Do you guys actually know how LED lighting works? Cree making misleading comments

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Electric-Light

Senior Member
There are many LED brands out there, but Cree on particular really makes some interesting misleading contentious comments. I know they're taking a jab at phosphor coated evacuated glass tube fluorescent lamps when they say "fluorescent" but its funny that they make all these comments since their business almost entirely depend on the same technology them stomp all over. :lol:

?Customers no longer have to accept outdated fluorescent technology as their only choice,? says Cree CEO Chuck Swoboda vie prepared statement, adding, ?There?s no reason to install another linear fluorescent tube again.?
http://www.bizjournals.com/triangle.../cree-says-your-office-will-never-need-a.html

?There [are] a lot of sacrifices we?ve been living with in this fluorescent world,? said Jeff Hungarter, product portfolio manager for Cree Lighting. ?There is a huge opportunity.?
http://www.greentechmedia.com/articles/read/Cree-Takes-on-4B-Fluorescent-Lighting-Market-With-LEDs

I made a diagram and smashed open an LED light bulb so you can see how they work and understand what solid state fluorescent lamp means.

This is how LED light bulbs work.
2L4lgLI.jpg



This is an actual demonstration of white light emitted from the fluorescent phosphor. I used an external blue LED to excite the phosphor on one of the chips inside the LED light bulb I cracked open.
4o2eB52.jpg



"Despite its
noble premise built from energy policy to
reduce consumption, fluorescent lighting
requires compromise in almost every way: from
flickering and inadequate dimming to mercury
use and poor-quality light." quoting Jeff Hungarter, product portfolio manager with
Cree Inc. as printed on page 32 in July 2014 www.EBMag.com

https://www.creelink.com/exLink.asp?19706952OV78E19I37602548

There's some truth to Jeff's comment and I strongly agree with some of his points. I find poor quality light such as strange distortion, visible chromaticity mismatch between lamps and flickering aggravating too.

High quality electronically ballasted fluorescent lamps using low pressure mercury discharge technology often have less flicker than incandescent lamps. The amount of flicker is dictated by the driver rather than the type of fluorescent lamp. Some lab tested flicker values for some bulbs covered in Lightfair 2012. You can read the full report here: http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/poplawski_dimming_lightfair2012.pdf

  • 60W A19 incandescent: 6.6% percent flicker and 0.02 flicker index.
  • 60W equivalent CFL #1: 5.1% percent flicker and 0.01 flicker index.
  • 60W equivalent CFL #2: 1.8% percent flicker and 0.00 flicker index.

I'm not particularly happy with the excess flicker in one of the solid state fluorescent bulbs meant to replace a 60W bulb. You are probably wondering :? probably because you're not familiar with how LED light bulbs work.
LED light bulbs are predominantly based on pcLED type LEDs which uses the fluorescent technology that some criticizes as outdated. Blue LED chips are smothered and buried in fluorescent phosphor or they're surrounded by walls impregnated with the same. The phosphor makes yellow light and mix with the blue light bleeding through it and makes a white light.

So, this LED solid state fluorescent bulb have flicker and inadequate dimming issues. The bulb is sold as a 60W equivalent and uses 8.5W and makes 800 lumens. I understand that this bulb is getting discontinued and replaced by a newer product that uses 11W to make about the same light. There's a noticeable distortion of moving objects and it especially gives me a headache when I'm using my camera, because it creates a pretty bad rolling shutter effect. Review site agrees with this bulb having a lot of flicker. The review on this LED bulb says the flicker Percent: 44%, Flicker Index: 0.13. I also noticed a visible color difference between the same type products from different batches too. One made in 7th week of 2013 and another in 36th week of 2014 have a visible color difference. I'm not impressed but I'm not disappointed, its a compromise I've come to expect from solid state fluorescent lamp pcLED technology.

Cree's Jeff commented on inadequate dimming with fluorescent lights. That certain pcLED SSFL did not dim anywhere near as well as a pair of F32T8 standard fluorescent lamps on a Lutron Hi-Lume dimming ballast. So he is partially right that some "fluorescent" lights have inadequate dimming, but it's a driver issue.
 
Last edited:

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
There are many LED brands out there, but Cree on particular really makes some interesting misleading contentious comments. I know they're taking a jab at phosphor coated evacuated glass tube fluorescent lamps when they say "fluorescent" but its funny that they make all these comments since their business almost entirely depend on the same technology them stomp all over. :lol:

?Customers no longer have to accept outdated fluorescent technology as their only choice,? says Cree CEO Chuck Swoboda vie prepared statement, adding, ?There?s no reason to install another linear fluorescent tube again.?
http://www.bizjournals.com/triangle.../cree-says-your-office-will-never-need-a.html

?There [are] a lot of sacrifices we?ve been living with in this fluorescent world,? said Jeff Hungarter, product portfolio manager for Cree Lighting. ?There is a huge opportunity.?
http://www.greentechmedia.com/articles/read/Cree-Takes-on-4B-Fluorescent-Lighting-Market-With-LEDs

I made a diagram and smashed open an LED light bulb so you can see how they work and understand what solid state fluorescent lamp means.

This is how LED light bulbs work.
2L4lgLI.jpg



This is an actual demonstration of white light emitted from the fluorescent phosphor. I used an external blue LED to excite the phosphor on one of the chips inside the LED light bulb I cracked open.
4o2eB52.jpg



"Despite its
noble premise built from energy policy to
reduce consumption, fluorescent lighting
requires compromise in almost every way: from
flickering and inadequate dimming to mercury
use and poor-quality light." quoting Jeff Hungarter, product portfolio manager with
Cree Inc. as printed on page 32 in July 2014 www.EBMag.com

https://www.creelink.com/exLink.asp?19706952OV78E19I37602548

There's some truth to Jeff's comment and I strongly agree with some of his points. I find poor quality light such as strange distortion, visible chromaticity mismatch between lamps and flickering aggravating too.

High quality electronically ballasted fluorescent lamps using low pressure mercury discharge technology often have less flicker than incandescent lamps. The amount of flicker is dictated by the driver rather than the type of fluorescent lamp. Some lab tested flicker values for some bulbs covered in Lightfair 2012. You can read the full report here: http://apps1.eere.energy.gov/buildings/publications/pdfs/ssl/poplawski_dimming_lightfair2012.pdf

  • 60W A19 incandescent: 6.6% percent flicker and 0.02 flicker index.
  • 60W equivalent CFL #1: 5.1% percent flicker and 0.01 flicker index.
  • 60W equivalent CFL #2: 1.8% percent flicker and 0.00 flicker index.

I'm not particularly happy with the excess flicker in one of the solid state fluorescent bulbs meant to replace a 60W bulb. You are probably wondering :? probably because you're not familiar with how LED light bulbs work.
LED light bulbs are predominantly based on pcLED type LEDs which uses the fluorescent technology that some criticizes as outdated. Blue LED chips are smothered and buried in fluorescent phosphor or they're surrounded by walls impregnated with the same. The phosphor makes yellow light and mix with the blue light bleeding through it and makes a white light.

So, this LED solid state fluorescent bulb have flicker and inadequate dimming issues. The bulb is sold as a 60W equivalent and uses 8.5W and makes 800 lumens. I understand that this bulb is getting discontinued and replaced by a newer product that uses 11W to make about the same light. There's a noticeable distortion of moving objects and it especially gives me a headache when I'm using my camera, because it creates a pretty bad rolling shutter effect. Review site agrees with this bulb having a lot of flicker. The review on this LED bulb says the flicker Percent: 44%, Flicker Index: 0.13. I also noticed a visible color difference between the same type products from different batches too. One made in 7th week of 2013 and another in 36th week of 2014 have a visible color difference. I'm not impressed but I'm not disappointed, its a compromise I've come to expect from solid state fluorescent lamp pcLED technology.

Cree's Jeff commented on inadequate dimming with fluorescent lights. That certain pcLED SSFL did not dim anywhere near as well as a pair of F32T8 standard fluorescent lamps on a Lutron Hi-Lume dimming ballast. So he is partially right that some "fluorescent" lights have inadequate dimming, but it's a driver issue.


Good information but it almost sounds like you work for a competitor to Cree Lighting.
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
A better question might be do we care how it works?:D

I do. I realize that E-L exhibits a bit of a vendetta against LEDs, but his research and easily understandable reports are very interesting to read.

I really like LEDs for close up lighting, like in head lamps, and for flashlights. LEDs are hands down winners there.

LEDs, to me, are just one of many forms of light production we have at our disposal. I like CFLs for some applications, incandescent for others, and so on.

I would rather hear about how a device works than boasting coming from it's maker, any day.

As a photographer, I am pretty familiar with light and color. Nonetheless, I use the specs as estimation and rate the light by how I like it in the manner that I use it. If I like it, I buy more. If not, I try something else.

Today I am thinking about buying an LED 'bulb' for my trouble light. I dropped the first residential LED 'bulb' I ever saw off a ladder onto a hardwood floor. It bounced. When I put it back in I was very impressed at how close the color was to an incandescent. Also, it ran at a low temp, very useful when the metal reflector of the trouble light touches sensitive skin.

That will be my first 'residential' LED.

I thought the OP was done very well. The poster deserves thanks for that.
 

iwire

Moderator
Staff member
Location
Massachusetts
I do. I realize that E-L exhibits a bit of a vendetta against LEDs, but his research and easily understandable reports are very interesting to read.

His extreme bias takes away the credibility for me.


I would rather hear about how a device works than boasting coming from it's maker, any day.

I would as well, as long as the source is unbiased which clearly EL is not.

I do have respect for his honesty of his bias, that I find commendable. He is not here pretending to be neutral while feeding us cherry picked tidbits at the same time ignoring the same types of things florescent manufactures have done. (Think CFLs)

As a moderator I find his posts great, he keeps things active and provides a great many links. However on a personal level I find him to be a lot like Billy Mayes.
 

LEO2854

Esteemed Member
Location
Ma
I do. I realize that E-L exhibits a bit of a vendetta against LEDs, but his research and easily understandable reports are very interesting to read.

I really like LEDs for close up lighting, like in head lamps, and for flashlights. LEDs are hands down winners there.

LEDs, to me, are just one of many forms of light production we have at our disposal. I like CFLs for some applications, incandescent for others, and so on.

I would rather hear about how a device works than boasting coming from it's maker, any day.

As a photographer, I am pretty familiar with light and color. Nonetheless, I use the specs as estimation and rate the light by how I like it in the manner that I use it. If I like it, I buy more. If not, I try something else.

Today I am thinking about buying an LED 'bulb' for my trouble light. I dropped the first residential LED 'bulb' I ever saw off a ladder onto a hardwood floor. It bounced. When I put it back in I was very impressed at how close the color was to an incandescent. Also, it ran at a low temp, very useful when the metal reflector of the trouble light touches sensitive skin.

That will be my first 'residential' LED.

I thought the OP was done very well. The poster deserves thanks for that.


K8MHZ:

If you want a good trouble light Milwaukee makes an M-18 LED that's the best I've found thus far.. :thumbsup:
 

K8MHZ

Senior Member
Location
Michigan. It's a beautiful peninsula, I've looked
Occupation
Electrician
K8MHZ:

If you want a good trouble light Milwaukee makes an M-18 LED that's the best I've found thus far.. :thumbsup:

Thanks, but I was thinking about spending 9 bucks for a bulb to use in an existing trouble light. I have become so used to using a head lamp that I seldom use anything else. Yesterday I needed a trouble or portable light and went through four I found in my garage that all had burned out bulbs or lamps in them. So I decided the cheapest rectification and the most rugged would be using an LED in one of the trouble lights I already have.
 

big john

Senior Member
Location
Portland, ME
Clear to me - And I'm not being facetious

Truth, Justice...
I said in another thread, that in my opinion the only thing that remains to be seen is whether LED fixtures have anywhere near the advertised life expectancy. In the short term it is self-evident that they are an effective lighting source in many residential, commercial, and industrial applications.

So when I see someone making lengthy posts to justify the position that LEDs are only suitable as "decorations" that seems far removed from the truth.
 
So when I see someone making lengthy posts to justify the position that LEDs are only suitable as "decorations" that seems far removed from the truth.

Agreed. I've worked with LED fixtures and some rather complex lighting controllers. I've looked at the fixture construction and some of the physics. E-L's posts usually reek of "bad science" to me. That said, there are often some interesting and useful facts to tease out of them, but you have to find them first.
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
... LEDs are only suitable as "decorations" that seems far removed from the truth.

.... E-L's posts usually reek of "bad science" to me. ....

I don't have a dog in the hunt as to if EL is right or not. I rarely ever look at the quantum level physics for devices - I really don't care. I'm much more interested in the specifications. A mfg that lies, rarely ever gets a second chance with me. Having been involved in a few industrial LED applications, specifically aimed at reducing maintenance, the MFGs are outright lying about LED MTBF.

All this aside, the question concerned EL's "agenda". My comment stands - we are getting his opinion of Truth and Justice concerning LEDs. Calling it "far removed from the truth" and "reek of "bad science" appears to be stabbing him in the back for rendering a fairly informed opinion.

Be that as it may, if you have a differing, informed opinion, I'm interested in that as well.

there are often some interesting and useful facts to tease out of them, but you have to find them first
Yes, as is true of most all on here.

ice
 

iwire

Moderator
Staff member
Location
Massachusetts
Having been involved in a few industrial LED applications, specifically aimed at reducing maintenance, the MFGs are outright lying about LED MTBF.

I have no doubt of that and have never said otherwise.


That said what lighting manufacturer does not lie about the quality, durability or longevity of their products? :?
 

big john

Senior Member
Location
Portland, ME
...Appears to be stabbing him in the back for rendering a fairly informed opinion....
Not in the slightest: I think he's focusing exclusively on the negatives, and that is the opposite of a fair opinion.

Anyone can present a one-sided argument on any product in order to color people's judgement of that product.

Were I to see him put the same posting-effort into acknowledging efficiency improvements and end-user satisfaction then I'd be a lot more inclined to trust his perspective.
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
Not in the slightest: I think he's focusing exclusively on the negatives, and that is the opposite of a fair opinion. ...
I didn't say "fair opinion". I said "fairly informed opinion". I'm not particularly agreeing with him. However, I'm not seeing a fairly informed opinion from anyone else in this thread.

*(edit to delete me focusing on negatives)

ice
 
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iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
...Having been involved in a few industrial LED applications, specifically aimed at reducing maintenance, the MFGs are outright lying about LED MTBF. ...

I have no doubt of that and have never said otherwise. ...

Since you quoted me, I feel an obligation to respond - I'm having a hard time phrasing. How about:

Okay - Good we know that.

ice
 

iceworm

Curmudgeon still using printed IEEE Color Books
Location
North of the 65 parallel
Occupation
EE (Field - as little design as possible)
... That said what lighting manufacturer does not lie about the quality, durability or longevity of their products? :?

I will venture a medium informed opinion:
Most of the medium to high end HID industrial lighting is fairly close to the published specs. The technology is well understood and well known. If the mfgs get too far out it is readily apparent.

ice
 
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