What is the purpose of AC line powered LED lighting products?

[ITSME.ULTIMATE]

Something like this:
http://www.nuwai.com.tw/new_products/dk-200ld.htm

I hear something like that is not inexpensive and when you consider the
already poor efficacy of LED's combined with series resistor and wall-
wart, the efficacy is probably the same as or worse than a low wattage
incandescent lamp.

Since the efficacy under reduced input power is not a concern as it is
for battery powered application, I can't find the purpose of low output,
poor efficacy, high cost, AC powered LED light fixtures.

Am I missing something here?

 

[Clive Mitchell]

Something like this:
http://www.nuwai.com.tw/new_products/dk-200ld.htm

I hear something like that is not inexpensive and when you consider the
already poor efficacy of LED's combined with series resistor and wall-
wart, the efficacy is probably the same as or worse than a low wattage
incandescent lamp.

Since the efficacy under reduced input power is not a concern as it is
for battery powered application, I can't find the purpose of low
output, poor efficacy, high cost, AC powered LED light fixtures.

Am I missing something here?

The bogus selling point is the long life. This doesn't always pan out
in reality.

The good points are that coloured LED lamps are pretty good for
decorative applications at low intensity levels since the LEDs do offer
a higher colour output than a filtered low colour temperature source,
especially for blues and greens.

They've still not cracked "warm white" though.

 

[[email protected]]

| In message <[email protected]>, ITSME.
|>Something like this:
|>http://www.nuwai.com.tw/new_products/dk-200ld.htm
|>
|>I hear something like that is not inexpensive and when you consider the
|>already poor efficacy of LED's combined with series resistor and wall-
|>wart, the efficacy is probably the same as or worse than a low wattage
|>incandescent lamp.
|>
|>Since the efficacy under reduced input power is not a concern as it is
|>for battery powered application, I can't find the purpose of low
|>output, poor efficacy, high cost, AC powered LED light fixtures.
|>
|>Am I missing something here?
|
| The bogus selling point is the long life. This doesn't always pan out
| in reality.
|
| The good points are that coloured LED lamps are pretty good for
| decorative applications at low intensity levels since the LEDs do offer
| a higher colour output than a filtered low colour temperature source,
| especially for blues and greens.
|
| They've still not cracked "warm white" though.

Nor have they cracked continuous spectrum white. But I think there could
be a potential by combining enough LEDs of a variety of different wavelengths
to get close enough for purposes like my use of task lighting.

 

[Clive Mitchell]

Nor have they cracked continuous spectrum white. But I think there
could be a potential by combining enough LEDs of a variety of different
wavelengths to get close enough for purposes like my use of task
lighting.

Which would be easy in a mains powered LED lamp because all the LEDs are
wired in series.

 

[ITSME.ULTIMATE]

The bogus selling point is the long life. This doesn't always pan out
in reality.

The good points are that coloured LED lamps are pretty good for
decorative applications at low intensity levels since the LEDs do offer
a higher colour output than a filtered low colour temperature source,
especially for blues and greens.

They've still not cracked "warm white" though.

But they aren't color decorative LED lights. They're LED based desktop
task lamp.

 

[Clive Mitchell]

The luxeon 'warm white' ones look quite warm to me. Am I just not
critical enough?

Send me one and I'll tell you.

 

[Ian Stirling]

Send me one and I'll tell you.

http://www.luxeonstar.com/item.php?id=391&link_str=208&partno=LXHL-BW03

Mention my name, and you'll get... Absolutely no discount at all

The blue peak is quite suppressed, to maybe half the level of the peak
emission which is at 640nm, with the only dip being a modest one at
500nm.
The rest is 'sort of' black body.
Compared to a normal one, the difference is really visually striking.

Hmm.
Surprisingly cheap.
$2/W or so, from that site, (US, for 3W ones) and no penalty for ones.

Hmm. The K2 packaged white (not warm white) has a 40lm/W at 25CTj.
which at a slightly realistic outside of package temperature (in som apps)
of 40C, for 38lm/W minimum, operating at 1W, not bad, at $6 or so.
(They don't specify minimum output at '3W'.)