Cree announce 200L/W led production

[Martin Brown]

This is really very impressive with the same luminous efficacy as large
scale Low Pressure Sodium SOX lighting and at 1W / 25C too.

I suspect the very early adopters of "low power" LED lighting are going
to get their fingers burned. This new generation really will be truly
lower power LED lighting unlike the stuff being deployed now at 50L/W.
The big question is how long will the kit live in service?

Capacitors in switched mode PSUs still seem to die far too often

 

[[email protected]]

This is really very impressive with the same luminous efficacy as large
scale Low Pressure Sodium SOX lighting and at 1W / 25C too.

I suspect the very early adopters of "low power" LED lighting are going
to get their fingers burned. This new generation really will be truly
lower power LED lighting unlike the stuff being deployed now at 50L/W.
The big question is how long will the kit live in service?

Capacitors in switched mode PSUs still seem to die far too often

If you are referring to CREE MK-R LEDs
http://www.cree.com/led-components-and-modules/products/xlamp/arrays-directional/xlamp-mkr
Light output Up to 1769 lm @ 15 W, 85°C

= 118 lm/W

Still below (ugly) LP sodium lamps.

 

[Artemus]

Things are continually getting better with LEDs but in this case I think the
marketing guys have read a data sheet and got a bit ahead of themselves. AS I
understand it this is based on their MK-R series
http://www.cree.com/news-and-events/cree-news/press-releases/2012/december/mkr-intro

www.cree.com/mkr.

The 25C is a projected junction temp, in reality junction temp is around 85C in use
and efficiency nearer 100L/W, but I don't think that this will include the driver.
cheers
David

The marketing guys are doing what they always do. The phrase "up to"
just puts an upper bound, no matter how absurd, on something. The real
weasels use "up to" followed by "or more".
Art

 

[[email protected]]

Strange how the Brits consider Cree to be plural (Cree announce) whereas USians
would consider Cree to be singular (Cree announces.) I wonder when that
divergence happened.

It's more general than that. Brits consider a corporation to be
plural, where Americans consider it to be singular. I guess the
Europeans consider it to be a group of people (even though it may not
be), rather than an entity unto itself. Perhaps if we did the same,
there wouldn't be so many nuts around who want to "strip personhood"
from corporations.

 

[[email protected]]

In the DSL business, "up to" means "almost a third of, occasionally."

With my DSL line it's about "half of theoretical". There is no
"occasionally" about it.

 

[Martin Brown]

Strange how the Brits consider Cree to be plural (Cree announce) whereas USians
would consider Cree to be singular (Cree announces.) I wonder when that
divergence happened.

It isn't that clear cut at all. British English doesn't obsess about the
singularity or plurality of a corporate business entity. Both forms are
in common usage here. Google for "ICI announce" and "ICI announces"
finds a slight preference in the English speaking news media for the
USian style even in UK papers. Perhaps to avoid confusing Americans...

http://news.bbc.co.uk/onthisday/hi/dates/stories/august/22/newsid_2982000/2982042.stm

That is from 1966 and is ICI Announces (But then their full name
Imperial Chemical Industries was a clearly plural form). Other less
obviously pluralistic UK companies have a more even split.

Most companies with names ending "s" get treated as plural over here.

 

[Martin Brown]

The marketing guys always do that but even so these new LEDs look like
they are a factor of two better at power to light conversion than the
units currently being deployed by certain UK councils to "save energy".

In the DSL business, "up to" means "almost a third of, occasionally."

You are being fleeced. DSL speeds should be roughly speaking at least
half of what the theoretical line speed at your distance from the
exchange can support - assuming that you have a decent ISP. Throughput
when there is low contention should be roughly about 80% of sync rate.
Various calculators exist to compute attentuation to expected DSL rate.

Having long cables runs up on poles flapping in the breeze doesn't help.

Once the thing has trained it should deliver more or less steady
performance with some diurnal variation as MW interference comes and
goes with nightfall.

Crude rules of thumb but they should hold in most places. All bets are
off if you select a particularly bad ISP with massive contention ratios
and inadequate bandwidth external connections to the net.

Tek scopes used to deliver around 1.2x the specified bandwidth. Lately it's
about 0.85.

That is cheeky. 1.00x would be acceptable. 0.85x could leave them open
to return of goods in the UK as not fit for purpose.

 

[Fred Abse]

Strange how the Brits consider Cree to be plural (Cree announce) whereas USians
would consider Cree to be singular (Cree announces.) I wonder when that
divergence happened.

What do the Aussies do? I think Canadians tend to follow the US convention.

I think it's down to "journalistic house style".

Legally, a corporation is a single person, in most jurisdictions.