audio recording on IC -help wanted

Lostgallifreyan wrote:

Eeyore wrote

185 lumens using your figure of 2.2x times the reference brightness @
1A.

That should satisfy you then. You challenged me to cite proof of 176 mW as
if I was claiming too much. Are you now saying I'm wrong because it's not
EXACTLY 176 mW? If so I'm done discussing the matter.
No, it's fine. I hadn't previously noticed anything above about 150 lumens.

Graham
 
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:46929171.7393CA65@hotmail.com:

95% efficient power conversion from 5 to 32V
[snip]

However you did mention volts previously. It wasn't me who did that.
I see now, that's just loose phrasing by me that led you to misinterpret.

We both know that LED's are current driven. What I meant was that the input
can range between 5 and 32 volts. The conversion is to one of a variety of
preset fixed currents.
 
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:46929171.7393CA65@hotmail.com:

LEDS operate at lowish voltages. You tend to get lower efficiencies
with at lowish voltages, largely due to rectifier losses.

I doubt you'll much better 85% power conversion efficiency overall
from the AC line to the LED package actually. That would be a *very*
good figure.
LED drivers chain LED's to limit that problem. The one I bought can chain 7
LED's.
 
Eeyore <rabbitsfriendsandrelations@hotmail.com> wrote in
news:469291E7.3E162AD5@hotmail.com:

No, it's fine. I hadn't previously noticed anything above about 150
lumens.
It changes fast. :) I lost interest in LED's around the time of the 14
candela amber Toshiba 10mm types, because laser diodes were more fun.
Things have changed big time. I really do think they'll overtake CFL's so
fast that most of the public, especially legislators, will have no time to
adapt except in sudden jumps. They'll be thankful to do it too, once they
face the clamour of public dissent at having to throw away good light
fittings to suit the intended ban of tungsten lamps.

While something could stall the development of LED's there seems to be no
sign of that, if anything it will likely accelerate as technology further
blurs the distinction between LED and laser diode.
 
Lostgallifreyan wrote:

Eeyore wrote in
Lostgallifreyan wrote:

Even at >120°C the chips put out 70% of 25°C rated output, and I
doubt even ten closely packed emitters will get that hot if
convection can keep the mounts below 85°C. Ten emitters in a
lightbulb's space couldn't even get that hot unless they had less
than twice the efficiency of 100W tungsten lamps.

How do you work that out ?

Ten emitters of the current best type account for about 34W ! You'll
have a hell of a job keeping them below 70C or so in the space of a
current lighbulb ! Forced cooling would be essential and that's going
to be annoying. How many fans last 50,000 hrs too ? I'm sure they'd
get end up overheating through dust build-up reducing fan efficiency
too.

Ok, I think it will run hotter than I was suggesting, but you're forgetting
something too, a much greater chunk of that imput wattage will be emitted
as light, not heat, compared with tungsten lamps.
Only about 10%. There'll still be 34W to get rid of. And I forgot the
dissipation from the electronics too ! That'll be another ~ 5W so we're back to
where we were.

Graham
 
Lostgallifreyan wrote:

Eeyore wrote

LEDS operate at lowish voltages. You tend to get lower efficiencies
with at lowish voltages, largely due to rectifier losses.

I doubt you'll much better 85% power conversion efficiency overall
from the AC line to the LED package actually. That would be a *very*
good figure.

LED drivers chain LED's to limit that problem. The one I bought can chain 7
LED's.
Even then, the seondary rectifiers alone will consume about 5% of the power.

Graham
 
"Lostgallifreyan" <no-one@nowhere.net> wrote in message
news:Xns9969A7C8271D4zoodlewurdle@140.99.99.130...
"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in
news:4f0025414edave@davenoise.co.uk:

Most domestic lighting is used after dark and the colour temperature last
thing in the day is nothing like 4500k.


No. It's akmost certainly much hotter. While it's at its lowest
brightness,
the light of a clear day fading is biased extremely toward blue. The rods
in the eye make use of that, it's why greens and blues look brighter than
red flower petals at twilight.
It's really very orange in the evening, at least around here. The 5000K
fluorescent in my kitchen looks downright blue compared to evening sun.

6500K is the color of noon sun with clear sky, not something you encounter
often in urban areas.

Incandescent lamps that most people are accustomed to are very orange,
around 2700K.
 
In article <Xns996A702342E31zoodlewurdle@140.99.99.130>, Lostgallifreyan
wrote:
"Mr.T" <MrT@home> wrote in
news:4694982c$0$18304$afc38c87@news.optusnet.com.au:

Fine, that's why we all get a personal preference. However the spectrum
spread has as much to do with it as the stated color temperature IMO.


Yes. We are better at sensing discontinuities too, than we might think. We
can fool vision with RGB but when presented with purple and monochrome
violet we can see the difference without difficulty. Same goes for the
orange of laser or LED or low pressure sodium, or that made by mixing red
and green. We usually know when we're seeing a pure form of colour, and
it's only conditioning that allows us to easily accept things like TV
screens. (Which chop out all red below about 635 nm, as it happens, as
well as most of the rest of the spectrum).

As far as natural light goes, we are best satisfied by a true continuum
because we adapted to that before we evolved eyes, as such. Take a look at
a Cree or Luxeon LED carefully reflected in a CD. Now do the same with a
CFL. The LED's might be a tad skewed in their distribution but so is
daylight, usually, and LED's make a much better continuum than CFL's do. If
CFL's could do better they probably would, but I haven't seen one that
does.
I have been happier with the color rendering of CFLs than that of most
white LEDs. I have found most white LEDs to make reds and greens appear
duller. I have also seen the color-dulling effect of most fluorescents
with color rendering index outside the range of 82-86 (though high is
better than low). The key here appears to be ratio of yellow content to
red and green content.

- Don Klipstein (don@misty.com)
 
don@manx.misty.com (Don Klipstein) wrote in
news:slrnf99t55.p3f.don@manx.misty.com:

As far as natural light goes, we are best satisfied by a true
continuum because we adapted to that before we evolved eyes, as such.
Take a look at a Cree or Luxeon LED carefully reflected in a CD. Now
do the same with a CFL. The LED's might be a tad skewed in their
distribution but so is daylight, usually, and LED's make a much better
continuum than CFL's do. If CFL's could do better they probably would,
but I haven't seen one that does.

I have been happier with the color rendering of CFLs than that of
most
white LEDs. I have found most white LEDs to make reds and greens
appear duller. I have also seen the color-dulling effect of most
fluorescents with color rendering index outside the range of 82-86
(though high is better than low). The key here appears to be ratio of
yellow content to red and green content.
There is a sharp dip in green in the LED's. I agree it's not nice, nor is
the muted red. It's still a continuum though, and if improved will be
extremely easy to live with. Right now it's almost discontinous because the
dip is so great, but the discontinuity in CFL's seems very un-natural to
me, I notice it especially if I'm carrying something brightly coloured
between rooms. There's an almost disturbing 'filtration' effect on the
various colours. Some of my CFL's are way too heavy in red too. It's not a
pleasant colour, it's sickly, it makes normally innocous marks like pine
resin under pain on wood look like inflamation on diseased skin.

I don't think the key is any specific colour absence or presnce, but the
presence of any sharp absence. CFL discontinuities drop out like digital
bits, but those of LED's are like analog curves, and inherently easier to
compensate for.
 
"Lostgallifreyan" <no-one@nowhere.net> wrote:

First, how can a hotter temperature be cold??
Sunlight at high noon is considered "cold" lighting, even though the
temperaure of the light is at its highest. It's just semantics.

I bet we could get used to 'cold' light plenty fast so long as we
weren't
actually cold ourselves.
I doubt anyone prefers indoor lighting at 6500 K during a summer night.
It's stark lighting regardless.

Conversely, Dickens and many others have commented
on the bleakness of a small flame when there isn't enough heat to warm
the
people who need it. It really has to do with our ambient conditions,
not
direct colour perceptions at all.
Disagree. I think the bleakness Dickens refers to in this example is
unrelated to color temperature.

Bert
 
"Lostgallifreyan" <no-one@nowhere.net> wrote in message
news:Xns996AEC22BDD66zoodlewurdle@140.99.99.130...
don@manx.misty.com (Don Klipstein) wrote in
news:slrnf9ajqg.497.don@manx.misty.com:

But if the light level is neither in kilolux nevels nor a recent
uptick
from something lower, I find daylight to usually have no warmth or
"cheer".

If the ceiling is dark but the windows are bright, then things can
look
cheerful - sometimes - for some reason.


I mentioned contrast earlier, and I wonder if it might be this. I have an
odd colour scheme on my monitor, a kind of inversion of usual practise. I
call it 'panel lights'. It has black window objects, white and orange text
on them, the text backgound is a blue-biased mid grey, text black. Desktop
is deep blue with a pattern like dark water seen from a boat at twilight,
but saturated strongly, icon text there is like blue flame. Title bars are
green like plastic backlit by fluorescent light with red text. I like
programs with buttons that use colours well and illuminate like lights on
the black toolbars. Menus are yellow on a grey brown background. When
working on a full-screen text edit, it looks like a monochrome TV framed
by
illuminated panels.

What I'm getting at is that this thing has both kinds of colour, 'hot' and
'cold', and most of all, strong contrasts. Some would find it as garish as
a fairground. I find it comforting the same way I find firelight
comforting. It keeps me calm yet aware for long periods while working.
Similar lighting tricks keep air pilots awake on night flights. (That's
partly the basis of the name I give that scheme).

Most colour schemes I see on computers are varieties of dark text on pale
backgrounds. I don't care if they're warm flamelike backgrounds or cool
fern greens and icy blues, I find them ALL distracting, stressful, and the
executive class adlanders white pages and thin grey text and pastel shades
are the very worst.

Ok, so I'm weird, but that's still a natural take on lighting. It shows
that there's a lot more to this than colour temperature. Contrast is
important too, as is the ratio of light to dark, and of object to space,
and suggestion plays a big part. It's very hard to be scientific about
such
things, so maybe we shouldn't be trying too hard.

I'm still having a hard time adjusting to the fact that an SI unit, the
Lumen, is based on a statistical consensus, yet is placed alongside
hallowed units like the amp and the volt and the watt which seem as
immutable as 2+2 equalling four. Trying to get objective about what
colours
are 'right' for us to accept and discussing it as if it is a hard science
is more weird to me than suggesting that the lightbulb is a form of magic.
I suspect that your liking of odd colour schemes, harps back to distant
memories of your early life on Gallifrey, with its twin low luminosity suns,
and before you became 'lost' ... ;~}

Arfa
 
"Arfa Daily" <arfa.daily@ntlworld.com> wrote in
news:WSdli.34381$KE1.17442@newsfe1-win.ntli.net:

I suspect that your liking of odd colour schemes, harps back to
distant memories of your early life on Gallifrey, with its twin low
luminosity suns, and before you became 'lost' ... ;~}
Yes, yes that would be it. >:) The high council didn't build the Panopticon
for nothing, you know... All those lights in the dark, hypnotic.
 
"Albert Manfredi" <albert.e.manfredi@nospam.com> wrote in
news:JL1E3w.JBu@news.boeing.com:

Disagree. I think the bleakness Dickens refers to in this example is
unrelated to color temperature.
That was the point. Don't you see? That's exactly why it isn't the colour
temperature that really defines our reactions at all, it's the context.
 
"Albert Manfredi" <albert.e.manfredi@nospam.com> wrote in
news:JL1E3w.JBu@news.boeing.com:

Sunlight at high noon is considered "cold" lighting, even though the
temperaure of the light is at its highest. It's just semantics.
Semantics? As in the usual current usage meaning 'empty meaning, splitting
hairs'? That's only true if you ignore context. That's what gives it
meaning. No-one in their right mind would consider high noon in the outback
to be 'cold' either literally OR figuratively.
 
On Thu, 12 Jul 2007 11:58:50 GMT, Lostgallifreyan <no-one@nowhere.net>
wrote:

Moonlight's color temperature at its highest is about 4000.

I haven't seen a reference for this, but even assuming it is so, it's
still higher than many people here prefer it would seem.


Nice way to test: Take a camera and tripod, do a long exposure shot of a
moonlit scene. Then view the phtot on a monitor in a context you know. I
haven't done this but I think it will bear out the claim that the moon's
light is brownish, as it looks when you look directly at it. The blue comes
from a combination of scattered light and scotopic sensitivity to the blue
part of its spectrum.
You may well be right. But I wouldn't rely too heavily on the colour
accuracy of a long exposure :)
 
Laurence Payne <lpayne1NOSPAM@dslDOTpipexDOTcom> wrote in
news:sb6c939lm4g9d2fk61bsd92ivoi5lkl119@4ax.com:

On Thu, 12 Jul 2007 11:58:50 GMT, Lostgallifreyan <no-one@nowhere.net
wrote:

Moonlight's color temperature at its highest is about 4000.

I haven't seen a reference for this, but even assuming it is so,
it's still higher than many people here prefer it would seem.


Nice way to test: Take a camera and tripod, do a long exposure shot of
a moonlit scene. Then view the phtot on a monitor in a context you
know. I haven't done this but I think it will bear out the claim that
the moon's light is brownish, as it looks when you look directly at
it. The blue comes from a combination of scattered light and scotopic
sensitivity to the blue part of its spectrum.

You may well be right. But I wouldn't rely too heavily on the colour
accuracy of a long exposure :)
I guess not. Probably weighted by gamma correction or something. Worth
trying a few different timings to see what happens though. Maybe with some
small faint diffused blackbody source in frame as a reference.

Apart from correction added, there is no reason for colour to fail, because
photons are quanta, each one will be treated the same by filters no matter
how few or how many. The real danger is overexposure saturating any of the
filtered sensors.
 
Lostgallifreyan <no-one@nowhere.net> wrote in
news:Xns996B87D296F6Ezoodlewurdle@140.99.99.130:

The real danger is overexposure saturating any of the
filtered sensors.
Sorry, that's daft. It's modelled. :) But if you have enough the camera
adds them up and the values can clip, which amounts to same thing.
 
In article <4695f220$0$14986$afc38c87@news.optusnet.com.au>,
Mr.T <MrT@home> wrote:

"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in message
news:4f00b9ac69dave@davenoise.co.uk...
That's more to do with the relative sensitivity of film color layers
etc.
They are specifically balanced for Daylight or Tungsten, and are
wildly innacurate when used with the wrong light source.

In which way are they 'inaccurate'? They will look wrong to the eye on
a 'cut' but as with real life if all shots are matched the eye will
accommodate.

Not so. They ARE wrong. The relative densities of the individual film
layers will be quite innacurate when exposed with the wrong light.
You conveniently snipped the part about video. And a daylight film can
also look 'wrong' when taken in daylight of the wrong colour temperature.
Which can be corrected by filters when taking the pic or processing it.

The monitor you're reading this on is unlikely to match
*exactly* another one in colour temperature but will look ok to the
individual. The eye compensates, as I said, as it must do given that
daylight changes. Unless it has a reference to match to.

Which is everything else within your field of view. Only if *everything*
changes will the *brain* correctly compensate.
Not so - do you change the colour temperature of your TV or monitor
according to the ambient light? The brain focuses on the important part
after time - within reason.

Err, yes. That's what I said. But it doesn't react instantly. Hence it
notices a sudden change in colour temperature. Like switching on 4500K
lights in a house when it gets dark.;-)

So a couple of minutes readjustment is abhorent to you?
Doesn't bother me too much.
Fine - but you're in a minority if you like cold domestic lighting.

Have you never wondered why most prefer the colour temperature of
tungsten for domestic lighting?

No, as I already stated it was simply conditioning from fires, candles,
oil lamps and tungsten filament globes.
Fluorescent lights have been around for a long, long time. And early ones
were all cold compared to tungsten. People could easily have got used to
them for domestic light, but very few chose to.

Have you ever wondered why people aren't bothered by the change from
daylight, or in fact are able to wear coloured sun glasses, but can
readily pick an off balance color photo?
Can they? Depends on their skills. Have you never noticed how many people
are happy with a TV where the grey scale is miles out?

--
*Sometimes I wake up grumpy; Other times I let him sleep.

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
In article <Xns996B90A4AD808zoodlewurdle@140.99.99.130>,
Lostgallifreyan <no-one@nowhere.net> wrote:
Back to lights: I refer again to the point that reading and detailed
indoor hobbies need shortwave light to avoid eye strain, and the only
reason people turn up the tungsten is because that's the only way they
actually get enough of the shortwave light they need.
*Continuous spectrum* light is certainly an advantage for most work or
hobbies. Which is where many so called high efficiency light sources fail.

--
*Marriage changes passion - suddenly you're in bed with a relative*

Dave Plowman dave@davenoise.co.uk London SW
To e-mail, change noise into sound.
 
"Dave Plowman (News)" <dave@davenoise.co.uk> wrote in
news:4f01424888dave@davenoise.co.uk:

*Continuous spectrum* light is certainly an advantage for most work or
hobbies. Which is where many so called high efficiency light sources
fail.
Well yes, but that's exactly why I'm advocating the new LED's Their spectra
ARE continuous. They dip a bit in the breen, and the far red, but they're
no-where near the gross discontinuity seen from a CFL.
 

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