewhat but the light meter only measures 3-5% oscillation (instead of 10-12% like on the hyperikons). I don't think this is the actual shimmer effect, just what the phone sees. I do occasionally notice a peripheral flicker (at least, I think I have), but it's tolerable.

I am going to return the hyperikon bulbs monday. They sent me a prepaid return label so I figure that's going to go over as well as it could.

The guy I was talking to there said an engineer would talk to me about the bulbs but he never did get back to me.

 

[cybrdyke]

The only other 90+ CRI tubes I see for sale aren't just more expensive, they're less efficient too. .

At this stage in LED technology, this is the case with most lamp styles.
CD

 

[Platonic Solid]

Less efficient in term of "lumens per watt", but no one has done a proper comparison study between perceived contrast of "X" illuminance @ "Y" CRI (or new TM-30-15) = <"X" illuminance @ >"Y" CRI. What's missing is a "color correct contrast per watt" scale.

 

[Jozw30]

Problem is these standards are just being developed and are evolving. CRI for instance isn’t even really good for LED’s, it was developed for fluorescent/HID lighting. There is a new std being adopted (although slowly) called CQS.

The CRI (Ra) number for LED lights doesn’t tell the whole color rendering story. Part of the problem is that even the best the down converted blue die doesn’t produce the full spectrum in the visible range that your eyes and brain are accustomed to (sunlight/incandescent).

It also has a blue spike/peak which doesn’t help. Blue is bad.....

All of this, plus the ripple current (non-visible flicker) from poorly designed electronics can mess with our heads, cause fatigue and eye strain.

For me personally, I just try to create the best visual comfort I can when I can. For a workshop shop, footcandles at your work height is critical, but I for sure do not want twenty overhead lights assaulting me with 100% flicker.

I do understand cost is a factor. If I had a choice between 80CRI with no non-visible flicker or 90CRI and flicker, I go with the 80CRI.

 

[yeldogt]

I wonder if this is why I don't typically like being around LED industrial type lights ... I don't have a problem with FL .. although some the HO T5 are very annoying. I thought maybe it was the cold color that most have +5000k.

I'm fine around the warm white typical non dimming replacement LED bulbs -- but they don't put out much light .. typically 60w to 100w equivalent.