LED Downlights: to LED or not to LED, that is the question.

The $113 was also for more than 24 http://bsuserver.com/zencart/index.php?main_page=product_info&cPath=0&products_id=180&zenid=a4826e716d0922a76a85df277052fab5, so it may not help - the best price for 1 that I have seen is $118 inc.

Paul

This is a little confusing as a larger beam angle will exponentially decrease lux at a height of 2.4m



CFL's and LED/Halogen should never be compared as they cannot come close to each other in a down light situation.

Beam angles in my opinion are a bit of a wrought as they are hard to be measured accurately and there is no standard to have lights tested against.



the 30% rule your applying is probably pretty close, but there is such a variance even in CREE models that it could be up to 50% less.

I still don't know why people are spending good money on companies without any independent testing, it costs me around $800-$1200 per model to have a NATA test done, why would you buy off a company who won't invest such a small amount in their company.

The only reason I'm getting Brighgreen is because of the various types of LEDs they offer, so that my entire house can match- not just the downlights in the ceiling. I'd be happy to look at any other company that offered as much variety...

Thanks for the link Paul. They're selling singles at the same price my suppllier has quoted them to me at! Think i'll have to go have a chat to them...

Brightgreen has a great product and has all the testing I mentioned so I wasn't really aiming that comment at them.

I saved you another $1.50
http://www.electricalproducts.com.au/brightgreen-d900-led-downlight.html

Hello.

I stand by Pierlite Starburst L.e.d downlights... You cannot beat the quality of these, we have never had any probs regarding installation or faulty units, they sell for 120.00 from middys.

I tend to shy away from china l.e.d's, however we do have an installation with 120+ l.e.d's, the owner is insisting on installing imported l.e.d downlights @ 60.00 each, Im skeptical but ill let you know how they turn out.

chris

My hubby is a fan of pierlight too

try holding a Starburst after 10mins or so, I put a hole in my couch with one.

Hi, I've been installing BrightGreen D900's and came across this topic. I actually have a problem with them though, maybe someone can help?

Although they are expensive I love the design, they look much better than halogens both on and off, I love the light quality in my house they appear brighter and cleaner than the halogens adjacent to them and I like the fact that they come with a dimmable driver, I like that they come with a plug, so you can legally install them if you have sockets in your roof, but....

I have some on dimmers and I am getting flickering. With a single D900 on a standard leading edge dimmer there is a barely discernible flicker when turned low, with two D900's there is a clearly discernible flicker and it starts a short while after turning them on even when the dimmer is on full.

I am aware that dimmers typically require 20W to function correctly and that a single D900 is less than that, but if this is my problem I should have the opposite effect than I do when putting two on one dimmer compared with one.

I have tried another (also leading edge) dimmer, so it isn't my switch. I've also discussed it with my colleague (who is a qualified electrician) and we don't have any obvious answer. Anyone have any ideas? I contacted Brightgreen a few days ago via their website, but haven't heard back yet.

I want to replace the rest of my downlights with D900s, because I really like them, but I'm holding off because my next group is a set of four on a dimmer and if the flicker is as bad or worse than the set of two....

Hi,

You could get your electrician to try a trailing-edge dimmer. Electronic power supply units often work better with this type.

Paul

Last year our supplier advised us there were flickering issues with them in WA. I don't know anything about it, just made us want to test them first.

Thanks, yeah, I thought about that as (I think?) trailing edge has a sharp drop, instead of sharp rise in current. He hasn't got one handy though, so I'd have to buy one. Thought I'd see if anyone knew anything for sure first.

That is correct. Interestingly even though the Brightgreen drivers (and many other electronic transformers) state compatibility with leading-edge dimmers, the Clipsal documentation for their 32E450L (leading edge) series specifically states not to use it with electronic transformers. The 32E450T (trailing edge) has compatibility with electronic transformers.

Paul

After Solanum's post I decided to test the two dimmable LEDs that I have - a Brightgreen D900 and another that I got from electricalsupply.com.au

The results were interesting. My test dimmer was a Clipsal C-Bus leading edge unit, as I am going to have C-Bus in my house. These dimmers are slightly different to a normal wall-plate dimmer as the light is never actually switched off, a small amount of current flows even at 0%.

The Brightgreen worked fine, with no sign of flicker, but it only dimmed down to about 30% (this is just my subjective opinion - I don't have a light meter) but was off at 0%.

The other LED had a greater range of dimming, down to about 10%, but still glowed when 'off' 0%. Plugging in both the Brightgreen and this LED at the same time resolved this problem.

Paul

Interesting, though it was when I attached two Brightgreen LEDs that I really got the flicker. When I have only one on a dimmer it is barely discernible and doesn't seem to start immediately either (which suggests it is getting worse as the LED driver warms up?).

I'm going to have another play when I get the chance, if I'm feeling rich I might get a trailing edge dimmer too and try that.

I will try it again tonight and leave it running for a long time and see what happens. Unfortunately I only have 1 Brightgreen. I did use my wife as the flicker evaluator - she is very sensitive to flickering lights and often has to leave shops due to flickering HID lamps - I don't notice until she points it out and then I can see it if I look closely.

Paul

With a single Brightgreen on an (old) leading edge dimmer, to see the flicker I turned it right down (I agree with you on the min being about 30%) and then left it on for several minutes. I had the two on one dimmer first, so I was looking for the flicker, but with a single LED it certainly wasn't obvious without looking for it. With two, the flickering starts after a few seconds and is eventually visible even with the dimmer on full.

Thanks for your testing and comments by the way!

Hi

I left the Brightgreen running for about an hour last night and didn't see any flickering at all.

Paul

Well, I did get a reply from BrightGreen, but it was simply a we haven't seen any problems, what's your dimmer (which is a fair enough response) and I will explore it further with them.

However, for the record today I bought an HPM trailing edge dimmer, and it works with no flicker. I don't know what is the problem with the two Clipsal leading edge dimmers I tried was. However, with this dimmer, the first 75% of turn does nothing and the dimming is all in the last 25% of travel. You can limit the amount of travel when installing the knob, but as the lights are using the last 25% only, that doesn't help much.

So I guess my experience is (to be on the safe side) don't use old leading edge dimmers with multiple installations of BrightGreen D900s. Maybe new ones are better, and trailing edge certainly seems to be OK. If I get anywhere with my correspondence with Brightgreen on this I'll report back.

Thanks to those who responded and tried their own dimmers for me.

My experience is the HPM trailing (bit of lag on turning dial though) and Clipsal universal both work the best on most LED products, the clipsal trailing edge can sometimes flicker along with the leading edge as you are finding. The issue isn't so much with the start up current but the way the dimmer phase cuts.

The CBus issue seems to be the residual current/voltage (we measured 50v on one system) that you mentioned, our old 12w model did the same thing (would glow once light is turned off) but once we increased our chip to 13w it has sorted out the issue.