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 :(
No worries, just use a couple of 100H inductors, one each before and after the bridge rectifier. ;)
Cheers
Phil Hobbs
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
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
If you are referring to CREE MK-R LEDs
= 118 lm/W
Still below (ugly) LP sodium lamps.
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.
in use
driver.
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
in use
driver.
In the DSL business, "up to" means "almost a third of, occasionally."
Tek scopes used to deliver around 1.2x the specified bandwidth. Lately it's about 0.85.
USians
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...
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.
the
Iin use
driver.
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".
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.
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.
YAwn. Undergond phone cables are the norm, and a lot of areas are now FIOS. The underground cable in some areas is so old it's starting to cause problems.
Yup, our 19 year old neighborhood just got a makeover to fiber. ...Jim Thompson
Martin seems to think US technology is still like those 1920 photos of hundreds of single conductor pairs strung down city streets.
Probably. I last lived at a house with overhead electric and phone about 43 years ago. ...Jim Thompson
USians
The usage with respect to sports teams also sounds inverted to our ears over on the west side of the pond. A sample of recent headlines from the BBC website:
Arsenal plan to hold more talks with Theo Walcott next month in an attempt to keep the 23-year-old at the club.
Liverpool are ready to go head-to-head with Newcastle for 21-year-old Valenciennes central defender Nicolas Isimat Mirin.
Blackburn have added 32-year old MK Dons boss Karl Robinson to their managerial wish-list.
Where usage over here would typically be "Arsenal plans ...", "Liverpool is ...", and "Blackburn has ...".
USians
I think it's down to "journalistic house style".
Legally, a corporation is a single person, in most jurisdictions.
Ewarly '70s for me, but the house was wired with twisted three conductor, cotton cover station wire. Probably the original drop from when it was built in 1945.
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