[time-nuts] [OT] Ikea Lamp

[paul swed]

Clarke
Sorry to hear that you hurt your eyes. I suspect many are unaware of the
risk.
I have experimented with higher power LEDs but nothing like 7 watts so very
good to have learned something. I have to say even looking at the lower
power LEDs you get the feeling that looking straight on is not a good idea.

My wife used some of the new LEDs on a christmas tree this year. We didn't
like them and turned them off using just the traditional lamps. She now
understands what a point source is.
Also if straight on they were quite bright off angle 12 degrees they were
pretty dim.

I have tinkered for a while looking for effectively spread leds for panel
meters. I dislike changing lights in my radios. But the LED simply do not
spread light the way lamps do.

Like your idea of the flexible trouble light.

On Sat, Jan 30, 2010 at 12:55 PM, Brooke Clarke <brooke at pacific.net> wrote:

> Hi Paul:
>
> LEDs come in many flavors of white.  The ones called warm white can be very
> comfortable but they are not as bright as the plain white or cool white
> LEDs.
>
> Also high power LEDs can burn your eye.  Not because they emit UV but
> rather just because they are bright, like the Sun.
> http://www.prc68.com/I/LED.shtml#Atlas  This is a 7 Watt LED that burned
> my eyes.
>
> Wien's displacement law relates the wavelength emitted from a hot body to
> it's surface temperature.  For numbers for the Sun or a human see:
> http://www.prc68.com/I/Probeye.shtml#WaT
> Planck's law took another five years to relate frequency and surface temp.
>
> Have Fun,
>
> Brooke Clarke
> http://www.PRC68.com
>
>
> paul swed wrote:
>
>> IKEA and $39 per lamp. Sounds like some pretty good margin in the sale.
>> I guess these LED things will be main stream and save the world when we
>> see
>> them at walmart for $6.
>>
>> On my bench I converted to 60 watt halogen lamps compared to the 100 watt
>> lamp.
>> Equivalent color spectrum to the traditional lamp also. For as many hours
>> as
>> that light is on. I suspect I am saving some money in the long run.
>>
>> Curious are these lights truly white or do they tend towards a traditional
>> lamp spectrum.
>> Regards
>>
>> On Sat, Jan 30, 2010 at 8:15 AM, Didier Juges<didier at cox.net>  wrote:
>>
>>
>>
>>> Yes, it is frustrating, they have to be the last dinosaurs of consumer
>>> distribution.
>>>
>>> For me, the nearest store is 6 hours away, if I don't get stopped for a
>>> speeding ticket on the way...
>>> So I can't afford to be interested in what they may have for sale.
>>>
>>> Didier
>>>
>>>
>>>
>>>> -----Original Message-----
>>>> From: time-nuts-bounces at febo.com
>>>> [mailto:time-nuts-bounces at febo.com] On Behalf Of Brooke Clarke
>>>> Sent: Friday, January 29, 2010 3:07 PM
>>>> To: Discussion of precise time and frequency measurement
>>>> Subject: Re: [time-nuts] [OT] Ikea Lamp
>>>>
>>>> Hi David:
>>>>
>>>> Thanks for the link.  I like them.  The only problem is that
>>>> you can not order on line or by phone from Ikea and the
>>>> nearest store is over two hours drive away.
>>>>
>>>>
>>>>
>>>
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>
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