Which LED's work?

Trying to follow all the LED discussions here and I am totally confused as to what works and what does not.

Can you guys that have LED's installed post what you are using and what dimmer you have them on and any other special requirements you may have added to get them to work.

I am specifically interested in a MR16 replacement, but I am sure that we would like to see a list of all options here

Thanks

Mick

Lisf of confirmed working LED's
- Pierlite Starbust

 

Hello Mick
Yesterday I installed 6 x 12W Pierlite Starburst MR16 and the transformers they come with to into my existing fittings.
They replace the 6 x 50w halogen in my office which is 3.4m x 4.2m.
I have no light meaurement but they seem to be very close to 50w halogens as far as light output goes.
They are rated at 3000K but seem a bit cooler in colour than I would have liked.
The cooler colour temperature of the led is easily noticable in a side by side comparison to a halogen but once the whole room is done I would say the colour is not too cool and probably more suited to office tasks anyway.
They are connected to a L5508D1A 8ch leading edge dimmer.
From the data sheet they say you can connect from 1-6 transformers per channel on a leading edge dimmer and 1-36 per channel on the universal dimmer.
Mine are currently wired 1 per channel.
Dimming response is very much as I had from the halogen but unlike the halogen I tested them down to 0% without trouble.
On a 4 second ramp there seems to be some visible stepping during dimming but this is only just noticable and seems less noticable on a 12 second ramp.
In my instance the office has a floor above and there is an issue with clearance and cooling for halogens so the leds seem a good option.
The heatsink is quite tall so you might need to check clearance in some applications.

Visually, if you look side on at the fitting I would say the leds have a very slight blue tinge but this is not the case for the area illuminated.
If you look directly at the light, aside from burning your retinas out, the colour appears warmish and it is hard to distinguish the individual leds.
Once the lights are dimmed the 6 individual leds are clearly visible.
This is not as attractive as the sparkly, glowing ember feel which you get from a halogen, but I'm not sure how many people sit there staring at their lamps.
Unlike dimming CFL's the leds seem to hold their colour temperature while dimming.
The shadows cast on the wall are more diffused than the 60 dergee halogen but I would say the beam angle is roughly the same.
Since I have just spent over $600 in parts to replace the lamps in my office it would be hard to say I am happy but instead not too disappointed.
I havent done the sums on power savings and while they have a 3 year warranty their longevity is an unknown factor for me and it's hard to imagine that there will be a cost saving.
So even though I have only used them for 1 day I would say they work quite well.

 

Thanks for that info Ashliegh
I was considering changing them to one channel and wondering what it might do to the buzzing from the leading edge dimmer.
It's not buzzing any more than it was with the halogens and redbacks but the switchboard is 1 metre from my desk.

 

If you want a dimmer that is practically silent, irrespective of the load type connected, then I suggest you swap your DIN Leading Edge dimmers over for the DIN Universal dimmers. They are virtually silent, irrespective of the brightness setting.

1m from your desk... that's close enough to notice! I assume you don't have a microswitch on a cat flap controlling a relay in that cabinet!

 

Thanks Ashleigh and Newman
It was the first one I ever installed and I have been mindful of locating them since.
I thought I read somewhere that the universal dimmer might be quieter.
I have used the universal dimmer before and from memory it chose leading or trailing edge depending on the load.
If that is correct do you think 6 starburst transformers per channel would run on trailing edge and does it matter with regard to the buzzing?

 

Regarding the Starburst,
I think the colour temperature of the LED's is quite satisfactory compared to halogens but in my opinion they might not be suitable for colour critical applications.
The leftover pizza I had on Sunday morning looked ghastly on my desk.

 

Left-over pizza looks ghastly the following morning regardless of the light source!

If the colour of the light is an issue the Crompton XL LED is available in 2700K, 3000K, 4000K and 6500K colour temperatures. For reference, a regular halogen is ballpark 2800K and an IRC halogen is ballpark 2900K.

Reproduction of colours around red are the hardest part of the spectrum for LEDs to reproduce. The unit of measure for the quality of colour reproduction is a thing called CRI (Colour Rendering Index) where the maximum possible score is 100.

• The Starburst had a CRI of 83 and recently went up to 85.
• A typical halogen downlight has a score of about 99.
• A typical CFL has a score of about 70.
• A linear fluorescent will have a typical score of about 85.

The CRI is a really big area of lies in the LED market as it requires expensive equipment to verify. It's also one of the first areas the cheapie LED products sacrifice, although there is at least 1 big-name LED manufacturer that is dishonest in this performance aspect too.

If perfectly accurate colour reproduction is required, then you're realistically going to have to consider cyanosis-grade lamps. The light output is lower, but the colour reproduction is much more accurate.

 

Thanks, Newman!

It's always interesting to read your posts!

 

So far we have one on the list. Is that all there is that works.

I want to have a list that people can easily find and refer to instead of having to go through the numerous posts here on the forum.

Mick

 

That is what happens when you leave the vegetables out.