Extend Remote signal around corner of the wall???
OurFamily
room through the doorway and around the corner. What is the best way to
extend the remote control or make sure that it will work in this way. Any
ideas. Not that far but the corner I think will cause a problem.
Mark Lloyd
wrote:
There are the IR/RF/IR "pyramids" but they are unreliable. I use the
Xantech IR extender system (http://www.smarthome.com/8197.html).
--
Mark Lloyd
http://go.to/notstupid
http://notstupid.laughingsquid.com
"religion is a socio-political institution for the
control of people's thoughts, lives, and actions;
based on ancient myths and superstitions perpetrated
through generations of subtle yet pervasive
brainwashing."
Larry Nielsen
Larry
"OurFamily" <NotR...@ptd.net> wrote in message
news:0_97a.6136$hj.19...@nnrp1.ptd.net...
Eric Gauthier
>On Wed, 26 Feb 2003 21:05:00 GMT, "OurFamily" <NotR...@ptd.net>
>wrote:
>
>>I am looking to place my stereo,vcr, and dvd in the room next to our family
>>room through the doorway and around the corner. What is the best way to
>>extend the remote control or make sure that it will work in this way. Any
>>ideas. Not that far but the corner I think will cause a problem.
>>
>
>There are the IR/RF/IR "pyramids" but they are unreliable. I use the
>Xantech IR extender system (http://www.smarthome.com/8197.html).
I use the pyramids to control my audio stack from my kitchen. I have
never found it to be unreliable. Although, the two pyramids are only
about 30 feet away from each other. Do you mean that the RF is
unreliable?
I am sure that the Xantech is a more robust, but it isn't really an
optimal (or cheap) solution for trying to "get the remote to work
around a corner" since you need the coax (or do I misunderstand how it
works?).
I think my pyramids were about $35 for the set, and they work fine for
my application.
-Eric
----------
Remove "I HATE SPAM" to reply
Richard Cochran
> On 26 Feb 2003 15:17:13 -0600, Mark Lloyd <mll...@godmail.com> wrote:
>
> >On Wed, 26 Feb 2003 21:05:00 GMT, "OurFamily" <NotR...@ptd.net>
> >wrote:
> >
> >>I am looking to place my stereo,vcr, and dvd in the room next to our family
> >>room through the doorway and around the corner. What is the best way to
> >>extend the remote control or make sure that it will work in this way. Any
> >>ideas. Not that far but the corner I think will cause a problem.
> >>
> >
> >There are the IR/RF/IR "pyramids" but they are unreliable. I use the
> >Xantech IR extender system (http://www.smarthome.com/8197.html).
>
> I use the pyramids to control my audio stack from my kitchen. I have
> never found it to be unreliable. Although, the two pyramids are only
> about 30 feet away from each other.
Agreed.
I have a set that are about 35 feet from each other, and they
always work perfectly, except when I move the furniture around
and obstruct the light path between the receiving pyramid and
my stereo.
While I'm sure a wired solution would be preferable for many
situations, especially when covering long distances, the
pyramids are a good inexpensive solution with minimal
installation hassles for situations where the distances
aren't far.
--Rich
David Petrone
Dave
"Larry Nielsen" <larion...@bellsouth.net> wrote in message
news:S2e7a.123309$Kj2.1...@fe02.atl2.webusenet.com...
Dave Houston
"David Petrone" <dav...@advacon.com> wrote:
Jack Ak
in my TV stand isn't really seeing the IR signal from the remote in my hand.
IR CAN be reflected by a mirror. I just now tested that theory.
IR can be reflected by a light colored surface. IR is light in the non visible
spectrum. There is no reason to believe that IR light would not pass through
common glass.
Infrared film couldn't be used in cameras if IR light didn't pass through glass.
"Dave Houston" <dhou...@fuse.net> wrote in message news:3e5ed612...@nntp.fuse.net...
Rod Speed
> IR does not pass through glass.
The IR used by remotes does.
Rod Speed
G. Morgan <wacog...@yahoo.com> wrote in message
news:k7nt5v410f82a889i...@4ax.com...
> dhou...@fuse.net (Dave Houston) wrote
>> IR does not pass through glass.
>> David Petrone <dav...@advacon.com> wrote
>>> And a convex mirror would probably make the placement less critical.
> Yup, D. Houston is right.
Fraid not.
> A mirror won't work.
Odd, it does for me.
> D. Petrone is not correct.
Fraid so.
Greg Letiecq
> G. Morgan <wacog...@yahoo.com> wrote in message
> news:k7nt5v410f82a889i...@4ax.com...
>
>>dhou...@fuse.net (Dave Houston) wrote
>
>
>>>IR does not pass through glass.
>>
>
This is essentially true, but in the real world we need some caveats.
While IR wil not pass through standard spec window glass, it will
reflect off the surface of with a little degradation of signal. It'll
reflect off other surfaces (high-gloss wall paint, metal, glossy
printing, etc.) as well. While it would be vastly better for
transmission that it pass through a piece of glass and bounce off the
excellent reflective plate of a mirror and back through the glass, we
can see a low-quality (for our purposes) reflection off the surface of
the glass. It's not the mirror that reflects, it's the surface of the
glass. And of course not all "angles of attack" perform equally well,
Go straight on at the glass and you get nearly nothing back. Hit it at
a strongly oblique angle, and the reflection is darned near perfect.
And with the seemingly inconsistent manufacturing specs of modern glass
making, sometiumes you can even pass an IR signal through it. Not well,
but you can often get one through. If it's not glass but acrylic, well,
you get a far better performance there.
Is it a good idea to depend on an IR signal that uses glass as a
transmission medium? Absolutely not. Can you make it work? Sometimes.
I'd rather put something in place that doesn;t depend on the
exceptions, but follows the rules, and for this a receiver/transmitter
is probably a reliable and effective alternative.
Greg
B Fuhrmann
That should be SOME FREQUENCIES of IR do not pass through glass.
What are camera lenses made of? Glass
What range of light do the "night shot" cameras use to videotape in the
dark? IR
Can the flashing IR from a remote control be recorded through many layers of
glass in a camera lens? ABSOLUTLY
MFH...@nothydrologistnot.com
wrote in message <3E5EFA59...@nowhere.org>:
For what it's worth, trying to ascribe particular IR transmission
properties to "glass" is not particularly useful. "Glass" refers to the
lack of crystalline structure and not to composition per se. The IR
transmission properties of glasses depends on their composition and
structure.
Common window glass is not very transmissive but is made primarily of
silica. Fused silica itself is an excellent transmitter of IR, which is
part of why it is used in making halogen lamps. IR-absorptive
(~non-transmissive) material would heat up and melt.
Elsewhere in this thread there are references to IR photography.
A quick flip through the transmittance curves of 40 or so common ("glass",
not "gel") Wratten photographic filters show that the majority have better
than 50% transmittance in the range of 770-900 nanometers ("IR") as do most
all photographic lenses. Remember setting leaves on fire with a magnifying
glass in the sun? One can do that because most optical lenses transmit IR.
Front-surface (aka "first-surface") mirrors available in which the light
does not pass through glass first. Large, new pieces are very expensive,
but there are many sources of inexpensive smaller pieces.
EG: http://www.anchoroptical.com/Products/Display.cfm?catid=257
They are typically made from polished aluminum with a thin silicon dioxide
coating to protect the mirror surface. They may also be coated to partially
absorb IR or not (i.e, to reflect IR =~ "heat transmitting"). So one
cannot generalize about whether mirrors transmit or absorb IR either even
if there is no glass in front of the reflective surface. The IR properties
depend on the manufacturer's intention.
The upshot, however, is that there *are* commercial mirrors that are
excellent transmitters/reflecters of 770-900 nanometer ("IR") light but one
would need to either have the mirror's specs or conduct a simple experiment
to know whether a particular mirror is has useful IR reflectance.
HTH ... Marc
MFH...@nothydrologistnot.com
MFH...@nothydrologistnot.com
message <m01v5v82r5dk4u0q9...@4ax.com>:
I should add that household aluminum foil has no coating at all on either
the shiny or dull side and does reflect IR well. (Remember those reflector
ovens at camp? ) A six-foot piece of foil permanently taped to the hallway
wall wouldn't pass muster in most households, but would be useful as a test
or proof of principle.
... Marc
MFH...@nothydrologistnot.com
Rod Speed
>>>> IR does not pass through glass.
> This is essentially true,
Not with the IR used by the remotes being discussed it aint.
> but in the real world we need some caveats.
Or you could try getting the basics right instead.
> While IR wil not pass through standard spec window glass,
Corse it does with the IR used by the remotes being discussed.
Completely trivial to prove too by using the remote outside thru
a window to the device you usually use the remote on.
> it will reflect off the surface of with a little degradation of signal.
Yep. And when that surface is glass, the degradation wont be great.
That is in fact an approach used with far IR,
using mirrors and gratings instead of lenses etc.
> It'll reflect off other surfaces (high-gloss wall paint, metal,
> glossy printing, etc.) as well. While it would be vastly better for
> transmission that it pass through a piece of glass and bounce off the
> excellent reflective plate of a mirror and back through the glass, we
> can see a low-quality (for our purposes) reflection off the surface of
> the glass. It's not the mirror that reflects, it's the surface of the glass.
Yep.
> And of course not all "angles of attack"
It aint an "angle of attack"
> perform equally well, Go straight on at the glass and
> you get nearly nothing back. Hit it at a strongly oblique
> angle, and the reflection is darned near perfect.
Yep. And the glass transmits the IR used by remotes fine
too, so you'll still get reflection off the mirror back as well.
> And with the seemingly inconsistent manufacturing specs of modern
> glass making, sometiumes you can even pass an IR signal through it.
Not just sometimes, always with the IR used by remotes.
> Not well,
Bullshit.
> but you can often get one through. If it's not glass but
> acrylic, well, you get a far better performance there.
Thats just plain wrong with the IR used by remotes too.
> Is it a good idea to depend on an IR signal that uses
> glass as a transmission medium? Absolutely not.
Bullshit with remotes. Works fine.
> Can you make it work? Sometimes.
Always in fact.
> I'd rather put something in place that doesn;t
> depend on the exceptions, but follows the rules,
Thats the case with glass and IR used by remotes, it always works.
> and for this a receiver/transmitter is probably
> a reliable and effective alternative.
And a mirror is completely reliable and much cheaper.
Rod Speed
<MFH...@nothydrologistnot.com> wrote in message news:m01v5v82r5dk4u0q9...@4ax.com...
Mostly just the composition with the IR transmission being discussed.
> Common window glass is not very transmissive but is made
> primarily of silica. Fused silica itself is an excellent transmitter
> of IR, which is part of why it is used in making halogen lamps.
The real reason its used for halogen lamps is the temperature
they run at. That temperature is necessary for the halide process.
The fact that its IR transparent is irrelevant to its use there.
> IR-absorptive (~non-transmissive) material would heat up and melt.
A minor effect with a bulb thats deliberately run at
very high temps required by the halide process.
> Elsewhere in this thread there are references to IR photography.
> A quick flip through the transmittance curves of 40 or so common ("glass",
> not "gel") Wratten photographic filters show that the majority have better
> than 50% transmittance in the range of 770-900 nanometers ("IR") as do most
> all photographic lenses. Remember setting leaves on fire with a magnifying
> glass in the sun? One can do that because most optical lenses transmit IR.
Thats just concentrating the light, nothing to do with IR.
And a greenhouse works because it lets light
in but isnt as transparent to radiant heat, IR.
Richard Cochran
> "Dave Houston" <dhou...@fuse.net> wrote in message
> news:3e5ed612...@nntp.fuse.net...
> > IR does not pass through glass.
>
> That should be SOME FREQUENCIES of IR do not pass through glass.
Actually, perhaps it should be that SOME FREQUENCIES of IR do not
pass through SOME TYPES of glass. "IR" covers a broad range
of frequencies, and "GLASS" covers a broad range of materials,
so it's dangerous to over-generalize.
> Can the flashing IR from a remote control be recorded through many layers of
> glass in a camera lens? ABSOLUTLY
Actually, you don't need anything fancier than a video camera to prove
this to yourself. Aim any consumer video camera at a TV remote,
and push the buttons on the remote. You'll see that the remote lights
up, as viewed by the camcorder with its glass lens. That's because
the CCD is somewhat sensitive to IR. You'll also see that the IR
signal from the TV remote can be reflected by a mirror, can pass
through a window, etc.
There are plenty of other ways to prove the same thing. I can turn on
my van's stereo or adjust the volume by using the stereo's IR remote
control from outside the vehicle and aiming it through the glass
window. I can control my home stereo via its IR remote control
even when the glass doors of my stereo cabinet are closed.
--Rich
MFH...@nothydrologistnot.com
in message <b3oilh$1nhadt$1...@ID-69072.news.dfncis.de>:
><MFH...@nothydrologistnot.com> wrote in message
news:m01v5v82r5dk4u0q9...@4ax.com...
>>
>> For what it's worth, trying to ascribe particular IR transmission
>> properties to "glass" is not particularly useful. "Glass" refers to the
>> lack of crystalline structure and not to composition per se. The IR
>> transmission properties of glasses depends on their composition and
>> structure.
>
>Mostly just the composition with the IR transmission being discussed.
In fact, the comparison in my next sentence is between two substances made
from the same elements but with different structure. True glasses, including
silicon dioxide window glass, are by definition amorphous. Fused silica is
also silicon dioxide, and is highly cross-linked, but not crystalline.
>> Common window glass is not very transmissive but is made
>> primarily of silica. Fused silica itself is an excellent transmitter
>> of IR, which is part of why it is used in making halogen lamps.
>The real reason its used for halogen lamps is the temperature
>they run at. That temperature is necessary for the halide process.
>The fact that its IR transparent is irrelevant to its use there.
There is of course only a single "real" reason for folks that don't know
that there are in fact several reasons, including the one I stated. which
is:
" IR-absorptive (~non-transmissive) material would heat up and melt."
and that's true whether or not you, Rod Speed, are ignorant of the fact. If
the glass doesn't transmit IR, it absorbs it and its temperature rises.
Absorbing heat (by not transmitting IR) is the function of the
heat-absorbing glass in a photographic enlarger or projector without which
film would melt.
>A minor effect with a bulb thats deliberately run at
>very high temps required by the halide process.
You obviously don't know what you are writing about, but then you probably
have not done as much X-ray diffraction work as I have. The "minor effect"
is what makes possible the household halogen lamp with which you are
familiar.
>> Elsewhere in this thread there are references to IR photography.
>> A quick flip through the transmittance curves of 40 or so common
>> ("glass", not "gel") Wratten photographic filters show that
>> the majority have better than 50% transmittance in the range of 770-900
>> nanometers ("IR") as do most all photographic lenses. Remember setting >>
>> leaves on fire with a magnifying glass in the sun? One can do that
>> because most optical lenses transmit IR.
>
>Thats just concentrating the light, nothing to do with IR.
Huh? The glass in the magnifying glass transmits the IR that causes the
heating, doesn't it? That was the point (that you missed).
>And a greenhouse works because it lets light
>in but isnt as transparent to radiant heat, IR.
What do you think IR radiation is if it isn't light?
You've confused long-wave IR radiation with the near-visible IR.
This is a waste of time ... Marc
MFH...@nothydrologistnot.com
Robert L. Bass
my family room. It also passes through water. The reason I know this is I
can place the remove from my satellite dish against the glass and my
fighting fish ignores it. But when I hold down the volume up or down keys
he comes right over to investigate it.
This leads to another interesting (and useless) factoid. Fighting fish can
see IR.
As to the whole issue at hand, there's some truth in what almost everyone
has said. Yes, some glass non-transmissive in the IR range. No, not all
glass is so. Regardless, IR can and does reflect off some glass surfaces.
How well it reflects is a factor or the wavelength of the IR, the type of
glass, the nature of the surface (this effects dispersal more than
reflectivity) and how clean it happens to be.
A number of posts mentioned camera lenses. Camera lenses I've used for CCTV
over the years pass IR very nicely. Most of these are glass lenses. A few
were plastic or had plastic coatings.
Marc Hult's comments were, as usual, correct to a T. One of the nice things
about this forum is there are several engineers who hang out and share with
the rest of us. I'm not an engineer but I've got enough field experience to
understand how it works and (hopefully) what is the problem when it doesn't.
:^)
Regards,
Robert L Bass
=============================>
Bass Home Electronics
ASA Approved Vendor
http://www.Bass-Home.com
2291 Pine View Cir
Sarasota, FL 34231
877-722-8900 Sales & Support
941-925-9747 Fax
rober...@comcast.net
=============================>
Rod Speed
<MFH...@nothydrologistnot.com> wrote in message
news:4e106vs47mtk9us41...@4ax.com...
> Rod Speed <rod_...@yahoo.com> wrote
>> <MFH...@nothydrologistnot.com> wrote
>>> For what it's worth, trying to ascribe particular IR transmission
>>> properties to "glass" is not particularly useful. "Glass" refers to
>>> the lack of crystalline structure and not to composition per se.
>>> The IR transmission properties of glasses depends on their
>>> composition and structure.
>> Mostly just the composition with the IR transmission being discussed.
> In fact, the comparison in my next sentence is between two substances
> made from the same elements but with different structure.
Fraid not when comparing window glass and
the quartz envelope seen with halide bulbs.
> True glasses, including silicon dioxide window glass,
> are by definition amorphous. Fused silica is also silicon
> dioxide, and is highly cross-linked, but not crystalline.
Yes, but thats not relevant to what is being discussed, IR transparency.
>>> Common window glass is not very transmissive but is made
>>> primarily of silica. Fused silica itself is an excellent transmitter
>>> of IR, which is part of why it is used in making halogen lamps.
>> The real reason its used for halogen lamps is the temperature
>> they run at. That temperature is necessary for the halide process.
>> The fact that its IR transparent is irrelevant to its use there.
> There is of course only a single "real" reason for
> folks that don't know that there are in fact several
> reasons, including the one I stated. which is:
> " IR-absorptive (~non-transmissive) material would heat up and melt."
Fraid not. Quartz is used for the high temperature needed for the
halide process. Thats also the reason you cant dim halide bulbs
reliably because dimming them sees the envelope temperature drop
and that stops the halide process thats crucial for a decent life.
> and that's true whether or not you, Rod Speed, are ignorant of the fact.
> If the glass doesn't transmit IR, it absorbs it and its temperature rises.
And that isnt the reason a quartz envelope is used for halide bulbs.
> Absorbing heat (by not transmitting IR) is the function
> of the heat-absorbing glass in a photographic enlarger
> or projector without which film would melt.
Yes, but that isnt the reason a quartz envelope is used for halide
bulbs. Quartz is used because of the very high temperature the
envelope runs at, essential for the halide process.
>> A minor effect with a bulb thats deliberately run at
>> very high temps required by the halide process.
> You obviously don't know what you are writing about,
We'll see. Check what the halide process involves some time.
http://home.howstuffworks.com//question151.htm
> but then you probably have not done as
> much X-ray diffraction work as I have.
Dangerous business guessing like that in usenet.
> The "minor effect" is what makes possible the
> household halogen lamp with which you are familiar.
Pity it aint why a quartz envelope is used.
>>> Elsewhere in this thread there are references to IR photography.
>>> A quick flip through the transmittance curves of 40 or so common
>>> ("glass", not "gel") Wratten photographic filters show that
>>> the majority have better than 50% transmittance in the range of 770-900
>>> nanometers ("IR") as do most all photographic lenses. Remember setting >>
>>> leaves on fire with a magnifying glass in the sun? One can do that
>>> because most optical lenses transmit IR.
>> Thats just concentrating the light, nothing to do with IR.
> Huh? The glass in the magnifying glass transmits
> the IR that causes the heating, doesn't it?
Nope, the bulk of what arrives at the focuses spot isnt IR energy.
> That was the point (that you missed).
Wrong again.
>> And a greenhouse works because it lets light
>> in but isnt as transparent to radiant heat, IR.
> What do you think IR radiation is if it isn't light?
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
> You've confused long-wave IR radiation with the near-visible IR.
Like hell I am. Radiant energy is NOT
light in the normal use of those terms.
> This is a waste of time ...
Yep, you clearly aint gotta clue about how the halide system works.
Rod Speed
"Robert L. Bass" <rober...@comcast.net> wrote in message news:dEudnW_FTMg...@giganews.com...
> Curiously, IR apparently also passes through the glass in a crystal vase in
> my family room. It also passes through water. The reason I know this is I
> can place the remove from my satellite dish against the glass and my
> fighting fish ignores it. But when I hold down the volume up or down keys
> he comes right over to investigate it.
>
> This leads to another interesting (and useless) factoid. Fighting fish can
> see IR.
>
> As to the whole issue at hand, there's some truth in what almost everyone
> has said. Yes, some glass non-transmissive in the IR range. No, not all
> glass is so. Regardless, IR can and does reflect off some glass surfaces.
> How well it reflects is a factor or the wavelength of the IR, the type of
> glass, the nature of the surface (this effects dispersal more than
> reflectivity) and how clean it happens to be.
>
> A number of posts mentioned camera lenses. Camera lenses I've used for CCTV
> over the years pass IR very nicely. Most of these are glass lenses. A few
> were plastic or had plastic coatings.
> Marc Hult's comments were, as usual, correct to a T.
Fraid not, he hasnt got a clue about the halide process.
Rod Speed
> my family room. It also passes through water. The reason I know this is I
> can place the remove from my satellite dish against the glass and my
> fighting fish ignores it. But when I hold down the volume up or down keys
> he comes right over to investigate it.
>
> This leads to another interesting (and useless) factoid. Fighting fish can
> see IR.
>
> As to the whole issue at hand, there's some truth in what almost everyone
> has said. Yes, some glass non-transmissive in the IR range. No, not all
> glass is so. Regardless, IR can and does reflect off some glass surfaces.
> How well it reflects is a factor or the wavelength of the IR, the type of
> glass, the nature of the surface (this effects dispersal more than
> reflectivity) and how clean it happens to be.
>
> A number of posts mentioned camera lenses. Camera lenses I've used for CCTV
> over the years pass IR very nicely. Most of these are glass lenses. A few
> were plastic or had plastic coatings.
> Marc Hult's comments were, as usual, correct to a T.
Fraid not, he hasnt got a clue about the halide process.
Or why sunlight focused thru a magnifying glass causes
the paper its focussed on to catch fire either.
Robert L. Bass
>
> Fraid not, he hasnt got a clue about the halide process.
I'm not getting into a pissing contest over this. I'm also disinclined to
try to prove it to you. Believe what you like.
Robert L. Bass
>
> Fraid not, he hasnt got a clue about the halide process.
>
> Or why sunlight focused thru a magnifying glass causes
> the paper its focussed on to catch fire either.
"Remember setting leaves on fire with amagnifying glass in the sun? One can dothat because most optical lenses transmitIR."
Rod Speed
> Rod Speed rod_...@yahoo.com
>> Robert L. Bass <rober...@comcast.net> wrote
>>> Marc Hult's comments were, as usual, correct to a T.
>> Fraid not, he hasnt got a clue about the halide process.
> I'm not getting into a pissing contest over this.
Taint a pissing contest, its just basic engineering facts.
In spades with the question of glass transparency
with IR remotes. Trivially provable too.
> I'm also disinclined to try to prove it to you.
You cant with either of those.
> Believe what you like.
It aint about belief, its about proof of claims. Trivial with the
transparency of glass with IR remotes. Just try it thru a window.
Rod Speed
> Rod Speed rod_...@yahoo.com wrote
>> Robert L. Bass <rober...@comcast.net> wrote
>>> Marc Hult's comments were, as usual, correct to a T.
>> Fraid not, he hasnt got a clue about the halide process.
>> Or why sunlight focused thru a magnifying glass
>> causes the paper its focussed on to catch fire either.
> Hmm. I wasn't going to comment further on this but what the heck...
Yep, technical groups are about engineering basics.
> Halide light elements give off extremely intense heat (IR).
Yes, but that is not the reason that a quartz envelope
is used. Its essential for the halide process to work.
> Glass, like anything else the heat strikes, can do one
> of three things with the heat. It can reflect, transmit
> or absorb the energy. In fact, it does a bit of all three.
> Some heat is reflected off the glass. Some is absorbed.
Sure, but thats completely irrelevant to why a quartz envelope
is used with halides. The halide process REQUIRES those very
high temperatures for the halide process to work. That why you
shouldnt dim halides, because they then wont get hot enough.
The quartz envelope is used because normal
glass wont survive those temperatures.
Hasnt got anything to do with IR transparency as Marc claimed.
> That's why if you touch a lit halide bulb
> you'll have a very unpleasant experience.
Just because the halide process only works at very high temperatures.
> The rest (most) of the IR energy is transmitted. If it was
> not the small bulb would quickly heat up and melt or rupture.
Thats completely mangled all over again. The halide process
REQUIRES a very high temperature to work and a quartz
envelope is used because normal glass would not survive.
> Following is Marc's comment regarding a magnifying glass:
> "Remember setting leaves on fire with a
> magnifying glass in the sun? One can do
> that because most optical lenses transmit IR."
> That statement is entirely correct.
Nope, the reason the paper catches fire is because
the entire solar spectrum is focused on that small spot.
You can prove its not just the IR that sets fire to
the paper by using a plastic lense that isnt very
IR transparent. It will still set fire to the paper.
Its the total joules arriving at the spot that matters.
> If the magnifying glass did not pass IR the leaves would not ignite.
Fraid so. And trivial provable by using a plastic lense.
> Concentrated heat (IR) which has passed
> through the magnifying glass does the trick.
Nope, its the total joules that sets fire to the paper.
MFH...@nothydrologistnot.com
in message <b3p92q$1nos93$1...@ID-69072.news.dfncis.de>:
>
><MFH...@nothydrologistnot.com> wrote in message
>news:4e106vs47mtk9us41...@4ax.com...
>> Rod Speed <rod_...@yahoo.com> wrote
>>> <MFH...@nothydrologistnot.com> wrote
>
>>>> For what it's worth, trying to ascribe particular IR transmission
>>>> properties to "glass" is not particularly useful. "Glass" refers to
>>>> the lack of crystalline structure and not to composition per se.
>>>> The IR transmission properties of glasses depends on their
>>>> composition and structure.
>
>>> Mostly just the composition with the IR transmission being discussed.
>
>> In fact, the comparison in my next sentence is between two substances
>> made from the same elements but with different structure.
>
>Fraid not when comparing window glass and
>the quartz envelope seen with halide bulbs.
>
>> True glasses, including silicon dioxide window glass,
>> are by definition amorphous. Fused silica is also silicon
>> dioxide, and is highly cross-linked, but not crystalline.
>
>Yes, but thats not relevant to what is being discussed, IR transparency.
Of course it is. You type these flippant categorical statements as if they
have meaning. What I was discussing was the difference in structure and the
fact that the difference in structure between two substances consisting in
SiO2 causes a difference in physical properties. And fused silica has higher
IR transparency than than typical Si02 "glass" whether you know it or not.
>>>> Common window glass is not very transmissive but is made
>>>> primarily of silica. Fused silica itself is an excellent transmitter
>>>> of IR, which is part of why it is used in making halogen lamps.
>
>>> The real reason its used for halogen lamps is the temperature
>>> they run at. That temperature is necessary for the halide process.
>>> The fact that its IR transparent is irrelevant to its use there.
>
>> There is of course only a single "real" reason for
>> folks that don't know that there are in fact several
>> reasons, including the one I stated. which is:
>
>> " IR-absorptive (~non-transmissive) material would heat up and melt."
>
>Fraid not. Quartz is used for the high temperature needed for the
>halide process. Thats also the reason you cant dim halide bulbs
>reliably because dimming them sees the envelope temperature drop
>and that stops the halide process thats crucial for a decent life.
uh, no. Quartz-halogen is a misnomer. I know my stishovite from my
crystobalite and that what is used in contemporary halogen lanps is
artificially manufactured fused silica, not quartz. Quartz *is* cystalline
by definition and fundamentally different from fused silica.
And yes, the low coefficient of expansion and high melting point are part of
why fused silca is used for the envelope. You write so poorly that it is
next to impossible to figure out what you mean. What does "That's" refer to?
>
>> and that's true whether or not you, Rod Speed, are ignorant of the fact.
>> If the glass doesn't transmit IR, it absorbs it and its temperature
rises.
>
>And that isnt the reason a quartz envelope is used for halide bulbs.
And I never said it was the only reason. Read what I wrote so that you
babble less.
>
>> Absorbing heat (by not transmitting IR) is the function
>> of the heat-absorbing glass in a photographic enlarger
>> or projector without which film would melt.
>
>Yes, but that isnt the reason a quartz envelope is used for halide
>bulbs. Quartz is used because of the very high temperature the
>envelope runs at, essential for the halide process.
You are repeating yourself yet again.
>>> A minor effect with a bulb thats deliberately run at
>>> very high temps required by the halide process.
>
>> You obviously don't know what you are writing about,
>
>We'll see. Check what the halide process involves some time.
>http://home.howstuffworks.com//question151.htm
I think that if you do a dejanews search you find that I explained this in
detail 7-8 years ago or so ago in rec.photo.darkroom, What is your point,
other than to repeat yourself about something that is not contested?
>> but then you probably have not done as
>> much X-ray diffraction work as I have.
>
>Dangerous business guessing like that in usenet.
I'll guess that you haven't done any at all and you are just popping off yet
again. There not much at all dangerous in usenet in my experience.
>> The "minor effect" is what makes possible the
>> household halogen lamp with which you are familiar.
>
>Pity it aint why a quartz envelope is used.
What's more a pity is that quartz hasn't been used for a long time for this
purpose. I know full well why a refractory, thermally stable substance is
used, but that seems to be *all* that you know.
>>>> Elsewhere in this thread there are references to IR photography.
>>>> A quick flip through the transmittance curves of 40 or so common
>>>> ("glass", not "gel") Wratten photographic filters show that
>>>> the majority have better than 50% transmittance in the range of 770-900
>>>> nanometers ("IR") as do most all photographic lenses. Remember setting
>>
>>>> leaves on fire with a magnifying glass in the sun? One can do that
>>>> because most optical lenses transmit IR.
>
>>> Thats just concentrating the light, nothing to do with IR.
>
>> Huh? The glass in the magnifying glass transmits
>> the IR that causes the heating, doesn't it?
>
>Nope, the bulk of what arrives at the focuses spot isnt IR energy.
The "bulk"? You measuring light in bushel baskets?. "of what" -- right --
"of what" do you write?
You write/think so sloppily that it is not worth continuing. The energy
distribution in daylight depends crucially on the angle of the sun, amount
of moisture in the air. among other factors. You will find (should you care
to try it) that if you filter out the IR that the magnifying trick will not
work nearly so well. But obviously it isn't all the incident light energy at
the earth's surface and by definition, one could use larger magnifying glass
to make up for the loss energy.
>
>> That was the point (that you missed).
>
>Wrong again.
>
>>> And a greenhouse works because it lets light
>>> in but isnt as transparent to radiant heat, IR.
>
>> What do you think IR radiation is if it isn't light?
>
>Even you should be able to bullshit your way out of
>your predicament better than that pathetic effort.
I don't b******* . You can't even use the right words, so its hard to know
whether there's more to what you are trying to say than than the scatology
that makes it to the computer screen, but its clear that it is pointless to
discuss this with you any further
>> You've confused long-wave IR radiation with the near-visible IR.
>
>Like hell I am. Radiant energy is NOT
>light in the normal use of those terms.
You are babbling.
>> This is a waste of time ...
>
>Yep, you clearly aint gotta clue about how the halide system works.
Yes I do, but that's not the point.
Perhaps you will come back when you aren't impaired and write in meaningful
sentences about topics that have relevance to HA.
Bye ... Marc
MFH...@nothydrologistnot.com
MFH...@nothydrologistnot.com
in message <b3p9fa$1oer26$1...@ID-69072.news.dfncis.de>:
What Rod Speed so tediously eems to point out that he knows - without
actually managing to state it -- is the fact the tungsten filaments in
lamps sublimate when heated and that the high temperature of the fused
silica inner lamp in a halogen lamp in combination with the (eg) iodine
vapor reduces condensation of the tungsten on it -- unlike a conventional
tungstern lamps which we've all seen turn black from the deposits derived
from the filament.
There! Now that's done. But the facts remain that fused silica has the same
chemical composition as other Si02 glasses, but has different properties --
including excellent IR transmission by virtue of its structure. He (like
many other folks) confuses quartz with fused silica, and I think he's trying
to claim that I think that high percent IR transmission is the only reason
that a refractory "glass" is used for this purpose which is as ludicrous as
he is. In particular, the low coefficient of thermal expansion and the high
melting point are also critical factors.
As to his remark that I don't know "why sunlight focused thru a magnifying
glass causes the paper its [sic] focussed on to catch fire either", this
shows to me that he really has no intention of reading or understanding or
being helpful -- which the point of this newsgroup.
... Marc
David Petrone
1. A mirror does not imply glass
2. A glass front surface mirror would not require passing through glass for
the desired reflection.
3. There are about 3 things that can happen when light strikes a substance:
a. It can be transmitted
b. It can be absorbed
c. It can be reflected.
Both a and c above should work for the purpose inquired about.
In any event I will amend my statement:
And a convex IR reflecting surface would probably make the placement less
critical because it is reflect the beam over a larger area, as long as it
retains enough signal strength to be significant to the receiver.
Let the IR theory/practice wars begin anew!
Dave
"Dave Houston" <dhou...@fuse.net> wrote in message
news:3e5ed612...@nntp.fuse.net...
MFH...@nothydrologistnot.com
<rober...@comcast.net> wrote in message
<mvWdnehflbt...@giganews.com>:
>>> Marc Hult's comments were, as usual, correct to a T.
>>
>> Fraid not, he hasnt got a clue about the halide process.
>>
>> Or why sunlight focused thru a magnifying glass causes
>> the paper its focussed on to catch fire either.
>
>Hmm. I wasn't going to comment further on this but what the heck...
Let it go Robert.
I wrote "Fused silica itself is an excellent transmitter
of IR, which is part of why it is used in making halogen lamps." .
Apparently he has chosen not to acknowledge the word "partially" . He's
probably a rational guy when not all inflamed.
The topic of halogen lamps was one that I delved into in considerable detail
several years ago. The pressure/heat/vapor concentration relationships in
halogen lamps has been studied extensively. An important part of the heat
budget depends on the IR absorbance of the inner bulb enclosure. That's what
I was referring to. If the envelope absorbs more IR, it needs to be further
away from the filament to stay at the optimum temperature which in turn
requires more halogen to keep the same internal pressure and a larger
diameter bulb which becomes weaker and more likely to shatter for the same
thickness. The need for a double lamp is a cost factor in designing halogen
lamps, and the smaller the total size, the less the cost. It is a design
trade off. Rod knows something about part of this and thinks he knows it
all. C'est tout.
HTH ... Marc
MFH...@nothydrologistnot.com
Rod Speed
<MFH...@nothydrologistnot.com> wrote in message
news:dcj06vo6hhi0b1ona...@4ax.com...
> Rod Speed <rod_...@yahoo.com> wrote
>> <MFH...@nothydrologistnot.com> wrote
>>> Rod Speed <rod_...@yahoo.com> wrote
>>>> <MFH...@nothydrologistnot.com> wrote
>>>>> For what it's worth, trying to ascribe particular IR transmission
>>>>> properties to "glass" is not particularly useful. "Glass" refers to
>>>>> the lack of crystalline structure and not to composition per se.
>>>>> The IR transmission properties of glasses depends on their
>>>>> composition and structure.
>>>> Mostly just the composition with the IR transmission being discussed.
>>> In fact, the comparison in my next sentence is between two substances
>>> made from the same elements but with different structure.
>> Fraid not when comparing window glass and
>> the quartz envelope seen with halide bulbs.
>>> True glasses, including silicon dioxide window glass,
>>> are by definition amorphous. Fused silica is also silicon
>>> dioxide, and is highly cross-linked, but not crystalline.
>> Yes, but thats not relevant to what is being discussed, IR transparency.
> Of course it is.
Nope, particularly with transparency to the IR wavelengths
used with IR remotes. There is no practical difference in the
IR transparency with those two glasses and the undoubted
difference structures is completely irrelevant to what was being
discussed, transparency to the IR wavelengths used by IR remotes.
> You type these flippant categorical statements as if they have meaning.
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
> What I was discussing was the difference in structure and the
> fact that the difference in structure between two substances
> consisting in SiO2 causes a difference in physical properties.
Nope, particularly with transparency to the IR wavelengths
used with IR remotes. There is no practical difference in the IR
transparency with those two glasses and the undoubted difference
structures is completely irrelevant to what was being discussed,
transparency to the IR wavelengths used by IR remotes.
> And fused silica has higher IR transparency than than typical Si02 "glass"
Fraid not with the IR wavelengths used by IR remotes.
> whether you know it or not.
Keep digging.
>>>>> Common window glass is not very transmissive but is made
>>>>> primarily of silica. Fused silica itself is an excellent transmitter
>>>>> of IR, which is part of why it is used in making halogen lamps.
>>>> The real reason its used for halogen lamps is the temperature
>>>> they run at. That temperature is necessary for the halide process.
>>>> The fact that its IR transparent is irrelevant to its use there.
>>> There is of course only a single "real" reason for
>>> folks that don't know that there are in fact several
>>> reasons, including the one I stated. which is:
>>> " IR-absorptive (~non-transmissive) material would heat up and melt."
>> Fraid not. Quartz is used for the high temperature needed for the
>> halide process. Thats also the reason you cant dim halide bulbs
>> reliably because dimming them sees the envelope temperature drop
>> and that stops the halide process thats crucial for a decent life.
> uh, no.
Fraid so.
> Quartz-halogen is a misnomer.
Just another example of general terminology being less
specific than whats used scientifically. In precisely the same
way that the radiation from a greenhouse at night is technically
light of IR wavelengths, but that is not how the word light is usually
used. In general used it just means light of visible wavelengths.
As you know damned well.
> I know my stishovite from my crystobalite and that what
> is used in contemporary halogen lanps is artificially
> manufactured fused silica, not quartz. Quartz *is* cystalline
> by definition and fundamentally different from fused silica.
There is no practical difference in the IR transparency with
'fused silica' and normal glass used in windows and the undoubted
difference structures is completely irrelevant to what was being
discussed, transparency to the IR wavelengths used by IR remotes.
> And yes, the low coefficient of expansion and high melting
> point are part of why fused silca is used for the envelope.
In fact the reason its used has nothing to do
with IR transparency as you initially claimed.
Its JUST about using what will survive the very high
temperatures that the halide process requires to work.
> You write so poorly that it is next to impossible to figure
> out what you mean. What does "That's" refer to?
Its a contraction of 'that is' as you know damned well. Its obviously
referrring to the reason halides arent suitable for dimming.
> >> and that's true whether or not you, Rod Speed, are ignorant of the fact.
> >> If the glass doesn't transmit IR, it absorbs it and its temperature rises.
>> And that isnt the reason a quartz envelope is used for halide bulbs.
> And I never said it was the only reason.
I never said you did. Hasnt got a damned thing to do with the IR
transparency as you originally claimed. Its all about an envelope that will
survive the very high temperatures that the halide process requires to work.
> Read what I wrote so that you babble less.
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
>>> Absorbing heat (by not transmitting IR) is the function
>>> of the heat-absorbing glass in a photographic enlarger
>>> or projector without which film would melt.
>> Yes, but that isnt the reason a quartz envelope is used for halide
>> bulbs. Quartz is used because of the very high temperature the
>> envelope runs at, essential for the halide process.
> You are repeating yourself yet again.
Corse you never ever do anything like that yourself, eh ?
>>>> A minor effect with a bulb thats deliberately run at
>>>> very high temps required by the halide process.
>>> You obviously don't know what you are writing about,
>> We'll see. Check what the halide process involves some time.
>> http://home.howstuffworks.com//question151.htm
> I think that if you do a dejanews search you find that I explained
> this in detail 7-8 years ago or so ago in rec.photo.darkroom,
All completely and utterly irrelevant to your stupid claim that
'You obviously don't know what you are writing about'
> What is your point,
You have absolutely no idea at all, eh ? Yeah, right.
> other than to repeat yourself about something that is not contested?
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
>>> but then you probably have not done as
>>> much X-ray diffraction work as I have.
>> Dangerous business guessing like that in usenet.
> I'll guess that you haven't done any at all
Guess who just made a VERY spectacular fool of himself ?
> and you are just popping off yet again. There not
> much at all dangerous in usenet in my experience.
Sure, no real danger of anything worse than making
a VERY spectacular fool of yourself, repeatedly.
Even you should be able to use groups.google
and discover what a spectacular fool you have
just made of yourself with that particular guess.
>>> The "minor effect" is what makes possible the
>>> household halogen lamp with which you are familiar.
>> Pity it aint why a quartz envelope is used.
> What's more a pity is that quartz hasn't been used for a long time
> for this purpose. I know full well why a refractory, thermally stable
> substance is used, but that seems to be *all* that you know.
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
Aint gotta damned thing to do with the IR transparency you initially claimed.
>>>>> Elsewhere in this thread there are references to IR photography.
>>>>> A quick flip through the transmittance curves of 40 or so common
>>>>> ("glass", not "gel") Wratten photographic filters show that
>>>>> the majority have better than 50% transmittance in the range of 770-900
>>>>> nanometers ("IR") as do most all photographic lenses. Remember setting
>>>>> leaves on fire with a magnifying glass in the sun? One can do that
>>>>> because most optical lenses transmit IR.
>>>> Thats just concentrating the light, nothing to do with IR.
>>> Huh? The glass in the magnifying glass transmits
>>> the IR that causes the heating, doesn't it?
>> Nope, the bulk of what arrives at the focuses spot isnt IR energy.
> The "bulk"? You measuring light in bushel baskets?.
> "of what" -- right -- "of what" do you write?
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
> You write/think so sloppily that it is not worth continuing.
But you did anyway.
> The energy distribution in daylight depends crucially on the angle
> of the sun, amount of moisture in the air. among other factors.
Even you should be able to waffle better than that pathetic effort.
> You will find (should you care to try it) that if you filter out
> the IR that the magnifying trick will not work nearly so well.
But it still set fire to the paper/leaves, so
it obviously aint the IR thats doing that.
> But obviously it isn't all the incident light energy at the
> earth's surface and by definition, one could use larger
> magnifying glass to make up for the loss energy.
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
>>> That was the point (that you missed).
>> Wrong again.
>>>> And a greenhouse works because it lets light
>>>> in but isnt as transparent to radiant heat, IR.
>>> What do you think IR radiation is if it isn't light?
>> Even you should be able to bullshit your way out of
>> your predicament better than that pathetic effort.
> I don't b******* .
Everyone can see for themselves that you do.
> You can't even use the right words, so its hard to know
> whether there's more to what you are trying to say than than
> the scatology that makes it to the computer screen, but its
> clear that it is pointless to discuss this with you any further
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
>>> You've confused long-wave IR radiation with the near-visible IR.
>> Like hell I am. Radiant energy is NOT
>> light in the normal use of those terms.
> You are babbling.
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
>>> This is a waste of time ...
>> Yep, you clearly aint gotta clue about how the halide system works.
> Yes I do, but that's not the point.
Fraid so.
> Perhaps you will come back when you aren't impaired and write
> in meaningful sentences about topics that have relevance to HA.
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
> Bye ... Marc
> MFH...@nothydrologistnot.com
Good riddance. Keep bullshitting, you might
actually manage to fool someone, sometime.
Rod Speed
<MFH...@nothydrologistnot.com> wrote in message news:qcj06vsbv610a1bf4...@4ax.com...
Careful you dont go blind now.
> But the facts remain that fused silica has the same chemical
> composition as other Si02 glasses, but has different properties
> -- including excellent IR transmission by virtue of its structure.
Wrong with the IR wavelengths being discussed, whats used by IR remotes.
> He (like many other folks) confuses quartz with fused silica,
Wrong again. Thats just the normal terminology used with those.
> and I think he's trying to claim that I think that high percent
> IR transmission is the only reason that a refractory "glass"
> is used for this purpose which is as ludicrous as he is.
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
> In particular, the low coefficient of thermal expansion
> and the high melting point are also critical factors.
And your original claim about IR transparency aint.
> As to his remark that I don't know "why sunlight focused thru a
> magnifying glass causes the paper its [sic] focussed on to catch
> fire either", this shows to me that he really has no intention of reading
> or understanding or being helpful -- which the point of this newsgroup.
Even you should be able to bullshit your way out of
Rod Speed
<MFH...@nothydrologistnot.com> wrote in message
news:rql06vg480b9prl74...@4ax.com...
> Robert L. Bass <rober...@comcast.net> wrote
>>>> Marc Hult's comments were, as usual, correct to a T.
>>> Fraid not, he hasnt got a clue about the halide process.
>>> Or why sunlight focused thru a magnifying glass causes
>>> the paper its focussed on to catch fire either.
>> Hmm. I wasn't going to comment further on this but what the heck...
> Let it go Robert.
Why doesnt that apply to yourself ? You one of those hypocrites ?
> I wrote "Fused silica itself is an excellent transmitter of IR,
> which is part of why it is used in making halogen lamps." .
Pity it aint 'part of' at all.
> Apparently he has chosen not to acknowledge the word "partially" .
Because it aint 'part of why it is used in making halogen lamps'
> He's probably a rational guy when not all inflamed.
Just another of your pathetic little drug crazed fantasys on 'inflamed'
> The topic of halogen lamps was one that I delved
> into in considerable detail several years ago.
Whoopy do. Pity you never managed to grasp that it aint gotta
damned thing to do with it being 'an excellent transmitter of IR'
> The pressure/heat/vapor concentration relationships in
> halogen lamps has been studied extensively. An important
> part of the heat budget depends on the IR absorbance of
> the inner bulb enclosure. That's what I was referring to.
Waffle.
> If the envelope absorbs more IR, it needs to be further
> away from the filament to stay at the optimum temperature
> which in turn requires more halogen to keep the same
> internal pressure and a larger diameter bulb which becomes
> weaker and more likely to shatter for the same thickness.
All completely and utterly irrelevant to why fused silica is actually used
in the first place. Thats just a detail of HOW its used when its used for
the much more fundamental reason, the temperature those operate at.
> The need for a double lamp is a cost factor in designing halogen lamps,
> and the smaller the total size, the less the cost. It is a design trade off.
More completely irrelevant waffle as far as your original claim
about IR transmission is concerned. There is NO alternative to
the use of fused silica, and the IR transmission is just another
factor in the design of how the fused silica is used.
> Rod knows something about part of this and thinks he knows it all.
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort.
> C'est tout.
Wota posturing wanker.
> HTH ... Marc
> MFH...@nothydrologistnot.com
Robert L. Bass
This one's about home automation. If you want to get into the specifics,
halide lights work by passing a current between two electrodes through a
metal vapor. This sends lots of free floating electrons on a path between
the electrodes. They bang into the metal atoms in the vapor. The process
knocks some electrons out of their normal orbits. In this distrurbed state
the electrons hold potential energy from the electrons that have hit them,
much like a baseall hit straight up into the air holds potential energy
taken from the batter's arm when it reaches the top of it's arc. The ball
releases some of that energy into the air as friction on the way down. The
rest is transmitted into the catcher's glove at the end of the ball's
flight.
As the electrons settle back down into their normal orbits they release
energy in the form of radiation (primarily visible visible light and heat).
Now we've established that both of us (well, at least one of us anyway) know
how HID lights work. Interesting stuff, but it doesn't answer the question
at hand.
>> Halide light elements give off extremely intense heat (IR).
>
> Yes, but that is not the reason that a quartz envelope
> is used. Its essential for the halide process to work.
I didn't say otherwise.
> > Glass, like anything else the heat strikes, can do one
> > of three things with the heat. It can reflect, transmit
> > or absorb the energy. In fact, it does a bit of all three.
> > Some heat is reflected off the glass. Some is absorbed.
>
> Sure, but thats completely irrelevant to why a quartz
> envelope is used with halides...
And that is entirely irrelevant to the fact that different types of glass
are more or less transmissive of various frequencies of IR.
> The halide process REQUIRES those very high
> temperatures for the halide process to work.
True, but if the glass did not pass IR the lamp would quickly overheat and
self-destruct.
> That why you shouldnt dim halides, because
> they then wont get hot enough.
And if they are allowed to get too hot they will fail.
> The quartz envelope is used because normal
> glass wont survive those temperatures.
>
> Hasnt got anything to do with IR transparency as Marc claimed.
If the quartz envelope was non-transmissive to IR, it too would not survive.
>> That's why if you touch a lit halide bulb
>> you'll have a very unpleasant experience.
>
> Just because the halide process only works at very high temperatures.
And? Show how that contradicts anything Marc said.
>> The rest (most) of the IR energy is transmitted. If it was
>> not the small bulb would quickly heat up and melt or rupture.
>
> Thats completely mangled all over again.
Nope. That's many years of experience using these bulbs, friend. If the
fixture around the bulb doesn't release the intense heat in to the
surrounding air, the bulb will fail. That's why the fixtures are invariably
ventilated.
> The halide process REQUIRES a very high temperature
> to work and a quartz envelope is used because normal
> glass would not survive.
Think about what you're saying. There is an acceptable operating
temperature for HID bulbs. Below it they don't work well and have short
lives. Much above it and they self-destruct in a relatively short time. By
way of analogy, my favorite baked salmon recipe calls for an oven
temperature of 500ºF. Salmon won't cook in the alloted time at less than
500 degrees. But try cooking it with the oven set for "self clean" and it
turns to ash. Just because something requires a "high" temperature does not
mean it will work at unlimited temps.
>> Following is Marc's comment regarding a magnifying glass:
>
>> "Remember setting leaves on fire with a
>> magnifying glass in the sun? One can do
>> that because most optical lenses transmit IR."
>
>> That statement is entirely correct.
>
> Nope, the reason the paper catches fire is because
> the entire solar spectrum is focused on that small spot.
Sure. Try this. Set up an array of powerful UV lights. Place a piece of
dry tissue paper below them. Focus the light with a magnifying glass. Hold
your breath. I'll be back later. :^)
Robert L. Bass
> <rober...@comcast.net> wrote in message
> <mvWdnehflbt...@giganews.com>:
>
> >>> Marc Hult's comments were, as usual, correct to a T.
> >>
> >> Fraid not, he hasnt got a clue about the halide process.
> >>
> >> Or why sunlight focused thru a magnifying glass causes
> >> the paper its focussed on to catch fire either.
> >
> >Hmm. I wasn't going to comment further on this but what the heck...
>
> Let it go Robert.
I probably should. :)
> I wrote "Fused silica itself is an excellent transmitter
> of IR, which is part of why it is used in making halogen lamps." .
>
> Apparently he has chosen not to acknowledge the word "partially" . He's
> probably a rational guy when not all inflamed.
Yep. BTW, your name came up in a discussion with several of the folks at
the Expo in Orlando on Friday. Suffice it to say the comments were
complimentary.
> The topic of halogen lamps was one that I delved
> into in considerable detail several years ago. The
> pressure/heat/vapor concentration relationships in
> halogen lamps has been studied extensively. An
> important part of the heat budget depends on the
> IR absorbance of the inner bulb enclosure.
My experience with various types of high intensity bulbs stems from
installing theatrical lighting systems. At any rate, having seen what these
bulbs can do to a nearby combustible surface, I have zero doubt that the
glass passes plenty of IR.
Rod Speed
>> Yep, technical groups are about engineering basics.
> This one's about home automation.
Yep, and was originally about whether the IR wavelengths used by
IR remotes goes thru glass fine. It does, and its trivial to prove that.
> If you want to get into the specifics, halide lights work by passing
> a current between two electrodes through a metal vapor.
Wrong. The halide process with halogens is about preventing
the erosion of the filament. That filament operates the same
way as any incandescent lamp filament does as far as getting
hot when current goes thru it is concerned.
> This sends lots of free floating electrons on a path between the
> electrodes. They bang into the metal atoms in the vapor. The process
> knocks some electrons out of their normal orbits. In this distrurbed state
> the electrons hold potential energy from the electrons that have hit them,
> much like a baseall hit straight up into the air holds potential energy
> taken from the batter's arm when it reaches the top of it's arc. The ball
> releases some of that energy into the air as friction on the way down. The
> rest is transmitted into the catcher's glove at the end of the ball's flight.
> As the electrons settle back down into their normal orbits they release
> energy in the form of radiation (primarily visible visible light and heat).
You're utterly mangling how halogens work
with a completely different technology.
> Now we've established that both of us (well, at least
> one of us anyway) know how HID lights work.
You clearly dont.
> Interesting stuff, but it doesn't answer the question at hand.
There is no 'question at hand' that hasnt been perfectly
adequately covers and thats trivial to prove any time there is any doubt
about whether the IR use with IR remotes works fine thru normal glass.
>>> Halide light elements give off extremely intense heat (IR).
>> Yes, but that is not the reason that a quartz envelope
>> is used. Its essential for the halide process to work.
> I didn't say otherwise.
I didnt say you did.
>>> Glass, like anything else the heat strikes, can do one
>>> of three things with the heat. It can reflect, transmit
>>> or absorb the energy. In fact, it does a bit of all three.
>>> Some heat is reflected off the glass. Some is absorbed.
>> Sure, but thats completely irrelevant to why
>> a quartz envelope is used with halides...
> And that is entirely irrelevant to the fact that different types of
> glass are more or less transmissive of various frequencies of IR.
Duh.
>> The halide process REQUIRES those very high
>> temperatures for the halide process to work.
> True, but if the glass did not pass IR the
> lamp would quickly overheat and self-destruct.
Duh.
>> That why you shouldnt dim halides, because
>> they then wont get hot enough.
> And if they are allowed to get too hot they will fail.
Duh.
>> The quartz envelope is used because normal
>> glass wont survive those temperatures.
>> Hasnt got anything to do with IR transparency as Marc claimed.
> If the quartz envelope was non-transmissive to IR, it too would not survive.
Duh. It aint why the quartz envelope is used.
>>> That's why if you touch a lit halide bulb
>>> you'll have a very unpleasant experience.
> > Just because the halide process only works at very high temperatures.
> And? Show how that contradicts anything Marc said.
Never said it did. Thats a comment on what YOU said.
>>> The rest (most) of the IR energy is transmitted. If it was
>>> not the small bulb would quickly heat up and melt or rupture.
>> Thats completely mangled all over again.
> Nope.
Yep.
> That's many years of experience using these bulbs, friend.
Clearly hasnt helped you to grasp how they actually work.
> If the fixture around the bulb doesn't release the intense
> heat in to the surrounding air, the bulb will fail. That's
> why the fixtures are invariably ventilated.
They aint 'invariably ventilated'
And that STILL doesnt have a damned thing to do with what
was being discussed, why a QUARTZ envelope is used.
>> The halide process REQUIRES a very high temperature to work
>> and a quartz envelope is used because normal glass would not survive.
> Think about what you're saying.
Dont need to.
> There is an acceptable operating temperature for HID bulbs.
There is an acceptable operating temperature for ALL bulbs.
And that STILL doesnt have a damned thing to do with what
was being discussed, why a QUARTZ envelope is used.
> Below it they don't work well and have short lives.
Because the halide process doesnt work.
> Much above it and they self-destruct in a relatively short time.
Bullshit.
> By way of analogy, my favorite baked salmon recipe calls
> for an oven temperature of 500ºF. Salmon won't cook in
> the alloted time at less than 500 degrees. But try cooking
> it with the oven set for "self clean" and it turns to ash.
Doesnt have a damned thing to do with how halogens work.
> Just because something requires a "high" temperature
> does not mean it will work at unlimited temps.
No one ever said it will.
>>> Following is Marc's comment regarding a magnifying glass:
>>> "Remember setting leaves on fire with a
>>> magnifying glass in the sun? One can do
>>> that because most optical lenses transmit IR."
>>> That statement is entirely correct.
>> Nope, the reason the paper catches fire is because
>> the entire solar spectrum is focused on that small spot.
> Sure. Try this. Set up an array of powerful UV
> lights. Place a piece of dry tissue paper below
> them. Focus the light with a magnifying glass.
You cant with that light source.
> Hold your breath. I'll be back later. :^)
Try the other MUCH more valid test. Use a plastic lens that doesnt
transmit the IR, still focus the sun. Even you will notice that the
paper/leaves still catch fire. So it cant be the IR thats done that.
You dont actually have a clue about basic physics, do you ?
Rod Speed
> My experience with various types of high intensity bulbs stems
> from installing theatrical lighting systems. At any rate, having
> seen what these bulbs can do to a nearby combustible
> surface, I have zero doubt that the glass passes plenty of IR.
No one ever said they didnt.
What was being discussed was why a quartz envelope is used with halogens.
Even you should be able to put your hand in front of
a conventional incandescent bulb of similar power like
a PAR 38 and notice how hot your hand gets.
Clearly that non quartz envelope is transmitting plenty of IR too.
Dave Houston
neither is 100%. But, with a silica glass mirror, most of the IR will have
to pass through more than twice the thickness of the glass and there will be
more absorption.
Consumer IR uses 940nm. While that's not pertinent to your points I see
where others have incorrectly indicated other wavelengths.
There's at least a 4th thing that can happen - it can be diffused. I think a
convex surface would diffuse and weaken the beam and thus reduce the chance
that it would accomplish its purpose. IR emitters differ in output power and
in beam angle.
It would be better to forget the mirror and just use the backing. I guess
that agrees with your point that a mirror does not imply glass. ;)
"David Petrone" <dav...@advacon.com> wrote:
Robert L. Bass
> > from installing theatrical lighting systems. At any rate, having
> > seen what these bulbs can do to a nearby combustible
> > surface, I have zero doubt that the glass passes plenty of IR.
>
> No one ever said they didnt.
>
> What was being discussed was why a quartz envelope is used with halogens.
Actually, although the term "quartz" is commonly used, most of them are no
longer quartz.
> Even you should be able to put your hand in front of
> a conventional incandescent bulb of similar power like
> a PAR 38 and notice how hot your hand gets.
And???
> Clearly that non quartz envelope is transmitting plenty of IR too.
I never said it doesn't.
BTW, your previous statements about halides were wrong. Take a little time
and read up on the subject. Then get back to us.
--
Robert L. Bass
Typically there is a 50% loss of effective range if a single mirror is added
to the system. Effective range is roughly proportional to the square of the
power. A range reduction of 50% means you've lost about 30% of the
radiation. Wavelength on these is in the neighborhood of 9000Å. Not
exactly close to your TV remote.
> Silica glass absorbs infrared. Alumina glass transmits infrared. Of course
> neither is 100%. But, with a silica glass mirror, most of the IR will have
> to pass through more than twice the thickness of the glass and there will
be
> more absorption.
>
> Consumer IR uses 940nm. While that's not pertinent to your points I see
> where others have incorrectly indicated other wavelengths.
Regards,
MFH...@nothydrologistnot.com
message <3e6096c2....@nntp.fuse.net>:
>---
>http://www.laser.com/dhouston/
Which is why I wrote On Fri, 28 Feb 2003 16:18:34 GMT,
MFH...@nothydrologistnot.com wrote in message
<g92v5vs0q7ompvlql...@4ax.com>:
I [Marc] should add that household aluminum foil has no coating at
all on either the shiny or dull side and does reflect IR well.
(Remember those reflector ovens at camp? ) A six-foot piece of
foil permanently taped to the hallway wall wouldn't pass muster
in most households, but would be useful as a test or proof
of principle."
after pointing out that front-surface (first-surface mirrors) were made from
polished aluminum.
... Marc
MFH...@nothydrologistnot.com
MFH...@nothydrologistnot.com
<rober...@comcast.net> wrote in message
<qPidnTOCLrV...@giganews.com>:
It seems that Rod Speed would still be ranting even if I had written " Fused
silica itself is an excellent transmitter of _visible light_ which is part
of why it is used in making halogen lamps."
The only pertinent property that seems to satisfy his one-track mind is
melting point (or more exactly, softening point). I wonder if he hops on one
leg, uses one hand, thinks with one side of his brain --oops we already
answered that ;-)
Cheers ...Marc
Rod Speed
>>> My experience with various types of high intensity bulbs stems
>>> from installing theatrical lighting systems. At any rate, having
>>> seen what these bulbs can do to a nearby combustible
>>> surface, I have zero doubt that the glass passes plenty of IR.
>> No one ever said they didnt.
>> What was being discussed was why
>> a quartz envelope is used with halogens.
> Actually, although the term "quartz" is commonly
> used, most of them are no longer quartz.
Duh.
What was being discussed was why a
fused silica envelope is used with halogens.
>> Even you should be able to put your hand in front of
>> a conventional incandescent bulb of similar power like
>> a PAR 38 and notice how hot your hand gets.
> And???
Clearly the glass which isnt fused silica with those, is passing the IR.
>> Clearly that non quartz envelope is transmitting plenty of IR too.
> I never said it doesn't.
I never said you did.
> BTW, your previous statements about halides were wrong.
Crap.
> Take a little time and read up on the subject.
No thanks, its you that doesnt have
a clue about the basics with halogens.
> Then get back to us.
How many of you is there between those ears ?
Rod Speed
<MFH...@nothydrologistnot.com> wrote in message
news:b4h16vg0fnr9jvboa...@4ax.com...>> <MFH...@nothydrologistnot.com> wrote
>>> Robert L. Bass <rober...@comcast.net> wrote
>>>>>> Marc Hult's comments were, as usual, correct to a T.
>>>>> Fraid not, he hasnt got a clue about the halide process.
>>>>> Or why sunlight focused thru a magnifying glass causes
>>>>> the paper its focussed on to catch fire either.
>>>> Hmm. I wasn't going to comment further on this but what the heck...
>>> Let it go Robert.
You clearly cant let it go yourself. You one of those hypocrites ?
>> I probably should. :)
>>> I wrote "Fused silica itself is an excellent transmitter
>>> of IR, which is part of why it is used in making halogen lamps." .
>>> Apparently he has chosen not to acknowledge the word "partially" .
>>> He's probably a rational guy when not all inflamed.
>> Yep. BTW, your name came up in a discussion with
>> several of the folks at the Expo in Orlando on Friday.
>> Suffice it to say the comments were complimentary.
>>> The topic of halogen lamps was one that I delved
>>> into in considerable detail several years ago. The
>>> pressure/heat/vapor concentration relationships in
>>> halogen lamps has been studied extensively. An
>>> important part of the heat budget depends on the
>>> IR absorbance of the inner bulb enclosure.
>> My experience with various types of high intensity bulbs stems
>> from installing theatrical lighting systems. At any rate, having
>> seen what these bulbs can do to a nearby combustible surface,
>> I have zero doubt that the glass passes plenty of IR.
> It seems that Rod Speed would still be ranting
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort Hult.
> even if I had written " Fused silica itself is an excellent transmitter of
> _visible light_ which is part of why it is used in making halogen lamps."
Wrong again.
> The only pertinent property that seems to satisfy his one-track
> mind is melting point (or more exactly, softening point).
Its the reason that fused silica is used
and not whats used in other bulbs, stupid.
> I wonder if he hops on one leg, uses one hand, thinks with
> one side of his brain --oops we already answered that ;-)
Even you should be able to bullshit your way out of
your predicament better than that pathetic effort Hult.
Rod Speed
> Silica glass absorbs infrared.
Not the IR used by IR remotes.
> Alumina glass transmits infrared. Of course neither is 100%.
In reality normal glass commonly seen with mirrors
and windows transmits the IR used by IR remotes
fine, and its completely trivial to prove that.
> But, with a silica glass mirror, most of the IR will
> have to pass through more than twice the thickness
> of the glass and there will be more absorption.
And with IR remotes, it will work fine anyway.
> Consumer IR uses 940nm. While that's not pertinent to your points
> I see where others have incorrectly indicated other wavelengths.
> There's at least a 4th thing that can happen - it can be diffused.
> I think a convex surface would diffuse and weaken the beam
> and thus reduce the chance that it would accomplish its purpose.
In practice it works fine.
> IR emitters differ in output power and in beam angle.
Sure, but in practice it works fine.
> It would be better to forget the mirror and just use the backing.
Nope. Because its much easier to find an appropriate mirror and it'll work fine.
MFH...@nothydrologistnot.com
in message <b3pnfu$1nvhgl$1...@ID-69072.news.dfncis.de>:
>There is NO alternative to the use of fused silica, and the IR transmission
>is just another factor in the design of how the fused silica is used.
So Rod Speed is under the misconception that there are no alternatives to
fused silica and quartz for making halogen lamps which -- along with a foul
mouth -- is part of his problem.
I wrote that ""Fused silica itself is an excellent transmitter of IR,
which is part of why it is used in making halogen lamps." which is what has
got Rod so bent out of shape.
Unbeknownst to him, he may already own halogen lamps that use *neither*
fused silica nor quartz, so the assumption at the root of his bluster and
shameful behavior is flat-out, categorically, and demonstrably wrong.
If fused silica and quartz were *not* an "excellent transmitter of IR", and
so heat up excessively for that purpose, there would still be the option of
making halogen lamps out of other substances:
http://www.schott.com/magazine/english/prisma/si102_13e_corning.html
http://www.corning.com/lightingmaterials/products/halogen1.html
Might be interesting if Rod Speed were to direct his foul-mouthed nonsense
at Schott, Corning, and other manufacturers of these other glasses used in
halogen lamps.
In fact, aluminosilicate glasses of various sorts ( which are not quartz or
fused silica) have become commonplace in automotive halogen headlights,
And fused alumina (no silica at all) has been used for decades where
improvement in IR transmission compared to quartz and fused silica is the
specific goal.
And although fused silica and quartz has a dip in transmission at ~2700 nm
to about 5% (= 95 % absorbance):
http://www.pgo-online.com/intl/katalog/7980.html
there are high temperature (900C) glasses with better transmission at 2700nm
http://www.pgo-online.com/intl/katalog/vycor.html
and titanium glasses with higher melting points than fused silica but
equivalent or better transmission that is used for telescopes:
http://www.pgo-online.com/intlframes/catalogindexset.html
And there are even glasses used for halogen lights that block the visible
light while passing IR (which they have to or they would melt -- Remember
where we started?)
http://www.corning.com/lightingmaterials/images/Vycor_7950.pdf
In other words, Rod Speed is spectacularly wrong in the premise of his
foul-mouth bluster which was QUOTE: "There is NO alternative to the use of
fused silica ".
Quod demonstratum est.
This has little to do about HA and so is a tempest in a teapot -- except for
figuring out who blusters and who doesn't..
... Marc
MFH...@nothydrologistnot.com
Robert L. Bass
Your choice of words. :^)
> What was being discussed was why a
> fused silica envelope is used with halogens.
The subject is usuing mirrors to extend IR remore around a corner.
> >> Even you should be able to put your hand in front of
> >> a conventional incandescent bulb of similar power like
> >> a PAR 38 and notice how hot your hand gets.
>
> > And???
>
> Clearly the glass which isnt fused silica with those, is passing the IR.
Did I say it wouldn't?
>> BTW, your previous statements about halides were wrong.
>
> Crap.
True, but I prefer a milder term so I chose the word, "wrong."
>> Take a little time and read up on the subject.
>
> No thanks, its you that doesnt have
> a clue about the basics with halogens.
I trust you'll now share a single verifiable source of engineering data
showing I'm wrong. [Definitely NOT holding our breath].
>> Then get back to us.
>
> How many of you is there between those ears ?
"Us" refers to a subset of the news group -- those who know how halides
work. "You" refers to someone who apparently does not know the subject.
OurFamily
everyone.
Nothing like getting the "think tank" all stirred up..
"G. Morgan" <wacog...@yahoo.com> wrote in message
news:38a36v4o6vrahsj4i...@4ax.com...
> Some guy named "OurFamily" <NotR...@ptd.net> Proclaimed on Wed, 26
> Feb 2003 21:05:00 GMT,
>
> >I am looking to place my stereo,vcr, and dvd in the room next to our
family
> >room through the doorway and around the corner. What is the best way to
> >extend the remote control or make sure that it will work in this way.
Any
> >ideas. Not that far but the corner I think will cause a problem.
> >
>
> So did you get your answer "OurFamily" ?? :-)
>
> Now you know all about halogen lamps and glass! Or are you more
> confused than ever? Like me.
>
> (my reply to you was to say a mirror is not the way to go, I had no
> idea a physics discussion (*brawl*) would break out, get a IR
> repeater.)
>
> LOL!!!
>
> -Graham
>
>
Dave Houston
>I am "almost" sorry I asked : ) Looking into the pyrmid type now. Thanks
>everyone.
>
> Nothing like getting the "think tank" all stirred up..
You didn't stir anything - I did that. It's been boringly calm lately. ;)
FWIW, I also think the Powermids are the way to go as long as you can shield
the sending unit from sunlight, fluorescents, etc.
---
http://www.laser.com/dhouston/
Rod Speed
'let it lie' instruction to others actually applys to itself,
<MFH...@nothydrologistnot.com> wrote in message
news:5i836vo950m09mi3i...@4ax.com...
> Rod Speed <rod_...@yahoo.com> wrote
>> There is NO alternative to the use of fused silica, and the IR transmission
>> is just another factor in the design of how the fused silica is used.
> So Rod Speed is under the misconception that there are no
> alternatives to fused silica and quartz for making halogen lamps
What was clearly being discussed was why fused silica is used
instead of ordinary glass, you pathetic excuse for a bullshit artist.
> which -- along with a foul mouth -- is part of his problem.
Even you should be able to bullshit your way out of your
predicament MUCH better than that pathetic effort, Hult.
> I wrote that ""Fused silica itself is an excellent transmitter of
> IR, which is part of why it is used in making halogen lamps."
And that aint actually the reason that fused silica is used instead
of ordinary glass, you pathetic excuse for a bullshit artist.
> which is what has got Rod so bent out of shape.
Just another of your pathetic little drug crazed fantasys.
All the rest of your completely irrelevant pathetic
excuse for bullshit flushed where it belongs.
Rod Speed
>> What was being discussed was why a
>> fused silica envelope is used with halogens.
> The subject is usuing mirrors to extend IR remore around a corner.
The subject was irrelevant to that particular
sub thread, as often happens with usenet.
>>>> Even you should be able to put your hand in front of
>>>> a conventional incandescent bulb of similar power like
>>>> a PAR 38 and notice how hot your hand gets.
>>> And???
>> Clearly the glass which isnt fused
>> silica with those, is passing the IR.
> Did I say it wouldn't?
Did I say you did ?
>>> BTW, your previous statements about halides were wrong.
>> Crap.
> True, but I prefer a milder term so I chose the word, "wrong."
Even you should be able to bullshit your way out
of your predicament better than that puerile effort.
>>> Take a little time and read up on the subject.
>> No thanks, its you that doesnt have
>> a clue about the basics with halogens.
> I trust you'll now share a single verifiable
> source of engineering data showing I'm wrong.
Already did.
http://home.howstuffworks.com/question151.htm
Nothing like your
>>> passing a current between two electrodes through a metal vapor.
> [Definitely NOT holding our breath].
You've never said just how many of you there is between those ears.
>>> Then get back to us.
>> How many of you is there between those ears ?
> "Us" refers to a subset of the news group
> -- those who know how halides work.
Even Hult was never stupid enough to claim thats how halogens
work, so we're still just left with those between YOUR ears.
> "You" refers to someone who apparently does not know the subject.
In fact everyone can see for themselves that that
is you. Halogens still use a filament, no 'passing a
current between two electrodes through a metal vapor.
The halide process is just to minimise the erosion of that
filament at the very high filament temperatures used.
Robert L. Bass
> silica is used instead of ordinary glass, you pathetic
> excuse for a bullshit artist.
Actually, the subject was extending IRfrom one's remote around a corner.
The thread has taken a few turns since then. However, you're still wrong.
I suspect you realize that but don't want to admit it. :^)
> > which -- along with a foul mouth -- is part of his problem.
>
> Even you should be able to bullshit your way out
> of your predicament MUCH better than that pathetic
> effort, Hult.
Profanity substituted for logic is a sure sign the poster has lost the
argument.
Robert L. Bass
>>> fused silica envelope is used with halogens.
>
>> The subject is usuing mirrors to extend IR
>> remore around a corner.
>
> The subject was irrelevant to that particular
> sub thread, as often happens with usenet.
Actually, it's called USENET. But we'll ignore small errors while you hold
onto much larger ones.
>> Did I say it wouldn't?
>
> Did I say you did ?
Does anyone care who said what at this point?
>> BTW, your previous statements about halides were wrong.
>
> Crap.
True, but I prefer a milder term so I chose the word, "wrong."
>
> Even you should be able to bullshit your way out
> of your predicament better than that puerile effort.
Umm, you tried that one on Marc already. Have you anything new to add?
> http://home.howstuffworks.com/question151.htm
That site has some helpful information on it but it's not complete on the
subject.
Rod Speed
Robert L. Bass <rober...@comcast.net> wrote in
message news:8tmcnV30ff1...@giganews.com...
>> What was clearly being discussed was why
>> fused silica is used instead of ordinary glass,
>> you pathetic excuse for a bullshit artist.
> Actually, the subject was extending IRfrom one's remote
> around a corner. The thread has taken a few turns since then.
Must be one of those rocket scientist pathetic excuses for a bullshit artist.
Reams of your pathetic excuse for bullshit flushed where it belongs.
> Profanity substituted for logic is a sure
> sign the poster has lost the argument.
Even you should be able to bullshit your way out of your
predicament MUCH better than that pathetic effort.
Rod Speed
>>>> What was being discussed was why a
>>>> fused silica envelope is used with halogens.
>>> The subject is usuing mirrors to extend
>>> IR remore around a corner.
>> The subject was irrelevant to that particular
>> sub thread, as often happens with usenet.
> Actually, it's called USENET.
Wrong. As usual.
> But we'll ignore small errors while you hold onto much larger ones.
Even you should be able to bullshit your way out of your
predicament MUCH better than that pathetic effort, Bass.
>>> Did I say it wouldn't?
>> Did I say you did ?
> Does anyone care who said what at this point?
Why did you ask your question then ?
>>> BTW, your previous statements about halides were wrong.
>> Crap.
> True, but I prefer a milder term so I chose the word, "wrong."
Your problem.
>>>>> Take a little time and read up on the subject.
>>>> No thanks, its you that doesnt have
>>>> a clue about the basics with halogens.
>>> I trust you'll now share a single verifiable
>>> source of engineering data showing I'm wrong.
>> Already did.
>> http://home.howstuffworks.com/question151.htm
> That site has some helpful information on
> it but it's not complete on the subject.
Doesnt need to be 'complete'. It clearly says that halogens dont work
by 'passing a current between two electrodes through a metal vapor'
Thanks for that completely superfluous evidence that
you couldnt bullshit your way out of a wet paper bag
even if your pathetic excuse for a 'life' depended on it.
MFH...@nothydrologistnot.com
in message <b3tvbe$1pvrej$1...@ID-69072.news.dfncis.de>:
>Some hypocrite that obviously doesnt believe that his
>'let it lie' instruction to others actually applys to itself,
><MFH...@nothydrologistnot.com> wrote in message
>news:5i836vo950m09mi3i...@4ax.com...
>> Rod Speed <rod_...@yahoo.com> wrote
>
>>> There is NO alternative to the use of fused silica, and the IR
>>> transmission is just another factor in the design of how the
>>> fused silica is used.
>
>> So Rod Speed is under the misconception that there are no
>> alternatives to fused silica and quartz for making halogen lamps
>
>What was clearly being discussed was why fused silica is used
>instead of ordinary glass, you pathetic excuse for a bullshit artist.
Wrong. Go back and read it.
Now that Rod Speed has confirmed yet again that he erroneously thought that
the only two alternatives were "ordinary" glass and fused silica, which I
showed was nonsense in my previous post, let's look at some more of Rod's
fundamental misconceptions and how that relates to his one track mind on
what is important in design and realization of regenerative halogen
lighting.
Quote: "In fact the reason its [ fused silica] used has nothing to do
with IR transparency as you initially claimed."
Quote: " There is no practical difference in the IR transparency with
'fused silica' and normal glass used in windows"
Quote "Because it [IR transmissivity of fused silica] aint 'part of why it
is used in making halogen lamps' "
First off, the IR absorbance of DIFFERENT glasses that ARE USED for making
halogen lamps varies considerably. As I showed in my previous posts, the
absorbance of IR at 2700 nanometers varies from <5 % to 95% ! (whether Rod
Speed knows it or not).
This is important because reality is that only ~8% of the energy dissipated
by a regenerative halogen lamp is visible light. Most of the remainder is
IR. Since the purpose of the lamp is to produce visible light, most halogen
lamps are 90+% transmissive in the visible region and much of the heat comes
from IR.
The heating of the bulb envelope comes from conduction of heat through the
filament to the substrate, by conduction of heat through the halogen vapor,
and by absorption of light energy by the bulb.
The latter is absolutely critical in the design. If, we assume, as is
conventional , that: 1) that a long skinny halogen lamp is sufficiently long
for the end effects to be neglected for a first-order approximation, and
2), that the dissipation of heat by surface of the bulb to the surrounding
environment is approximately proportional to its surface area, by
recognizing that heat emitted as light is constant regardless of the bulb
diameter, we arrive at the conclusion that the temperature of the envelope
is (roughly) inversely proportional to the diameter of a long skinny tube..
That is,
the lamp surface temperature, T, is proportional to 1/diameter x integral of
(absorbance @ wavelength y x emission @wavelength y) over the frequencies
emitted.
The emission spectrum of tungsten fi;aments is constrained by its physical
properties and the characteristics of the light sought (typically continuous
spectrum 3200-3400 K), so to reach and maintain the envelope temperature
needed for regenerative halogen lighting to work,
two principal variables available for manipulation to reach the target
temperature (which is what Rod Speed perseverates about) are the bulb
diameter and the glass absorbance + reflectance characteristics.
Because much of the non-visible light energy is in the IR range, the IR
absorbance characteristics become absolutely critical in bulb design
(whether Rod Speed knows it or not).
A glimpse into the important of IR control in the design and manufacture of
halogen lamps can be seen in the development of lamps that use new coatings
to increase the reflectivity of the inner bulb to keep the IR *within* the
volume surrounded by material with high IR reflectance. See
http://www.sylvania.com/business/emagazine/retail_1/infrared/infrared.html
That Rod doesn't know this matters not. What may be of interest to HA is
that better halogen lamps are being developed (and many use neither fused
silica/quartz, and all are designed with IR characteristics of the bulb as
an important design criteria).
Hope This Helps ... Marc
MFH...@nothydrologistnot.com
MFH...@nothydrologistnot.com
message <5i836vo950m09mi3i...@4ax.com>:
On Mon, 3 Mar 2003 09:07:39 +1100, "Rod Speed" <rod_...@yahoo.com> wrote
in message <b3tvbe$1pvrej$1...@ID-69072.news.dfncis.de>:
>Some hypocrite that obviously doesnt believe that his
>'let it lie' instruction to others actually applys to itself,
><MFH...@nothydrologistnot.com> wrote in message
>news:5i836vo950m09mi3i...@4ax.com...
>> Rod Speed <rod_...@yahoo.com> wrote
>
>>> There is NO alternative to the use of fused silica, and the IR
>>> transmission is just another factor in the design of how the
>>> fused silica is used.
>
>> So Rod Speed is under the misconception that there are no
>> alternatives to fused silica and quartz for making halogen lamps
>
>What was clearly being discussed was why fused silica is used
>instead of ordinary glass, you pathetic excuse for a bullshit artist.
Wrong. Go back and read it.
Now that Rod Speed has confirmed yet again that he erroneously thought
that the only two alternatives were "ordinary" glass and fused silica,
which I showed was nonsense in my previous post (see refs above) , let's
skinny tube and the sum of the products of the absorption coefficients x
light intensities.
That is,
the lamp surface temperature, T, is proportional to 1/diameter x integral
of(absorbance @ wavelength y x emission @wavelength y) over the frequencies
emitted.
The emission spectrum of a tungsten filament is constrained by its physical
properties and the characteristics of the light sought (typically
continuous spectrum 3200-3400 K), so to reach and maintain the envelope
temperature needed for regenerative halogen lighting to work,
two principal variables available for manipulation to reach the target
temperature T (which is what Rod Speed perseverates about) are the bulb
diameter and the glass absorbance + reflectance characteristics.
Because much of the non-visible light energy is in the IR range, the IR
absorbance characteristics become absolutely critical in bulb design
(whether Rod Speed knows it or not).
A glimpse into the important of IR control in the design and manufacture of
halogen lamps can be seen in the development of lamps that use new coatings
to increase the reflectivity of the inner bulb to keep the IR *within* the
volume surrounded by material with high IR reflectance. See
http://www.sylvania.com/business/emagazine/retail_1/infrared/infrared.html
"Infrared capsules in CAPSYLTYE (r) IR (TM) halogen PARs radically reduce
energy costs".
Rod Speed
Some hypocrite that obviously doesnt believe that his
'let it lie' instruction to others actually applys to itself,
<MFH...@nothydrologistnot.com> wrote in message
> Rod Speed <rod_...@yahoo.com> wrote
>> <MFH...@nothydrologistnot.com> wrote
>>> Rod Speed <rod_...@yahoo.com> wrote
>> What was clearly being discussed was why fused silica is used
>> instead of ordinary glass, you pathetic excuse for a bullshit artist.
> Wrong.
Right.
> Go back and read it.
No point.
Reams of your pathetic posturing flushed where it belongs.
MFH...@nothydrologistnot.com
in message <b3up17$1oqosu$1...@ID-69072.news.dfncis.de>:
The "let it lie" suggestion was for Robert, not you, and it was directed
toward ignoring your antisocial behavior in the hope that your dysfunction
was temporary. But this seems not to be. Anyone can be redeemed, though.
The halogen cycle used in regenerative bulb works down to about 260C which
is far lower than the 1500C melting point of fused silica and even the 900C
of aluminosilicate glasses that are also used for halogen lamps that Don
Speed claimed didn't exist.
So the need/use of fused silica is not the high melting and softening point
of fused silica, per se, as Rod Speed so tediously claims, but rather other
properties including the low coefficient of thermal expansion that I
mentioned previously.
In other words, Rod Speed's pathologic fixation on the importance of high
melting point of the bulb material is misplaced for other reasons too.
But while were are here fixing Don Speed's misinformation, let's deal with
another urban legend that he has been helping to propagate in this thread --
namely that halogen lights should not be dimmed -- since that does relate to
Home Automation and others may be misinformed by his statements.
Modern halogens can be dimmed just fine for significant parts of the time
that they are in use with little if any impairment in function or decrease
in life. In fact, once dimming is great enough to be distinctly noticeable,
the 13th power law of voltage v. filament life pertains and the life of the
filament is increased, not decreased, as it is with conventional
incandescent lamps.
Moreover, darkening of the lamp due to deposition of tungsten is mostly
reversible. I have some 75 watt 10degree PAR 16 spots that for ~two years
have been dimming up over a period of more than an hour in the morning and
down over a comparable period in the evening, tracking the monitored outdoor
sunlight, that show no sign of darkening. Any minor deposition of tungsten
during the dimmed periods is re-sublimated when the temperature is raised
again.
I suspect that part of the reason for the lack of darkening (tungsten
deposition) may be due to the fact that dimming increases the proportion of
the total energy emitted that is in the infrared, so the effect of dimming
on temperature is less than might be expected than if dimming affected all
wavelengths equally (IOW, back to the importance of IR in bulb heat budget).
... Marc
MFH...@nothydrologistnot.com
Rod Speed
'let it lie' instruction to others actually applys to itself,
<MFH...@nothydrologistnot.com> wrote in message
> Rod Speed <rod_...@yahoo.com> wrote
>> <MFH...@nothydrologistnot.com> wrote
>>> Rod Speed <rod_...@yahoo.com> wrote
>>>> <MFH...@nothydrologistnot.com> wrote
>>>>> Rod Speed <rod_...@yahoo.com> wrote
>>>> What was clearly being discussed was why fused silica is used
>>>> instead of ordinary glass, you pathetic excuse for a bullshit artist.
>>> Wrong.
>> Right.
>>> Go back and read it.
>> No point.
>> Reams of your pathetic posturing flushed where it belongs.
> The "let it lie" suggestion was for Robert, not you,
Never said anything about me as far as that was concerned.
Robert L. Bass
G. Morgan wrote:
>
> Yeah okay Rob but I have a question for you: Is glass a
> liquid or a solid?
JtS
you two sit around and pontificate this stuff?
I'm sure it's relevant to home automation-
what a pair- of nuts!
Frank Olson
news:dEudnW_FTMg...@giganews.com...
> Curiously, IR apparently also passes through the glass in a crystal vase
in
> my family room. It also passes through water. The reason I know this is
I
> can place the remove from my satellite dish against the glass and my
> fighting fish ignores it. But when I hold down the volume up or down keys
> he comes right over to investigate it.
>
> This leads to another interesting (and useless) factoid. Fighting fish
can
> see IR.
Some satellite remotes use RF... You sure yours doesn't??? I haven't tried
your trick with the fighting fish... I've got three (in separate tanks)...
I'll give it a "whirl" this evening and let you know what happens... :-)
--
Frank E. Olson
http://www.alt-security-alarms.com
Free listings for qualified industry professionals, dealers & suppliers.
Please visit the unofficial web site to view FAQ and participant
information.
Robert L. Bass
> Some satellite remotes use RF... You sure yours doesn't??? I haven't
tried
> your trick with the fighting fish... I've got three (in separate
tanks)...
> I'll give it a "whirl" this evening and let you know what happens... :-)
Make sure you don't use a halogen bulb in the vicinity or Rod will argue
with you about the need for a quartz fish bowl. :^)
MFH...@nothydrologistnot.com
<rober...@comcast.net> wrote in message
<eLKcnQ3uYuA...@giganews.com>:
>Mine uses IR. AFAIK, my fish does not receive RF.
>
>> Some satellite remotes use RF... You sure yours doesn't??? I haven't
>tried
>> your trick with the fighting fish... I've got three (in separate
>tanks)...
>> I'll give it a "whirl" this evening and let you know what happens...
:-)
>
>Make sure you don't use a halogen bulb in the vicinity or Rod will argue
>with you about the need for a quartz fish bowl. :^)
>
A c.h.a reader emailed me that a google of usenet for
" <rod_...@yahoo.com> bullshit " yields more than 8,500 hits
Seems that he has quite the fascination for bovine scatology.
... Marc
MFH...@nothydrologistnot.com
Robert L. Bass
Rod Speed
> Yeah okay Rob but I have a question
> for you: Is glass a liquid or a solid?
Completely irrelevant to whether it can be used as a reflector for IR remotes.
The short story is that its solid enough, stupid.
> (have fun!)
Stop trying to order me about !!!
> Rod Speed <rod_...@yahoo.com> wrote
>> G. Morgan <wacog...@yahoo.com> wrote
>>> dhou...@fuse.net (Dave Houston) wrote
>>>> IR does not pass through glass.
>>>> David Petrone <dav...@advacon.com> wrote
>>>>> And a convex mirror would probably make the placement less critical.
>>> Yup, D. Houston is right.
>> Fraid not.
>>> A mirror won't work.
>> Odd, it does for me.
>>> D. Petrone is not correct.
>> Fraid so.
Rod Speed
Frank Olson <Use_the_e...@alt-security-alarms.com> wrote
in message news:19s9a.452$UV6....@news1.telusplanet.net...
> Robert L. Bass <rober...@comcast.net> wrote
>> Curiously, IR apparently also passes through the glass in a crystal
>> vase in my family room. It also passes through water. The reason
>> I know this is I can place the remove from my satellite dish against
>> the glass and my fighting fish ignores it. But when I hold down the
>> volume up or down keys he comes right over to investigate it.
>> This leads to another interesting (and useless)
>> factoid. Fighting fish can see IR.
> Some satellite remotes use RF... You sure yours doesn't??? I haven't
> tried your trick with the fighting fish... I've got three (in separate tanks)...
> I'll give it a "whirl" this evening and let you know what happens... :-)
Its just a ploy to get you to fry your fish.
He flogs fish too |-)
Should be no surprise given his name, likely flogging his relatives |-)
Rod Speed
<MFH...@nothydrologistnot.com> wrote in message
news:02ad6v8a4uq863rg9...@4ax.com...
> Seems that he has quite the fascination for bovine scatology.
And you for pathetic excuse for bullshit.
Greg Letiecq
>
> I'm not trying to order you about (whatever that means). Glass is a
> liquid. You fell right into the trap. HAHAHA!! Shows you are not a
> physicist for one, and by your response shows your a troll. Who is
> stupid now?
>
> -Graham
>
I really want this thread to die, as it's getting awfully old watching all
this pointless sniping, but I just have to get this clarified. I've heard
statements that glass is a liquid because it will supposedly deform over
time
and flow. I've also seen stained glass that's several hundreds of years
old and never observed any apparent flowing behavior. In all my
experience, glass has seemed to be fully solid to me, and will liquify
when it's heated.
So if glass is supposedly liquid at room temperature, at what
temperature is it solid? And if I heat it to several thousand degrees
and get it to act like a liquid, have I not changed it's state from
solid to liquid?
What's up with this?
Greg
Robert L. Bass
random, non-structured manner in which its atoms bond. Metallic and
crystalline substances form repeatable, structured atomic bonds as they cool
from liquid to a solid state. Glass does not. Its atoms behave just like a
liquid -- a highly viscous one but a liquid just the same.
BTW, the type of glass called "crystal" is not actually crystal. It's just
a name.
Regards,
Robert L Bass
=============================>
Bass Home Electronics
ASA Approved Vendor
http://www.Bass-Home.com
2291 Pine View Cir
Sarasota, FL 34231
877-722-8900 Sales & Support
941-925-9747 Fax
rober...@comcast.net
=============================>
> I really want this thread to die, as it's getting awfully old watching all
Rod Speed
> Rod Speed <rod_...@yahoo.com> wrote
>>> Yeah okay Rob but I have a question
>>> for you: Is glass a liquid or a solid?
>> Completely irrelevant to whether it can be used as a reflector for IR remotes.
>> The short story is that its solid enough, stupid.
>>> (have fun!)
>> Stop trying to order me about !!!
> I'm not trying to order you about (whatever that means).
That was a joke, Joyce. Didnt seem appropriate to put a smiley on an order.
> Glass is a liquid. You fell right into the trap.
Just another of your pathetic little drug crazed fantasys.
It should be obvious even to you that I did nothing of the kind.
> HAHAHA!!
Take that medication.
> Shows you are not a physicist for one,
Just another of your pathetic little drug crazed fantasys.
> and by your response shows your a troll.
Just another of your pathetic little drug crazed fantasys.
> Who is stupid now?
Try one of those mirror things. Best use one that you
dont care about, because its guaranteed to break.
Rod Speed
Greg Letiecq <glet...@nowhere.org> wrote in
message news:3E6836ED...@nowhere.org...
> I really want this thread to die,
So dont be a wimp, get out the elephant gun.
> but I just have to get this clarified.
or what ?
> I've heard statements that glass is a liquid because
> it will supposedly deform over time and flow.
Thats basically a myth at normal temperatures.
> I've also seen stained glass that's several hundreds of years
> old and never observed any apparent flowing behavior.
And thats the myth. That effect is just due to how the glass was
originally made. It was only with the invention of the float process
that that variable thickness effect was eliminated. Float glass doesnt
become thicker over time at the bottom edge, at normal temps.
> In all my experience, glass has seemed to be
> fully solid to me, and will liquify when it's heated.
Technically its rather more complicated than that.
> So if glass is supposedly liquid at room
> temperature, at what temperature is it solid?
Its more complicated than that too.
> And if I heat it to several thousand degrees and get it to act
> like a liquid, have I not changed it's state from solid to liquid?
Fraid not.
> What's up with this?
Its just another of those areas thats more complicated than it first looks.
MFH...@nothydrologistnot.com
<rober...@comcast.net> wrote in message
<_xmdnSzTbeV...@giganews.com>:
>No sniping here, Greg. It's considered a super-cooled liquid because of
>the random, non-structured manner in which its atoms bond. Metallic and
>crystalline substances form repeatable, structured atomic bonds as they
>cool from liquid to a solid state. Glass does not. Its atoms behave just
>like a liquid -- a highly viscous one but a liquid just the same.
>
>BTW, the type of glass called "crystal" is not actually crystal. It's
just
>a name.
>
>Regards,
>Robert L Bass
A conceivable reason this might be of interest to c.h.a participants
concerns the transition of fused silica from glass to crystalline form
which is a principal failure mode for halogen lights.
You may be familiar with admonishments to not touch the bulb of a halogen
lamp because doing so will cause the lamp to fail. This is because pure
silica "glass" used in halogen lamps (either as the mis-named "quartz" or
fused silica) spontaneously devitrifies (changes to crystalline form) at
about 1100C.
If there is hot spot created by dark material on the lamp (eg: burned oil
from your fingers) or metals (eg: NaCl from sweat), the devitrification can
occur at lower temperatures. The process creates the mineral cristobalite
which I mentioned earlier in this thread that has the identical composition
but is denser than fused silica and so it cracks when the change occurs
(effectively a step-change in the thermal expansion/contraction). This is
another of the reasons why Rod Speed's ignorant perseveration on the
unimportance of SiO2 structure in design of regenerative halogen lamps (and
the patent nonsense about their being only one possible substance to make
them with) is wrong.
The take-home for c.h.a folks might be to not sweat it -- or at least to
not sweat on their Torchiere-style lamps ... and more importantly, not to
let the lamps overheat. (The ubiquitous Torchiere Halogen lamp is also a
significant fire hazard IMO and is banished from many institutions).
HTH ... Marc
MFH...@nothydrologistnot.com
Rod Speed
<MFH...@nothydrologistnot.com> wrote in message news:g90i6vcetf6lkirko...@4ax.com...
Even you should be able to posture more convincingly than that
pathetic excuse for bullshit, Hult. Doesnt have a damned thing to
do with why that particular envelope is used in the first place.