Hi,I'm late to the thread (as usual), but have looked at these LED's in the
past. It was for a biotech imaging application. There are two types, a
red/green/blue cluster or a blue / near UV LED with a white phosphor. These
phosphors seem to have a fairly continuous spectrum, at least compared
The speed isn't terribly surprising since the phosphor used is
actually a scintillator.
Unlike phosphors scintillators don't have long decay times so there is
no afterglow like that from a phosphor.
The IKEA LED lamp output may not be significantly modulated if the wall
wart constant
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-
J. Forster wrote:
The attached spectrum is from a Circline Fluourescent that screws into a
table lamp.
This is the type of spectrum I would like to avoid.
Continuous spectrum and warm white is my preference for normal light.
Fluorescent sky blue white is what I don't want.
Cheers,
Magnus
d.sei...@comcast.net wrote:
I took apart the last dead one just for that purpose. I initially eyed the 105deg Al cap, but it was dead, along with one of the xstrs (hole in package). The film caps, diodes and fuse are still good too. As is the tube- don't know what I'll do with that.
Sounds to
Also they are very sensitive to heat, so do not use them in an enclosed
fixture.
I have been burned (figuratively) with these two gotchas, there may be more.
The one that lasts the longest in my house is the outside light at my back
door. It is turned on once a day around 6-7 PM and off in the
J. Forster wrote:
Attached is a spectrum of a white LED Flashlight. My diode
spectrometer
does not go further than the limits shown.
While this may be stretching the limits of time-nuts...
I think I saw a question asking what was used to measure the recently
posted LED spectra but other
Hi
At the cost target on those bulb's it's always a race to see who dies first.
The same can be said of conventional fluorescent fixtures. I have some big ones
in the shop downstairs. The no name electronic ballasts that came with them all
died in the first two years. I replaced them with
I have dissected many dead CFL's, and the key component failure
is the 10uf 350V electrolytic capacitor. Most of these bulbs caution
against using them in a base up configuration which of course is
how most of my CFL's are operated.
I have several rooms that are lit exclusively with CFL's,
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
Hi
I have a store some 5km away... but anyway, it seems its possible to
webshop at least in Ikealand.
http://www.ikea.com/ms/sv_SE/customer_service/how_to_e-shop/how_to_e-shop.html
--
Björn
Yes, it is frustrating, they have to be the last dinosaurs of consumer
distribution.
For me, the
I'm curious to know a little more about what was used to measure
the LED spectra. Not familiar with a diode spectrometer and
Google is not being very helpful. The last time I measured optical
spectra was a long long time ago using a PE UV/Visible
spectrophotometer in the early days of
For those who don't speak swedish try:
http://www.ikea.com/ms/en_GB/customer_service/how_to_e-shop/how_to_e-shop.h
tml
Dave
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of b...@lysator.liu.se
Sent: 30 January 2010 16:01
To:
Robert Atkinson wrote:
Hi,I'm late to the thread (as usual), but have looked at these LED's in the past. It was for a biotech imaging application. There are two types, a red/green/blue cluster or a blue / near UV LED with a white phosphor. These phosphors seem to have a fairly continuous
In general I agree, but the blue-white LED flashlight is pretty useful for
looking inside electronics.
-John
=
J. Forster wrote:
The attached spectrum is from a Circline Fluourescent that screws into a
table lamp.
This is the type of spectrum I would like to avoid.
Chuck Harris wrote:
I bought some of the LED replacements for Edison bulb incandescents, and
they have an afterglow that lasts for several minutes. It is very much
dimmer than when they are turned on, but is there none the less.
-Chuck
I got one of these so called 2D fluorescent tubes in a
Dr. David Kirkby wrote:
Chuck Harris wrote:
I bought some of the LED replacements for Edison bulb incandescents, and
they have an afterglow that lasts for several minutes. It is very much
dimmer than when they are turned on, but is there none the less.
-Chuck
I got one of these so called 2D
The Spectrometer I used is an Ocean Optics HR2000. It's a small box about
2 x 4 x 6 and has a FO input and a USB connection. It is powered from
my laptop via the USB port.
I bought mine at an MIT Flea Market last summer. The SW is available from
the manufacturer.
I don't recall what I paid, but
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.
Or, possibly, your radiant personality :). - Mike
Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731
732-886-5960
-Original Message-
From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On
Behalf Of Dr. David Kirkby
Sent: Saturday, January 30, 2010 12:47 PM
To:
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
Dr. David Kirkby wrote:
I should have added, it carried on glowing for some time after I got
home too. At that point, I was well away from the train lines, though we
do have 11 kV overhead cables around 30m from the house. It eventually
stopped glowing so I assume it was the presence of the
DNA sequences are also similar to sequential code and have something
similar to procedures. There are genes that control
which procedures are active, and which are not. So there is a bunch
of zombie code that was active in some distant past, but not used now.
If by mistake some of this
If you care about accurate colour rendering, stick with incandescent,
preferably halogen. White LEDs are actually blue LEDs coated with a
phosphor that absorbs some of the blue light and emits approximately
yellow instead. If you look at the spectrum, you'll see a broad yellow
peak and a
Hmm. Has anyone built a strobe light using LEDs instead of a xenon
flash tube? I can see the appeal of building something that doesn't
need high voltage to fire or trigger the tube. Yes, you probably
couldn't get as much light as a big Xenon tube, but there are
applications where you don't
I have some Philips LED halogen downlighter replacements. They are rated at 3W
and produce a noticeable glow when OFF. They are on a 2-way circuit and the
stray capacitance of the wiring allows enough current for a faint glow.
Robert G8RPI.
--- On Sat, 30/1/10, Chuck Harris cfhar...@erols.com
There are also large differences in rated lifetime; look at the fine
print on the package.
I've had some early Philips units that I used in a timer-driven lamp;
they were on for hours every day. The lamp lasted for years and years
and I eventually threw it out because it had gotten dim (the
Hi Dave,Yes I have. There was also a design in NutsVolts a while back.
Generally if you keep the duty cycle low (1:20) and pulses short (20ms) you
can push most LED's to about ten times their maximum continuous rated current
without ill effect. Looking at the continuous and pulse ratings of IR
Hi Dave:
LEDs are used on many cell phone cameras in just that way. The data
sheets for the LEDs have the pulse use specs.
At: http://www.sd36.bc.ca/sulhts/departments/elx/p/elec.html
scroll down to the Boy Scout Motor and notice a common LED held by two
wires that's being used as a strobe
Chuck Harris wrote:
I bought some of the LED replacements for Edison bulb incandescents, and
they have an afterglow that lasts for several minutes. It is very much
dimmer than when they are turned on, but is there none the less.
-Chuck
Bruce Griffiths wrote:
The speed isn't terribly
I remember hearing about a law suit in an engineering law class I had to
take way back when. It seems a farmer had a long fence running under and
parallel to a high tension distribution line. He had hidden a copper line
in it and was harvesting enough power to operate most of his farm
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.
The classic clear plastic package with a round dome actually makes a pretty
good lens.
Most/many LEDs are
Hal Murray wrote:
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.
The classic clear plastic package with a round dome actually makes a pretty
good lens.
Chuck Harris wrote:
I have several rooms that are lit exclusively with CFL's, and I find
that for best life, I have to leave them on all the time. That is what
EPA has found too! CFL's may take less power for a given illumination,
but the owners leave them on far longer than incandescent,
J. Forster wrote:
I believe these particular units came from a biomedical analyzer of some
sort. The gratings (hence the dispersion) can be changed at the factory,
but it costs something like $500 last seen.
I work with a fellow who makes custom gas discharge lamps (you need a
spectra, he
NeonJohn wrote:
Chuck Harris wrote:
I have several rooms that are lit exclusively with CFL's, and I find
that for best life, I have to leave them on all the time. That is what
EPA has found too! CFL's may take less power for a given illumination,
but the owners leave them on far longer
Hi,
I picked up a nice big clock that has self winding clock co. New York
and western union on the face.
After some research on the web I connected a 3V battery up and it wound
itself OK.
Fiddled with the orientation a bit to get the pendulum swing balanced and
it seems to be running OK now.
Oh I am certain that they can measure the losses, especially today.
I disagree that harvesting the fields from a hundred feet away is
theft, though. Especially if it is on your own property.
The easements on my property give the power companies the right
to come onto the property and maintain
Wait until they find out there is arsenic in LEDs!
cheers, Neville Michie
On 31/01/2010, at 7:50 AM, NeonJohn wrote:
Chuck Harris wrote:
I have several rooms that are lit exclusively with CFL's, and I find
that for best life, I have to leave them on all the time. That is
what
EPA
NeonJohn wrote:
Chuck Harris wrote:
I have several rooms that are lit exclusively with CFL's, and I find
that for best life, I have to leave them on all the time. That is what
EPA has found too! CFL's may take less power for a given illumination,
but the owners leave them on far longer than
Bruce Griffiths wrote:
If the intention is to cleanup the mercury rather than just the glass
and relatively non toxic phosphor then the cleanup procedure is contrary
to the method outlined in:
http://www.p2pays.org/ref/15/14605.htm
If one is paranoid about mercury spills sprinkling the
According to the paper that was linked earlier, there are 3 types of
fluorescent bulbs, some have no heater at all and are started with a high
voltage pulse that causes accelerated damage.
Those suffer from the most life reduction when cycled.
Those with the always on heater suffer the least, but
Corby if you just found it consider lubricating it before running it.
I have used transmission oil very very little on the higher speed gear
bearing points.
A light/medium grease on the springs. I speculate a solenoid winds a
spring.
I have a number of other pulse clocks Standard electric.
They
Ken, at Ken's Clock clinic http://www.kensclockclinic.com/ has a good deal of
information about Self-Winding Clock Company clocks, as does our own Brooke
Clarke http://www.prc68.com/I/SWCC.shtml.
I have two of these beasts, powered by a replica #6 battery from Ken's Clock
Clinic, that contains
Corby, I've been working with and collecting self-winding clocks for about
15 years and have about 20 that are synchronized hourly to a 2 second pulse
from an Oncore GPS receiver connected to a Parallax BS2. In order for the
synchronizer to function properly, the minute hand must be mounted so
OK. I'll look for the guy's contac info, but it might take a day or two.
-John
===
J. Forster wrote:
I believe these particular units came from a biomedical analyzer of some
sort. The gratings (hence the dispersion) can be changed at the factory,
but it costs something like $500
Just about every doctor's surgery or emergency room more than about 15 years
old will have had more than one thermometer broken in it. I'm sure there are
lots of little balls of mercury lurking in carpet fibres or between tiles in
those environments. It doesn't seem to have surfaced as an
Frankly, I think today if you breathe, pee, poo, or do ANYTHING at all you
are likely breaking some law, silly or otherwise.
FWIW,
-John
===
[snip]
As the laws are currently written, if you intentionally pour any amount
of gasoline, or paint thinner onto the ground you are committing a
It is known (for whatever reason) as flowers of sulphur by gardeners
medical practitioners (althernative and conventional) and others outside
the US.
http://www.websters-online-dictionary.org/fl/flower+of+sulphur.html
http://mysite.du.edu/~jcalvert/phys/sulphur.htm
Sulphur flower is ground sulphur raw sulphur. Flowers of sulphur is
precipitated out of sulphuric acid.
The distinction is subtle, but can be quite deadly if you do pyrotechnics.
Flowers of sulphur can be highly acidic and reacts violently with chlorate
compounds.
-
Corby,
Getting hard to find a posting about time amid all the OT stuff.
Do some more research. Maybe ask the NAWCC librarian. Or send it to
me and I'll find out, then return it to you in the same box. I'll
pay return shipping for the experience. I have no room to keep large
clocks. Do have a
Among chemists, it's flour of sulpher. Flowers is an (incorrect archeic)
popular name, like quicksilver.
-John
===
It is known (for whatever reason) as flowers of sulphur by gardeners
medical practitioners (althernative and conventional) and others outside
the US.
When did this list become a discussion of Chemistry?
Is there a time list I can join?
Not that I've never been off topic, or never learned something
from an OT discussion, but this brings to mind dead horses and
the beating thereof. I'll bet there is a better list for this
subject, and that it's
The connection is alchemical,
Don
- Original Message -
From: Bruce Griffiths bruce.griffi...@xtra.co.nz
To: j...@quik.com; Discussion of precise time and frequency measurement
time-nuts@febo.com
Sent: Saturday, January 30, 2010 8:53 PM
Subject: Re: [time-nuts] Conducting Bench Top
Max wrote:
I remember hearing about a law suit in an engineering law class I
had to take way back when. It seems a farmer had a long fence
running under and parallel to a high tension distribution line. He
had hidden a copper line in it and was harvesting enough power to
operate most of
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