Using mobile phone as an internet radio

On 2012-10-05, George Herold wrote:

I've no problem with your marquee story. Sometimes folk-tales about
rocks falling from the sky are correct.
The data point I offer to Phil is that bulbs fail when you turn them
on. I see no reason why that can't be 'played backwards'. There most
be some GE, Philips, (other) report that documents turn on failure.

I recall a few yeas back someone had long-life bulbs with an NTC
series resistor built into the base.
Old toob tellys always had an NTC in series with the filament supply.




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On 2012-10-05, Roderick Stewart wrote:
In article de99517e-e5e1-4f9d-91e0-
, George Herold wrote:
And thatÂ’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?

It will, but due to the thermal coefficient of resistance of tungsten
(most other metals are similar) the heating will be even greater when the
filament heats from cold. The hot spot gains resistance faster, so it
drops a greater voltage while the rest of the filament is still cold.


disclaimer: figures made up to illustrate the point

assume a constant-voltage supply compute the power disipated by he
thin spot (middle resistor) in each case


cold ----[100]---[1]---[100]---

hot ----[1000]-[12]-[1000]----

during warm-up thin spot warms up fastest.

start ---[200]---[3]---[200]---



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.

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On 2012-10-06, MB wrote:

The Americans do seem generally to be used to sending a lot by courier
when we would just put in the post. Tending to happen in the UK also
even though the Royal Mail / Parcelforce often give a better service and
of course do not charge extra to send further. There has been a big
campaign in the North of Scotland about companies charging extra for
many postcode areas.

Digi-Key sent me (in NZ) a postcard by royal mail (from UK) the other day.
if it's still in the waste bassket on monday it'll check to see if it's a
preferred spelling thing (eg: "catalog" vs "catalogue") or perhaps it was
just cheaper to do it that way.

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Jasen Betts wrote:

Old toob tellys always had an NTC in series with the filament supply.


Not in the US.

On 2012-10-06, Geoffrey S. Mendelson wrote:
Phil Hobbs wrote:

Several years ago the USPS restructured their rates for mail outside of the
US. They dropped surface mail, replacing it with an air mail system that
takes almost as long. I have had packages take 6 weeks to arrive here airmail
from the US.

They did a survey of prices of the courier services, and simply charge 1/2
of what the courier services do. If you want registered mail, they charge
another $12 or so for it.

Compare that to China which charges a few dollars to send a package, and
another dollar or so for registered mail. Or the UK (and the rest of the
EU) that charge about $5 for postage and registered mail.

Chinas international mail is heavily subsided. hearsay I've heard that
it's so heavilty subsidised that in some cases they pay the sender
/hearsay. while doing the same in the USA would probably help small
exporters (and therefore the balance of payments) I can't see the
republican party getting behind subsidising a "state run monopoly".

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Jasen Betts wrote:
Chinas international mail is heavily subsided. hearsay I've heard that
it's so heavilty subsidised that in some cases they pay the sender
/hearsay. while doing the same in the USA would probably help small
exporters (and therefore the balance of payments) I can't see the
republican party getting behind subsidising a "state run monopoly".

Isn't the USPS already a state run monopoly which is subsidised?

http://en.wikipedia.org/wiki/US_Postal_Service

Note that it says that the USPS has not DIRECTLY received taxpayer funds
since the 1980's.

Geoff.

--
Geoffrey S. Mendelson, N3OWJ/4X1GM/KBUH7245/KBUW5379
"Owning a smartphone: Technology's equivalent to learning to play
chopsticks on the piano as a child and thinking you're a musician."
(sent to me by a friend)

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/MC3544HPX_Catalog_2_11_09.pdf
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 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

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 )

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

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

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.

That means for my proposed test comparing a 50% duty cycle flashing
light bulb, with one that is on continuously, the continuous light
bulb will burn out first. That's the opposite of what I saw with the
theater marquee bulbs. Now, I'm really tempted to run the experiment.

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

Jeff Liebermann wrote:

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

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

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.

That means for my proposed test comparing a 50% duty cycle flashing
light bulb, with one that is on continuously, the continuous light
bulb will burn out first. That's the opposite of what I saw with the
theater marquee bulbs. Now, I'm really tempted to run the experiment.


Was there any vibration in that theater marquee?