A Home cinema forum. HomeCinemaBanter

If this is your first visit, be sure to check out the FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection below.

Go Back   Home » HomeCinemaBanter forum » Home cinema newsgroups » UK digital tv
Site Map Home Register Authors List Search Today's Posts Mark Forums Read Web Partners

Using mobile phone as an internet radio



 
 
Thread Tools Display Modes
  #41  
Old October 4th 12, 09:48 AM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
Jasen Betts
external usenet poster
 
Posts: 8
Default Using mobile phone as an internet radio

On 2012-10-03, Geoffrey S. Mendelson wrote:


My choices are to once a week clean out a jam, and clean the feed roller;
print something everyday (a waste of paper)


load the paper tray with scrap paper, use the bypass when you want to
print something for real.

another option is to make a document with no ink and print that each day
at the end of the week collect the blank pages from the output tray
and put them back in the input tray.

--
⚂⚃ 100% natural

--- news://freenews.netfront.net/ - complaints: ---
  #42  
Old October 4th 12, 03:18 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
chris
external usenet poster
 
Posts: 35
Default Using mobile phone as an internet radio

On 03/10/2012 00:49, William Sommerwerck wrote:
"David Woolley" wrote in message
...
William Sommerwerck wrote:


My new computer has a solid-state "hard disk", and you
wouldn't believe how fast it boots up, or how fast programs
start to run.


These, if flash memory, do have a definite wear out mechanism,
although they do try to avoid writing to the same spot, even if the
software does, to mitigate this.


Correct. SSDs are an exception. They contain "leveling" software that makes
sure the disk is written to evenly. The Crucial disk I use is spec'd at
about 40TB of total writes.


For most usage scenarios the theoretical lifetimes of modern SSDs are
longer than HDDs.

  #43  
Old October 4th 12, 04:03 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
Phil Hobbs
external usenet poster
 
Posts: 15
Default Using mobile phone as an internet radio

On 10/03/2012 09:41 PM, Jeff Liebermann wrote:
On Wed, 03 Oct 2012 10:32:57 -0400, Phil Hobbs
wrote:

I don't know of any data that supports this common idea, but I'd be
interested in reading about it if anybody's actually done the experiment
carefully.


It's an accelerated life test. The deration curve of the incandescent
light bulb is well known and assumed to be
(Vapplied/Vdesign)^-12 to ^-16 * Life at design voltage
http://www.welchallyn.com/documents/Lighting/OEM_Halogen_Lighting/MC3544HPX_Catalog_2_11_09.pdf
See Fig 5 on Pg 5 for the graph. Nobody wants to wait 1000 hours for
a bulb to blow. So, they increase the applied voltage, which
dramatically decreases the lifetime down to reasonable test times.
Using a rack of bulbs, they obtain an average (or median) lifetime at
the higher voltage. Then, they work backwards on the curve to
estimate what it would be at the design voltage.


You can't run an accelerated life test when the exponent isn't known
more accurately than 12 to 16.


When I was specifying lamps for a direction finder for the USCG, I had
to deal with minimum lifetime specs. I asked the vendor (Dialight)
how they tested their T-1 3/4 bulbs and was told that they did an
accelerated lifetime test on a few bulbs from each lot to insure
adequate lifetime along with the usual sampled 1.5% AQL failure test.

Electromigration is a smaller effect in an AC bulb, since
the leading order effect cancels.


Yep. As I understand it (possible wrong), AC filaments break in the
middle, mostly from vibration flexing.


I don't think so, because there's no mechanism for that, as I said. The
wire is fully annealed at all times, so there's no possibility of
progressive fatigue failure.


I suspect that the notion that cycling is hard on bulbs comes from the
way that the bulb often fails at turn-on, when the thinnest hot spot
vapourizes before the rest of the filament has a chance to come up to
temperature and reduce the inrush current.


Yep. See my comments on the relatively high failure rate on the
40watt theater marquee lamps due to cycling. The same lamps in the
lobby and foyer were not cycled and seemed to last forever.


I was actually disagreeing with you. There are lots of possible reasons
for the marquee lights failing prematurely. I'm not a tungsten expert
myself, so I'd be very interested in seeing actual data that shows a
dramatic shortening of life due to cycling. I'm not saying it's
impossible, just that I haven't seen any such data.


The tungsten in the lamp is run within a few hundred kelvins of its
melting point, so it's always in the fully annealed state, which ought
to mean that there are no metal fatigue mechanisms operating, just
material migration due to sublimation.


Yep, but different failure mode. When the extremely thin layer of
tungsten plating evaporates, the light becomes dimmer. Below some
brightness level, it is considered to have failed. However, most such
tungsten coated filaments fail due to corrosion of the base steel
alloy wire which is exposed to the internal gases inside the bulb
after the tungsten evaporates. The gases (mostly nitrogen and some
argon) are inert, but there's a little water vapor outgassing from
heating the glass envelope, which eventually corrodes the filament.
Other failure modes are hot spots and notches caused by manufacturing
variations and tungsten evaporation.


The filament isn't tungsten-plated, it's pure tungsten or a low alloy.
The brightness drop comes from tungsten condensing on the envelope.

And the connecting wire isn't plain steel, it's generally Dumet,
http://www.jlcelectromet.com/dumetwire.htm

which is a 42% Ni steel with OFHC copper or nickel plating.

You're making a lot of that up. I'd still like to see
carefully-collected data.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
  #44  
Old October 4th 12, 06:43 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
Jeff Liebermann
external usenet poster
 
Posts: 25
Default Using mobile phone as an internet radio

On Thu, 04 Oct 2012 10:03:21 -0400, Phil Hobbs
wrote:

On 10/03/2012 09:41 PM, Jeff Liebermann wrote:
On Wed, 03 Oct 2012 10:32:57 -0400, Phil Hobbs
wrote:

I don't know of any data that supports this common idea, but I'd be
interested in reading about it if anybody's actually done the experiment
carefully.


It's an accelerated life test. The deration curve of the incandescent
light bulb is well known and assumed to be
(Vapplied/Vdesign)^-12 to ^-16 * Life at design voltage
http://www.welchallyn.com/documents/Lighting/OEM_Halogen_Lighting/MC3544HPX_Catalog_2_11_09.pdf
See Fig 5 on Pg 5 for the graph. Nobody wants to wait 1000 hours for
a bulb to blow. So, they increase the applied voltage, which
dramatically decreases the lifetime down to reasonable test times.
Using a rack of bulbs, they obtain an average (or median) lifetime at
the higher voltage. Then, they work backwards on the curve to
estimate what it would be at the design voltage.


You can't run an accelerated life test when the exponent isn't known
more accurately than 12 to 16.


True, but I believe that's the range expected from different types of
light bulbs (nitrogen filled, halogen, vaccuum), and not the range
expected for a given device. I suspect that more accurate exponent
value could be empirically determined for a given device, and later
used only for that device.

Yep. As I understand it (possible wrong), AC filaments break in the
middle, mostly from vibration flexing.


I don't think so, because there's no mechanism for that, as I said. The
wire is fully annealed at all times, so there's no possibility of
progressive fatigue failure.


http://en.wikipedia.org/wiki/Incandescent_light_bulb#Reducing_filament_evaporat ion
One of the problems of the standard electric light bulb is
evaporation of the filament. Small variations in resistivity
along the filament cause "hot spots" to form at points of
higher resistivity; a variation of diameter of only 1% will
cause a 25% reduction in service life. The hot spots evaporate
faster than the rest of the filament, increasing resistance
at that point a positive feedback that ends in the familiar
tiny gap in an otherwise healthy-looking filament.

Note the photo of the filament with a break in the middle. When I was
quite young, I would break burnt out AC light bulbs to see what was
inside. If the filament was intact, the break was always somewhere
near the middle. If a piece broke off, one end of the broken piece
was usually near the middle. In later years, I would look at the
remains of DC panel lights (usually type 47 for old Motorola radios)
and noted that the breaks were always near the supporting terminals,
probably due to metal migration.

I suspect that the notion that cycling is hard on bulbs comes from the
way that the bulb often fails at turn-on, when the thinnest hot spot
vapourizes before the rest of the filament has a chance to come up to
temperature and reduce the inrush current.


Yep. See my comments on the relatively high failure rate on the
40watt theater marquee lamps due to cycling. The same lamps in the
lobby and foyer were not cycled and seemed to last forever.


I was actually disagreeing with you. There are lots of possible reasons
for the marquee lights failing prematurely. I'm not a tungsten expert
myself, so I'd be very interested in seeing actual data that shows a
dramatic shortening of life due to cycling. I'm not saying it's
impossible, just that I haven't seen any such data.


So much for my anecdotal data. My theater marquee experience was in
about 1966. The theater actually did keep records so that they could
stock enough replacement bulbs, but I don't have copies of any of
that.

I tried Googling for similar repetative on-off tests and didn't find
anything. If I have time, I'll try again. I must admit that the lack
of test data does look suspicious. Perhaps sending the idea to
Mythbusters and have them runs a test?

The filament isn't tungsten-plated, it's pure tungsten or a low alloy.
The brightness drop comes from tungsten condensing on the envelope.


Oops. I thought it was plated.

And the connecting wire isn't plain steel, it's generally Dumet,
http://www.jlcelectromet.com/dumetwire.htm

which is a 42% Ni steel with OFHC copper or nickel plating.

You're making a lot of that up. I'd still like to see
carefully-collected data.


No, not fabricated. It's my reliance on my memory in an area that I'm
not familiar with. I tried Googling for the wire used, couldn't find
much, and made a bad guess. The plating came from somehow getting
thorium coated tungsten wire used in vacuum tubes mixed up with light
bulbs. Sorry for the errors and muddle.

Cheers
Phil Hobbs


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #45  
Old October 4th 12, 07:05 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
Jeff Liebermann
external usenet poster
 
Posts: 25
Default Using mobile phone as an internet radio

On Wed, 3 Oct 2012 10:34:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Tom Biasi wrote:
Not so. With mechanical devices, regular moderate use provides a longer
useful lifetime than using the device only rarely.


I don't agree but will say no more.


Laser printers. I have given away for parts several laser printers because
they sat unused 99% of the time, and started to jam when I printed the
one or two pages a month I needed them for.


I've seen flat spots on laser printers. However, just running a few
pages through the printer usually returns them to normal. If not, use
some rubber roller restorer to soften the rubber.
http://www.fixyourownprinter.com/specials/misc/all/S03

In my experience, many printer jams are caused by paper slippage on
the rollers. Usually, it's the white paper dust that causes slippage,
but it can easily be household dust accumulated over the time the
printer was idle. Maybe hitting the printer with a compressed air
blast before operating might help.

Another slippage problem is when the rubber surface becomes glazed or
polished. The rubber roller restorer will take the surface gloss off
the rollers, and improve the traction, but if there's any rubber wear,
the roller(s) should be replaced.

Not only did the rubber wheels dry out and lose their ability to grab paper,
they flatten where they are pressed against something.

I have a perfectly good Samsung laser printer in that condition now.


Ugh. I don't have much nice to say about Samsung printers. They're
cheap, function adequately, use overpriced toner carts, and don't last
very long. I've never really done an autopsy to isolate a culprit.
The usual end of life symptoms are either paper jams or flimsy broken
plastic parts.

My choices are to once a week clean out a jam, and clean the feed roller;
print something everyday (a waste of paper); spend $15 for a new roller
(including postage) and an hour to install it; or wait for a sale
(every 2-3 months) and buy a newer faster, higher resolution model with a
2,000 page toner cartridge included for less than the cost of a full load toner.


Chuckle. Yeah, that's about it. Next purchase, I suggest HP LaserJet
printers. They have their own collection of problems, but parts and
refills are commonly available and cheap. The printer cannibals sell
used parts and assemblies fairly cheap on eBay. Also, expertise is
more easily found:
http://www.fixyourownprinter.com
My favorite printer of the week is the HP 2300DN or DTN at between $90
to $220 used depending on condition and options. Favorite feature is
double sided (duplex) printing.

Geoff.


--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #46  
Old October 4th 12, 07:19 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
Jeff Liebermann
external usenet poster
 
Posts: 25
Default Using mobile phone as an internet radio

On Wed, 03 Oct 2012 19:42:21 -0400, "
wrote:

My 39YO HP45 still works but the power switch is too flaky to be usable.


I collect old HP LED type calculators. The HP 45 is well worth fixing
and using.

The switches tend to fail due to dirt accumulation and/or wearing a
grove into the PCB contact area from overuse. I've repaired both
problems.
http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv018.cgi?read=131014
This is the dirt problem:
http://i45.photobucket.com/albums/f96/geoff_q/gunk.jpg
I couldn't find a photo of a grove worn in the contacts. I've been
quite successful with just cleaning the switch area. I've also
repaired missing gold problems with gold leaf. It was difficult,
required a microscope, a steady hand, no air movement, and
considerable patience.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #47  
Old October 4th 12, 08:57 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
George Herold
external usenet poster
 
Posts: 7
Default Using mobile phone as an internet radio

On Oct 4, 12:43*pm, Jeff Liebermann wrote:
On Thu, 04 Oct 2012 10:03:21 -0400, Phil Hobbs





wrote:
On 10/03/2012 09:41 PM, Jeff Liebermann wrote:
On Wed, 03 Oct 2012 10:32:57 -0400, Phil Hobbs
*wrote:


I don't know of any data that supports this common idea, but I'd be
interested in reading about it if anybody's actually done the experiment
carefully.


It's an accelerated life test. *The deration curve of the incandescent
light bulb is well known and assumed to be
* *(Vapplied/Vdesign)^-12 to ^-16 * Life at design voltage
http://www.welchallyn.com/documents/Lighting/OEM_Halogen_Lighting/MC3....
See Fig 5 on Pg 5 for the graph. *Nobody wants to wait 1000 hours for
a bulb to blow. *So, they increase the applied voltage, which
dramatically decreases the lifetime down to reasonable test times.
Using a rack of bulbs, they obtain an average (or median) lifetime at
the higher voltage. *Then, they work backwards on the curve to
estimate what it would be at the design voltage.


You can't run an accelerated life test when the exponent isn't known
more accurately than 12 to 16.


True, but I believe that's the range expected from different types of
light bulbs (nitrogen filled, halogen, vaccuum), and not the range
expected for a given device. *I suspect that more accurate exponent
value could be empirically determined for a given device, and later
used only for that device.

Yep. *As I understand it (possible wrong), AC filaments break in the
middle, mostly from vibration flexing.


I don't think so, because there's no mechanism for that, as I said. *The
wire is fully annealed at all times, so there's no possibility of
progressive fatigue failure.


http://en.wikipedia.org/wiki/Incandescent_light_bulb#Reducing_filamen...
* *One of the problems of the standard electric light bulb is
* *evaporation of the filament. Small variations in resistivity
* *along the filament cause "hot spots" to form at points of
* *higher resistivity; a variation of diameter of only 1% will
* *cause a 25% reduction in service life. The hot spots evaporate
* *faster than the rest of the filament, increasing resistance
* *at that point a positive feedback that ends in the familiar
* *tiny gap in an otherwise healthy-looking filament.

Note the photo of the filament with a break in the middle. *When I was
quite young, I would break burnt out AC light bulbs to see what was
inside. *If the filament was intact, the break was always somewhere
near the middle. *If a piece broke off, one end of the broken piece
was usually near the middle. *In later years, I would look at the
remains of DC panel lights (usually type 47 for old Motorola radios)
and noted that the breaks were always near the supporting terminals,
probably due to metal migration.

I suspect that the notion that cycling is hard on bulbs comes from the
way that the bulb often fails at turn-on, when the thinnest hot spot
vapourizes before the rest of the filament has a chance to come up to
temperature and reduce the inrush current.


Yep. *See my comments on the relatively high failure rate on the
40watt theater marquee lamps due to cycling. *The same lamps in the
lobby and foyer were not cycled and seemed to last forever.


I was actually disagreeing with you. *There are lots of possible reasons
for the marquee lights failing prematurely. *I'm not a tungsten expert
myself, so I'd be very interested in seeing actual data that shows a
dramatic shortening of life due to cycling. *I'm not saying it's
impossible, just that I haven't seen any such data.


So much for my anecdotal data. *My theater marquee experience was in
about 1966. *The theater actually did keep records so that they could
stock enough replacement bulbs, but I don't have copies of any of
that.

I tried Googling for similar repetative on-off tests and didn't find
anything. *If I have time, I'll try again. *I must admit that the lack
of test data does look suspicious. *Perhaps sending the idea to
Mythbusters and have them runs a test?

The filament isn't tungsten-plated, it's pure tungsten or a low alloy.
The brightness drop comes from tungsten condensing on the envelope.


Oops. *I thought it was plated.

And the connecting wire isn't plain steel, it's generally Dumet,
http://www.jlcelectromet.com/dumetwire.htm


which is a 42% Ni steel with OFHC copper or nickel plating.


You're making a lot of that up. *I'd still like to see
carefully-collected data.


No, not fabricated. *It's my reliance on my memory in an area that I'm
not familiar with. *I tried Googling for the wire used, couldn't find
much, and made a bad guess. *The plating came from somehow getting
thorium coated tungsten wire used in vacuum tubes mixed up with light
bulbs. *Sorry for the errors and muddle.

Cheers
Phil Hobbs


--
Jeff Liebermann * *
150 Felker St #D * *http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann * * AE6KS * *831-336-2558- Hide quoted text -

- Show quoted text -


Hi Jeff, Phil. First I know nothing about incandescent bulbs.
But how about this as a model of why turning bulbs on and off might
cause them to fail sooner.

1.) I think we all observe that bulbs tend to blow when you turn them
on.
(unless you knock the lamp over or something.)

2.) I assume that the failure is mostly due to the thinner ‘hot spots’
on the filament. Thinner regions heat up faster (higher resistance
with equal current).

3.) Now even if the thinner region doesn’t blow, it still gets hotter
and loses a bit more tungsten than the rest of the filament. (For
that small amount of time that it’s turning on.) But still this means
that turning on the bulb causes the thin region to become a bit
thinner.

And that’s it. Repeated on and off means that the thin region has a
higher average temperature than the thick part of the filament. It
evaporates faster and fails sooner.

George H.
  #48  
Old October 4th 12, 10:28 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
Phil Hobbs
external usenet poster
 
Posts: 15
Default Using mobile phone as an internet radio

On 10/04/2012 02:57 PM, George Herold wrote:
On Oct 4, 12:43 pm, Jeff wrote:
On Thu, 04 Oct 2012 10:03:21 -0400, Phil Hobbs





wrote:
On 10/03/2012 09:41 PM, Jeff Liebermann wrote:
On Wed, 03 Oct 2012 10:32:57 -0400, Phil Hobbs
wrote:


I don't know of any data that supports this common idea, but I'd be
interested in reading about it if anybody's actually done the experiment
carefully.


It's an accelerated life test. The deration curve of the incandescent
light bulb is well known and assumed to be
(Vapplied/Vdesign)^-12 to ^-16 * Life at design voltage
http://www.welchallyn.com/documents/Lighting/OEM_Halogen_Lighting/MC3...
See Fig 5 on Pg 5 for the graph. Nobody wants to wait 1000 hours for
a bulb to blow. So, they increase the applied voltage, which
dramatically decreases the lifetime down to reasonable test times.
Using a rack of bulbs, they obtain an average (or median) lifetime at
the higher voltage. Then, they work backwards on the curve to
estimate what it would be at the design voltage.


You can't run an accelerated life test when the exponent isn't known
more accurately than 12 to 16.


True, but I believe that's the range expected from different types of
light bulbs (nitrogen filled, halogen, vaccuum), and not the range
expected for a given device. I suspect that more accurate exponent
value could be empirically determined for a given device, and later
used only for that device.

Yep. As I understand it (possible wrong), AC filaments break in the
middle, mostly from vibration flexing.


I don't think so, because there's no mechanism for that, as I said. The
wire is fully annealed at all times, so there's no possibility of
progressive fatigue failure.


http://en.wikipedia.org/wiki/Incandescent_light_bulb#Reducing_filamen...
One of the problems of the standard electric light bulb is
evaporation of the filament. Small variations in resistivity
along the filament cause "hot spots" to form at points of
higher resistivity; a variation of diameter of only 1% will
cause a 25% reduction in service life. The hot spots evaporate
faster than the rest of the filament, increasing resistance
at that point a positive feedback that ends in the familiar
tiny gap in an otherwise healthy-looking filament.

Note the photo of the filament with a break in the middle. When I was
quite young, I would break burnt out AC light bulbs to see what was
inside. If the filament was intact, the break was always somewhere
near the middle. If a piece broke off, one end of the broken piece
was usually near the middle. In later years, I would look at the
remains of DC panel lights (usually type 47 for old Motorola radios)
and noted that the breaks were always near the supporting terminals,
probably due to metal migration.

I suspect that the notion that cycling is hard on bulbs comes from the
way that the bulb often fails at turn-on, when the thinnest hot spot
vapourizes before the rest of the filament has a chance to come up to
temperature and reduce the inrush current.


Yep. See my comments on the relatively high failure rate on the
40watt theater marquee lamps due to cycling. The same lamps in the
lobby and foyer were not cycled and seemed to last forever.


I was actually disagreeing with you. There are lots of possible reasons
for the marquee lights failing prematurely. I'm not a tungsten expert
myself, so I'd be very interested in seeing actual data that shows a
dramatic shortening of life due to cycling. I'm not saying it's
impossible, just that I haven't seen any such data.


So much for my anecdotal data. My theater marquee experience was in
about 1966. The theater actually did keep records so that they could
stock enough replacement bulbs, but I don't have copies of any of
that.

I tried Googling for similar repetative on-off tests and didn't find
anything. If I have time, I'll try again. I must admit that the lack
of test data does look suspicious. Perhaps sending the idea to
Mythbusters and have them runs a test?

The filament isn't tungsten-plated, it's pure tungsten or a low alloy.
The brightness drop comes from tungsten condensing on the envelope.


Oops. I thought it was plated.

And the connecting wire isn't plain steel, it's generally Dumet,
http://www.jlcelectromet.com/dumetwire.htm


which is a 42% Ni steel with OFHC copper or nickel plating.


You're making a lot of that up. I'd still like to see
carefully-collected data.


No, not fabricated. It's my reliance on my memory in an area that I'm
not familiar with. I tried Googling for the wire used, couldn't find
much, and made a bad guess. The plating came from somehow getting
thorium coated tungsten wire used in vacuum tubes mixed up with light
bulbs. Sorry for the errors and muddle.

Cheers
Phil Hobbs


--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558- Hide quoted text -

- Show quoted text -


Hi Jeff, Phil. First I know nothing about incandescent bulbs.
But how about this as a model of why turning bulbs on and off might
cause them to fail sooner.

1.) I think we all observe that bulbs tend to blow when you turn them
on.
(unless you knock the lamp over or something.)

2.) I assume that the failure is mostly due to the thinner ‘hot spots’
on the filament. Thinner regions heat up faster (higher resistance
with equal current).

3.) Now even if the thinner region doesn’t blow, it still gets hotter
and loses a bit more tungsten than the rest of the filament. (For
that small amount of time that it’s turning on.) But still this means
that turning on the bulb causes the thin region to become a bit
thinner.

And that’s it. Repeated on and off means that the thin region has a
higher average temperature than the thick part of the filament. It
evaporates faster and fails sooner.

George H.


If the effect is real, that sounds like a good candidate for a
mechanism. Certainly you'd expect that to be important right near the
end of the bulb's life, so maybe it's important throughout.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net
  #49  
Old October 4th 12, 11:05 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
Jeff Liebermann
external usenet poster
 
Posts: 25
Default Using mobile phone as an internet radio

On Thu, 4 Oct 2012 11:57:21 -0700 (PDT), George Herold
wrote:

Hi Jeff, Phil. First I know nothing about incandescent bulbs.


I'm still learning (mostly from my mistakes).

I blundered across this video on tungsten filaments.
http://www.youtube.com/watch?v=DIGqBb3iZPo 3:38
While it doesn't touch any of the issues previously mentioned, it does
include some interesting info on how the filament is made and its
structure.

--
Jeff Liebermann
150 Felker St #D
http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
  #50  
Old October 4th 12, 11:15 PM posted to uk.tech.digital-tv,24hoursupport.helpdesk,uk.telecom.mobile,sci.electronics.basics,sci.electronics.repair
Tom Biasi
external usenet poster
 
Posts: 4
Default Using mobile phone as an internet radio

On 10/3/2012 2:01 AM, MikeS wrote:

Using anything shortens it's working life.


Seems to go against the whole ethos of exercising. Never get out of bed and
live forever ...


If you were an android that may be true.
 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
DVD to mobile phone? Paul D.Smith[_2_] UK digital tv 15 June 16th 10 09:36 AM
Mobile phone projectors Brian Gaff UK digital tv 9 July 24th 09 10:11 AM
Now use Skype from your mobile phone [email protected] High definition TV 1 November 17th 06 12:50 AM
Where is a mobile phone :-) PEO from ITALY UK digital tv 0 October 27th 06 05:12 PM
AD: Mobile GPS, Mobile Satellite Internet, Flat Panel DBS Antennas, Used DirecTV and Dish Network and much much more! Satellite dbs 0 November 8th 03 11:14 PM


All times are GMT +1. The time now is 11:54 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2021, Jelsoft Enterprises Ltd.
Copyright ©2004-2021 HomeCinemaBanter.
The comments are property of their posters.