Using mobile phone as an internet radio

On 2012-10-12, Michael A. Terrell wrote:

The projector bulbs in the old RCA TP66 film chain were mounted in a
vertical line. If you used the bottom lamp, and let it switch the to
spare on top, they had a short life of a little over 20 hours. If you
ran the top lamp, with the spare at the bottom, the life was over five
times longer. The projector used a motorized track, with a relay in
series with the filament. When the filament opened, the relay dropped
out and turned on the motor. In either position, it would run to look
for the other bulb when the one in use failed. I would pull the bad
lamp and move the good lamp to the top at the next film change, then put
the new lamp in the bottom socket. I averaged over 130 hours per lamp,
that way.

Are you saying that 20 hours resting above the working lamp knocked 100
hours off the lifeime? in other words, I
f you did the opposite did that reduce the
life of every lamp to 20 hours.

Or was it 130 hours above the working lamp that reduced the life of
the spare by 100 hours?

It seems surprising that the lamps were so readily damaged by
environmental heat


--
⚂⚃ 100% natural

--- news://freenews.netfront.net/ - complaints: ---

Jasen Betts wrote:

On 2012-10-12, Michael A. Terrell wrote:

The projector bulbs in the old RCA TP66 film chain were mounted in a
vertical line. If you used the bottom lamp, and let it switch the to
spare on top, they had a short life of a little over 20 hours. If you
ran the top lamp, with the spare at the bottom, the life was over five
times longer. The projector used a motorized track, with a relay in
series with the filament. When the filament opened, the relay dropped
out and turned on the motor. In either position, it would run to look
for the other bulb when the one in use failed. I would pull the bad
lamp and move the good lamp to the top at the next film change, then put
the new lamp in the bottom socket. I averaged over 130 hours per lamp,
that way.

Are you saying that 20 hours resting above the working lamp knocked 100
hours off the lifeime? In other words, if you did the opposite did that
reduce the life of every lamp to 20 hours.


It did it to three in a row. We were on the air with film for about
75 hours a week, on a two projector film chain. We were issued six
lamps for three months, then had to find other sources.


Or was it 130 hours above the working lamp that reduced the life of
the spare by 100 hours?

It seems surprising that the lamps were so readily damaged by
environmental heat


They were in a steel & aluminum box with little ventilation, and in a
non air conditioned environment. the control room could reach 95
degrees on summer afternoons. The glass would distort & sag before the
filament opened. The projectors were run off a motorized Sola
Adjust-A-Volt to keep the line voltage at 120 V. It was used instead of
a CVT, because of the cap run motors in the projectors.


You couldn't leave the doors open, because wild animals would come
into the building. The only thing that couldn't were the huge buffalo
that wouldn't fit through the door.

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

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.

Just butting in to comment that you've got the failure mechanism spot
on!

It's impossible to draw tungsten filament wire with a perfectly
constant diameter and since the cold resistance is about a tenth of
its hot resistance value, the initial switch on surge heats the ever
so slightly thinner parts more (raising the resistance ever so
slightly more, which magnifies the hot spot effect).

From brand new, the hot spot effect is insignificant but becomes just
slightly less insignificant with each switch on surge event. The
deterioration process accelerates as the switching count goes up,
eventually culminating in a final flash of expiration on that fateful
final switch on event.

Although a filament might just manage to survive the fatal last
switch on surge and choose to fail anywhere from minutes to hours
later, this is quite uncommon.

The life rating by the manufaturer does take account of the typical
on/off switching usage. Such 'Thousand Hour' rated lamps, if left
switched on could easily clock up several thousand hours of service
before failing.
--
Regards, J B Good

On Fri, 05 Oct 2012 11:20:32 +0100, Roderick Stewart
wrote:

In article de99517e-e5e1-4f9d-91e0-
, George Herold wrote:
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.

Won't a thin region of a lamp filament have a higher temperature than
the rest of it all the time, not just when the lamp is turning on?

Yes, but the effect is just too slight once the whole filament has
warmed up. The thinner parts might run a a degree or two hotter in a
new lamp but this difference will increase with age and the mounting
number of switch on events during its service life.
--
Regards, J B Good

On Mon, 8 Oct 2012 06:27:05 -0700 (PDT), George Herold
wrote:

On Oct 8, 12:00*am, Jeff Liebermann wrote:
On 6 Oct 2012 23:31:51 GMT, Jasen Betts wrote:

yeah, it would be a good project for the mythbusters, I'd love to see
a slow motion film of an incandescent lamp failing at turn-on.
but could they affor do dedicate their fast camera for long enough.

Due to the apparently lack of data and my curiosity, I was thinking of
throwing together a crude experiment. *Two lamp bases, two 40 watt
clear envelope incandescent lamps, two SSS (solid state switches), and
some kind of pulse generator. *30 seconds on should be enough to get
the filament hot enough for sublimation. *30 seconds off should be
enough for it to cool down for a cold start (I need to check this with
an IR thermometer).

However, I have no intention of running this test for 1000+ hours.
Instead, an accelerated life test can be done with higher than normal
voltages.
http://www.welchallyn.com/documents/Lighting/OEM_Halogen_Lighting/MC3...
For halogen bulbs, they use:
* Life = (Vdesign / Vapplied)^12.0 * Life at design voltage
For a 1000 hr lamp running at 120% of the rated voltage, the life
might be:
* life = (1/1.2)^12 * 1000 = 112 hrs
which is more reasonable for my tinkering and for Mythbusters. *With
power cycling, the life will be even less. *I should have a Variac
somewhere in my junk pile.

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

Hi SEB. Well I sent an email to Don klipstein on this topic. And
have permission to copy his reply.

from Don K. below

My apologies - I have been off Usenet for a little over a year.

Hi Don, I was wondering (out loud) if you still lurk on the
sci.electronics.basic usernet forum?
(So I figured I'd just drop you an email.)

We have a question about the aging of incandescent bulbs from being
turned on and off. You seem like quite a lamp expert and I was
wondering if you've ever come across any real data on the subject.

As for real data on effect of switching causing wear on
incandescents:

I know some data.

1: It is true that incandescents often failon cold starts. However,
I
know a mechanism where an aging incandescent becomes unable to
survive
a cold start a little before it becomes unable to survive continuous
operation.

I explain this in: http://donklipstein.com/bulb1.html#how
And: http://donklipstein.com/bulb1.html#wbt

2: In incandescent traffic signals, the bulbs for yellow last longer
than
for red and green. So even after being switched on and off about a
million times, on-time is still a significant factor in life
expectancy.

However, traffic signal bulbs have a more vibration-resistant
filament
than standard incandescents.

3: Flashing and chasing marquee lights used to be incandescent until
cold cathode CFLs became economically available. Cold cathode CFLs
are special CFLs that are dimmable and blinkable, and flashing them
does not detract from their life. However, their efficiency is less
than that of hot cathode CFLs. Some marquees still use
incandescents.

4: I did an experiment to check for voltage drop in one of those
now-hard-to-get thermistor-type life-extending "buttons" to attach
to the tip of the base of an incandescent. The device claimed to
double the life of the bulb. I found enough voltage drop to account
for 50-60% life extension. Light output was reduced 13%, and power
consumption of the combo of the bulb and the thermistor was only
2.05%
less than that of a bulb connected directly to the line.

5: In my experience, incandescent holiday lights that blink last
longer
than those that don't. However, most of my experience is with low
voltage bulbs whose short filaments are probably sturdier.

6: Some incandescents make an audible "ping" when switched on.
However,
deflection of the filament does not necessarily strain the filament
past its "endurance limit" - the threshold of causing metal fatigue.

7: Some railroad crossing signals have a set-up where bulbs have a
resistor added in series with them for the first half second or so
that they are on. However, this may be done because of how serious
the problem is widely said to be, and how serious it actually is
appears
to me to be much less.

8: One of my friends had a bathroom fixture with a high wattage bulb
that
was constantly run dimmed by a dimmer. He experienced little gain
in
life extension. Since his bulbs significantly audibly buzzed, I
suspect
his filaments resonated at the power line frequency or one of the
power
line frequency's lower harmonics.

9: My mother had some incandescent nightlights that had diodes in
them
to significantly dim the bulbs - which should have made the bulbs
last
for decades. However, they did not.
One thing I noticed: These 4-watt bulbs had extremely thin
filaments,
and with a diode and therefore being off half the time 60 times a
second, their temperature varied greatly up and down 60 times a
second.
I could see that from rolling my eyes up-and-down while looking at
them.
Maybe the filaments at times resonated at the power line frequency
or
a lower harmonic thereof. That could easily produce sound too weak
to
hear from more than a couple inches away, because such low wattage
120V
incandescents have a vacuum rather than a gas fill.

Or, maybe those bulbs do not do well with DC due to high voltage,
vacuum, and the ends of the filament being close to each other.
Please see: http://donklipstein.com/bulb1.html#dc

======================

Overall, I am seeing generally that cold starts are not nearly as
bad as many say they are, but in a few bulbs they can be. The data
appears to me to be majority in favor of "little to generally no
problem from cold starts", but it is incomplete.

I would also suggest reading:

http://donklipstein.com/ltrouble.html#i

====================

Hope this helps!

- Don Klipstein )

I feel it's worth pointing out that this filament thinning effect
gets worse with higher voltage (longer) filaments. The US standard
lamp voltage is 117v which makes such switch on induced failure less
obvious compared to the UK and European case (typically 240v and 220v
supplies).

If you're consideringfitting those horrible ceiling downlighting
fittings using Halogen GU lamps, I'd suggest you avoid the 240v lamps
else you'll forever be having to replace them on an all too frequent
schedule.

When we had the downstairs shower room reffited a few years back, the
missus, much against my better judgment, decided to have ceiling
downlighters fitted. I made sure to specify low voltage "Transformer"
fed lamps and, thus far, haven't had to replace any lamps (four in
all).

Observing the half second or so 'Fade up' on switch on confirms why
they've survived the switching cycles over the years and I suspect
they're as likely to go pop mid use as during a switch on 'surge' when
they finally do succumb to old age.
--
Regards, J B Good

"Rocky" wrote in message
...

"William Sommerwerck" wrote in message
...
Using anything shortens its working life.

I can vouch for the remark made but I can give you more details too:

I use smartphones, tablets and laptops to listen to internet radio all
the
time and I've only had one device that suffered because of that. What
happened to that particular device is the WiFi quit working and it
doesn't
even work after a factory reset.

Who knows why the WiFi quit? The radio could have failed simply because
the
chip went bad.

HP has had problems with the radios in some of its notebooks.

Yes, I've heard that and I've even seen one person that no longer has WiFi
on their HP notebook but they claimed it was the switch itself that quit
working so I try not to use the hardware WiFi switch on an HP notebook.

Me, I've had a power plug fail on an HP ZD7000 notebook and that was
common for that particular notebook.

I've also had a DVD fail on an HP DV8000 notebook but when the second DVD
failed too I went back to the first DVD and it has been working fine since
then. I doubt if I'll ever figure that one out unless if it was a problem
with the connector.

Other than that, I've seen a lot of videos on youtube with problematic HPs
where if it isn't the WiFi that goes out it is the video. Case in point:

HP 's Worst Laptop Ever - Pavilion ZD8000 -
http://www.youtube.com/watch?v=2stqQtQePcM&hd=1

Oddly enough I skipped getting the HP ZD8000 because I went from an HP
ZD7000 to the HP DV8000 where the ZD8000 looks more like the ZD7000 than
the DV8000.

FYI the only device I had that lost the WiFi was a Pharos Traveler 137
that I got real cheap when a place was getting rid of them so I wasn't too
upset when the WiFi quit on that.
http://www.pharosgps.com/products/proddetail.asp?prod=001_PTL137_8.00

FYI I recently copied a bunch of songs up to a micro SDHC card and I can
still use bluetooth A2DP to play those songs through the speakers connected
to a laptop with bluetooth. So that means even though the WiFi quit working
on the device mentioned above the bluetooth still seems to work OK so they
must not be using the same transmitter or same receiver.

http://www.mobileburn.com/definition.jsp?term=A2DP

Rocky

On Sun, 21 Oct 2012 10:13:46 -0500, "Rocky" wrote:


"Rocky" wrote in message
m...

"William Sommerwerck" wrote in message
...
Using anything shortens its working life.

I can vouch for the remark made but I can give you more details too:

I use smartphones, tablets and laptops to listen to internet radio all
the
time and I've only had one device that suffered because of that. What
happened to that particular device is the WiFi quit working and it
doesn't
even work after a factory reset.

Who knows why the WiFi quit? The radio could have failed simply because
the
chip went bad.

HP has had problems with the radios in some of its notebooks.

Yes, I've heard that and I've even seen one person that no longer has WiFi
on their HP notebook but they claimed it was the switch itself that quit
working so I try not to use the hardware WiFi switch on an HP notebook.

Me, I've had a power plug fail on an HP ZD7000 notebook and that was
common for that particular notebook.

I've also had a DVD fail on an HP DV8000 notebook but when the second DVD
failed too I went back to the first DVD and it has been working fine since
then. I doubt if I'll ever figure that one out unless if it was a problem
with the connector.

Other than that, I've seen a lot of videos on youtube with problematic HPs
where if it isn't the WiFi that goes out it is the video. Case in point:

HP 's Worst Laptop Ever - Pavilion ZD8000 -
http://www.youtube.com/watch?v=2stqQtQePcM&hd=1

Oddly enough I skipped getting the HP ZD8000 because I went from an HP
ZD7000 to the HP DV8000 where the ZD8000 looks more like the ZD7000 than
the DV8000.

FYI the only device I had that lost the WiFi was a Pharos Traveler 137
that I got real cheap when a place was getting rid of them so I wasn't too
upset when the WiFi quit on that.
http://www.pharosgps.com/products/proddetail.asp?prod=001_PTL137_8.00

FYI I recently copied a bunch of songs up to a micro SDHC card and I can
still use bluetooth A2DP to play those songs through the speakers connected
to a laptop with bluetooth. So that means even though the WiFi quit working
on the device mentioned above the bluetooth still seems to work OK so they
must not be using the same transmitter or same receiver.

They don't. The antennas are separate, even.

http://www.mobileburn.com/definition.jsp?term=A2DP