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'[EE]: Bulb Life'
2001\07\03@053004 by Roman Black

flavicon
face
I have been reading the bulb-life discussion,
specifically regarding the doubling of the
bulbs life expectancy from dropping the AC voltage
a few percent.

I just want to state that you can get many times
this effect from adding a series resistor, which
drops the voltage as desired, BUT ALSO reduces the
start current of the cold filament. So if just
dropping the voltage 5% can give double the bulb
life, doing this with a series resistor can give
10x or more bulb life.

I measured a 240vac 60w bulb, at 60 ohms cold.
If you turn on the switch at the ac peak, this will
give 340v into a 60 ohm filament!

That is worst case power of 1927w,
Almost 2kW!!! No wonder they blow every ten weeks
or less, and I have "light bulbs" on most of my
shopping lists.

If you drop just 5% of running voltage with a
resistor, with a 60w bulb it needs about 50 ohms
series resistor. The bulb gets 5% less volts when
running and is almost as bright.

BUT! Now at cold start the worst case power in
the filament is almost a quarter of what it was,
and the number one cause of bulb death is virtually
eliminated. It's quite possible to get 10 years
or more from an incandescent bulb, maybe 20 or 30
times the "normal" life span.

I learned this from an old electrician when I was
an apprentice. He did this 5% trick on some of
the bulbs in very high places. And some bulbs
were so old they were almost black. :o)

What irks me is that the bulb manufacturers could
very easily add a 5% wire resistor into their filament
designs, and make bulbs that last almost forever.

They just rip us off in a cold calculated fashion
with products designed to last a few weeks!!
-Roman

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2001\07\03@080019 by Olin Lathrop

face picon face
> What irks me is that the bulb manufacturers could
> very easily add a 5% wire resistor into their filament
> designs, and make bulbs that last almost forever.

They are probably more concerned with efficiency.  Incandescent bulbs are
already hideously inefficient, and adding the resistor makes the overall
solution even more so.  Note that the efficiency goes down by much more than
the 5% of the power going to the resistor because the filament runs cooler
and therefore significantly less efficiently.

The manufacturers already make "long life" bulbs.  It appears that these use
beafier filaments that run a little cooler.  Note that the light output of
these bulbs is less than the normal ones at the same wattage.  In
otherwords, they traded efficiency for life, which is what you are doing
with the resistor.

The real cost of an incandescent bulb is the electricity it uses (work it
out, you may be surprised), so most of the time it is cheaper to use bulbs
with higher efficiency but shorter life.  Of course I'm talking about the
majority of cases where the bulb is easy to change and nothing catastrohpic
happens when it goes out occasionally, like in your house.

> They just rip us off in a cold calculated fashion
> with products designed to last a few weeks!!

I'm no fan of incandescent bulbs, but they certainly last more than "a few
weeks" around here.  We have 120V mains here instead of 240V.  Do the 240V
bulbs really last that much shorter or were you exaggerating a bit or do you
leave your lights on all the time?  Incandescent bulbs are inherently low
voltage high current devices, and making a good 240V bulb is going to be
harder than a good 120V bulb.

How about using two 120V bulbs in series?


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2001\07\03@081145 by Jinx

face picon face
> They just rip us off in a cold calculated fashion
> with products designed to last a few weeks!!
> Roman

Not me they don't. Not no more

Thanks again for your prodding to install resistors

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2001\07\03@081602 by Jinx

face picon face
> Do the 240V bulbs really last that much shorter or were
> you exaggerating a bit

They really do fizzle out with annoying regularity at 240V

> or do you leave your lights on all the time?

The ones I had trouble with were those that are on a lot of the
time - the longer they're on the thinner the filament gets and
more prone to turn-on blowout

> How about using two 120V bulbs in series?

Something I considered, as 120V filaments are thicker, but two
bulbs isn't always practical. I may yet look into it, as one or two
fittings could be changed fairly easily

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2001\07\03@082703 by Bob Ammerman

picon face
>
> I'm no fan of incandescent bulbs, but they certainly last more than "a few
> weeks" around here.  We have 120V mains here instead of 240V.  Do the 240V
> bulbs really last that much shorter or were you exaggerating a bit or do
you
> leave your lights on all the time?  Incandescent bulbs are inherently low
> voltage high current devices, and making a good 240V bulb is going to be
> harder than a good 120V bulb.
>
> How about using two 120V bulbs in series?
>
>
> ********************************************************************
> Olin Lathrop, embedded systems consultant in Littleton Massachusetts

If two 120V bulbs in series works well, then why don't the manufacturers put
two 120V filaments in series in one envelope?

Or just create one filament, with the same wire, but twice as long?

Bob Ammerman
RAm Systems
(contract development of high performance, high function, low-level
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2001\07\03@093222 by Spehro Pefhany

picon face
At 08:25 AM 7/3/01 -0400, you wrote:
>
>If two 120V bulbs in series works well, then why don't the manufacturers put
>two 120V filaments in series in one envelope?

Cooler running filaments produce less (and redder) light per watt.
Ignoring the costs of changing them, electricity used is more expensive
than the actual cost of the bulb, maybe by 10:1 or 5:1, depending on
what you pay per kWH, from what I've seen. So, you'll get less light
per $ with a longer lasting bulb.

>Or just create one filament, with the same wire, but twice as long?

Obviously it isn't all that hard, they do have light bulbs in Europe. ;-)

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2001\07\03@094830 by Roman Black

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face
Olin Lathrop wrote:
>
> > What irks me is that the bulb manufacturers could
> > very easily add a 5% wire resistor into their filament
> > designs, and make bulbs that last almost forever.

> They are probably more concerned with efficiency.  Incandescent bulbs are
> already hideously inefficient, and adding the resistor makes the overall

As a businessman and small manufacturer I don't
think efficiency is an issue. If you know you sell
100k+ bulbs each month to a country why would you
make changes that reduced that figure?? It's profits
first, reliability and morality second.


> I'm no fan of incandescent bulbs, but they certainly last more than "a few
> weeks" around here.  We have 120V mains here instead of 240V.  Do the 240V
> bulbs really last that much shorter or were you exaggerating a bit or do you
> leave your lights on all the time?  Incandescent bulbs are inherently low
> voltage high current devices, and making a good 240V bulb is going to be
> harder than a good 120V bulb.
>
> How about using two 120V bulbs in series?


Yep the 240v bulbs really are that bad, see my calcs
for the worst case cold startup power and compare to
your calcs for 120v bulbs. Enormous difference. The
problem is not with leaving them on, it's cold starting,
every few weeks you switch the light on and it goes
"pop" and another $2 down the drain.

Using 2x 120v bulbs in series sounds excellent for
so many reasons, but imagine the downside, they are
hard to find here, and you have to replace each bayonet
fitting with two bayonet fittings. The resistor works,
its cheap, problem solved.

I have also started using high efficiency compact
fluorescents (bulb replacements) but if you have ever
opened one of these they use a lot of small parts run
very close to their limits, again designed to last
a number of weeks and fail.

I suppose lighting companies don't want to make failure
proof lighting?? Sure seems that way.
-Roman

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2001\07\03@114530 by Olin Lathrop

face picon face
> If two 120V bulbs in series works well, then why don't the manufacturers
put
> two 120V filaments in series in one envelope?
>
> Or just create one filament, with the same wire, but twice as long?

First, I said this mostly to point out the absurdity of the situation.  But
to answer your question, you would end up with a bulb that is twice the
wattage.  That's fine if you want that much light in one place.  In other
words, a 200W 240V bulb should be able to last as long as a 100W 120V bulb.
But, if you want 100W of light, then a 100W 120V bulb is going to last
longer than a 100W 240V bulb.  If you are lighting an area with multiple
bulbs already, then using 120V bulbs wired in series in pairs should, in
theory, increase life.  In practise???

Personally, I use compact flourescents except where the bulb is turned on
and off frequently or is only on rarely.  Despite their higher purchase
price, compact flourscents are cheaper in the end because they use less
electricity.


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2001\07\03@120722 by Olin Lathrop

face picon face
> As a businessman and small manufacturer I don't
> think efficiency is an issue. If you know you sell
> 100k+ bulbs each month to a country why would you
> make changes that reduced that figure??

Because if you don't the competition will reduce it even more.

> I have also started using high efficiency compact
> fluorescents (bulb replacements) but if you have ever
> opened one of these they use a lot of small parts run
> very close to their limits, again designed to last
> a number of weeks and fail.

You know too much <g>.  I've used a bunch of these and so far have only
replaced two in several years.  One was a genuine failure because something
in the electronics broke.  The other got used a lot and eventually got
dimmer and didn't start right, but I think I got the rated life out of it.


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(978) 742-9014, .....olinKILLspamspam.....embedinc.com, http://www.embedinc.com

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2001\07\03@135536 by Douglas Butler

flavicon
face
> The manufacturers already make "long life" bulbs.  It appears
> that these use
> beafier filaments that run a little cooler.  Note that the
> light output of
> these bulbs is less than the normal ones at the same wattage.  In
> otherwords, they traded efficiency for life, which is what
> you are doing
> with the resistor.

Efficiency is strongly influenced by filament temperature.

Someone has a "Miser" series of lights that put out more visible light
per watt than regular bulbs.  They do this by polishing the filament
wire so that it is a poorer black body radiator.  To radiate the same
amount of power the filament has to get hotter than regular filament
would.  A hotter filament means you get more visible light and less
infra-red per watt.

This is good for efficiency but shortens the filament life due to the
tungsten evaporating faster.  It saves you money because you don't have
to buy as much electricity, but you have to change bulbs more often.
The electricity costs more than the bulbs.  In theory it is good for
you, good for the bulb company shareholders, but bad for the electric
company shareholders.  It is also a pain to keep chainging bulbs.

Sherpa Doug

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2001\07\03@192413 by Brian Kraut

picon face
Bulbs in series is a good method to increase bulb life.  It gets the startup
current way down so they don't blow when turned, and at the same time you are
not wasting your power in resistors.  Tube lights that they put in disco floors,
etc. are a bunch of series bulbs.  They are made so they almost never need to be
replaced.

Now if I could just find some 30 or 60V bulbs so I could rewire the twan and
four bulb fixtures in my house.

Olin Lathrop wrote:

{Quote hidden}

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2001\07\03@204209 by Tom Handley

picon face
  Olin, due to the power crisis here in the West, the two local
Portland, OR power companies are giving away coupons for free
compact flourescent bulbs. I've been using them for quite awhile
to not only cut down energy and get longer life, but to keep the
wasted heat down during the hot summer nights.

  - Tom

At 12:06 PM 7/3/01 -0400, Olin Lathrop wrote:
{Quote hidden}

------------------------------------------------------------------------
Tom Handley
New Age Communications
Since '75 before "New Age" and no one around here is waiting for UFOs ;-)

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2001\07\03@210150 by Jinx

face picon face
>    Olin, due to the power crisis here in the West, the two local
> Portland, OR power companies are giving away coupons for free
> compact flourescent bulbs. I've been using them for quite awhile
> to not only cut down energy and get longer life, but to keep the
> wasted heat down during the hot summer nights.
>
>    - Tom

How do you find the colour ? Bluey ? No different ? Something
you just get used to ?

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2001\07\03@210217 by Jinx

face picon face
>    Olin, due to the power crisis here in the West, the two local
> Portland, OR power companies are giving away coupons for free
> compact flourescent bulbs. I've been using them for quite awhile
> to not only cut down energy and get longer life, but to keep the
> wasted heat down during the hot summer nights.
>
>    - Tom

How do you find the colour ? Bluey ? "Cold" ? No different ?
Something you just get used to ?

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2001\07\03@211012 by Alexandre Domingos F. Souza

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face
>I have also started using high efficiency compact
>fluorescents (bulb replacements) but if you have ever
>opened one of these they use a lot of small parts run
>very close to their limits, again designed to last
>a number of weeks and fail.

       In Brazil they are beginning to be common. Around $10 for a lamp (!!!). Lasts a bit longer, but not much, than an incandescent one.


---8<---Corte aqui---8<----

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http://planeta.terra.com.br/lazer/pinball/

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2001\07\03@231819 by michael brown

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face
I've noticed that certain sockets in my house seem to cause bulbs to blow
more often.  It doesn't really seem to be just related to hours on.  I guess
it's possibly a combination of # of times switched and hours on.  I've heard
that a crummy (old) socket will blow bulbs more often, possibly from minute
glitches of high resistance from oxidation in the socket.  Maybe even the
extra physical stress exerted upon a new bulb when screwing it into a dirty
tight fitting socket causes some instant life loss from miniscule fractures
in the seal.

What really bugs me about the whole thing is that you can buy an LED that
puts out blinding light using milliwatts of power virtually forever, yet we
still think nothing of putting 100 watts into a bulb that has a relatively
short life span.  Is it possible that there is not a more efficient way?
Traffic lights are all becoming LED based, why cant I just buy a light
source built onto a pcboard that just screws into the socket.  With the
variety of LED colors available now, simulating a basically white light with
LED's shouldn't be that hard.  I realize the "quality of whiteness" might
not be ideal, but in your basement, shed, garage, or attic, who cares?

Michael Brown
Instant Net Solutions
http://www.KillerPCs.net

"In the land of the blind, he who has one eye is king"

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2001\07\04@002634 by Brandon Fosdick

flavicon
face
michael brown wrote:
> What really bugs me about the whole thing is that you can buy an LED that
> puts out blinding light using milliwatts of power virtually forever, yet we
> still think nothing of putting 100 watts into a bulb that has a relatively
> short life span.  Is it possible that there is not a more efficient way?
> Traffic lights are all becoming LED based, why cant I just buy a light
> source built onto a pcboard that just screws into the socket.  With the
> variety of LED colors available now, simulating a basically white light with
> LED's shouldn't be that hard.  I realize the "quality of whiteness" might
> not be ideal, but in your basement, shed, garage, or attic, who cares?

The Feb 2001 issue of Scientific American has an article that answers your
question. Unfortunately its not accessible from their web site. The short answer
is that its a cost/consumer acceptance problem. Its not yet cheap enough to
compete with conventional lighting in the home market, but its making headway in
commercial and utility applications, namely traffic lights. The article also
says that only 10% of the traffic lights in the US are LED based.

"The best commercial white LEDs now cost about 50 cents per lumen, compared with
a fraction of a penny per lumen for a typical incandescent bulb."

"...it may be a while before consumers accept LEDs, which cost more up front but
are cheaper over the span of a decade. As energy prices rise and the
consequences of global warming become more urgent, LEDs should become more
attractive."

It looks like its just a matter of time and consumer demand.

Why don't you design an led adapter for light sockets? Maybe use RGB LED's and a
PIC so you can change the color at will. I'd pay for that. Come to think of it,
if you don't do it, I will. :) How many LEDs does it take to equal a 60W light
bulb?

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2001\07\04@004927 by Charles Craft

picon face
www.magnavox.com/themes/led/index.html

Incredibly long life span and energy efficient - LED light bulbs are set to
brighten up your life

Who would have guessed that the once humble light bulb would become a 21st
Century technological wonder? The Luxeon LED family of light bulbs from
Philips now lasts 100 times longer, and is up to 4 times brighter than
today's standard incandescent bulbs. Not only this but we have managed to
break through a major technological barrier - recreating white light through
the power of the Light Emitting Diode.

{Original Message removed}

2001\07\04@015419 by Tom Messenger

flavicon
face
After all this talk to date on extending bulb life, etc., one simply has to
ask:

       "How many PIC'engineers does it take to change a light bulb?"

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2001\07\04@022543 by Spehro Pefhany

picon face
At 10:52 PM 7/3/01 -0700, you wrote:
>After all this talk to date on extending bulb life, etc., one simply has to
>ask:
>
>        "How many PIC'engineers does it take to change a light bulb?"

I get 74:

4 to argue that the light doesn't need to be changed
17 to investigate alternative LED and CF technologies
2 to complain about existing CF lamps
4 to go buy diodes and resistors to put in series
7 to make provocative political statements
3 to write PIC assembler code to ramp the light up
1 to write another version in C
2 to design the hardware and actually change the lamp
34 to try to reduce the assembler code by one instruction as a 'challenge'

Oh, and additional 3 P.E.s to argue that many of the other people are
not really engineers at all and one more to complain that the count is off.

Best regards,



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2001\07\04@032534 by David VanHorn

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face
At 02:28 AM 7/4/01 -0400, Spehro Pefhany wrote:
>At 10:52 PM 7/3/01 -0700, you wrote:
> >After all this talk to date on extending bulb life, etc., one simply has to
> >ask:
> >
> >        "How many PIC'engineers does it take to change a light bulb?"
>
>I get 74:
>
>4 to argue that the light doesn't need to be changed
>17 to investigate alternative LED and CF technologies
>2 to complain about existing CF lamps
>4 to go buy diodes and resistors to put in series
>7 to make provocative political statements
>3 to write PIC assembler code to ramp the light up
>1 to write another version in C
>2 to design the hardware and actually change the lamp
>34 to try to reduce the assembler code by one instruction as a 'challenge'

One more to recode it for the AVR, in half the space :)

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2001\07\04@082930 by Olin Lathrop

face picon face
[LED buld replacements]
> why cant I just buy a light
> source built onto a pcboard that just screws into the socket.

This is coming, but not quite yet.  The price would still be too high to
achieve the volumes necessary.  Note that LED lights are currently going
into applications where the cost of changing the bulb is very high, the
light gets switched on/off frequently, and the light is an indicator as
apposed to providing general illumination.

LEDs are getting cheaper and brighter.  Just give it time.


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2001\07\04@101328 by Bob Ammerman

picon face
> >After all this talk to date on extending bulb life, etc., one simply has
to
> >ask:
> >
> >        "How many PIC'engineers does it take to change a light bulb?"
>
> I get 74:
>
> 4 to argue that the light doesn't need to be changed
> 17 to investigate alternative LED and CF technologies
> 2 to complain about existing CF lamps
> 4 to go buy diodes and resistors to put in series
> 7 to make provocative political statements
> 3 to write PIC assembler code to ramp the light up
> 1 to write another version in C
> 2 to design the hardware and actually change the lamp
> 34 to try to reduce the assembler code by one instruction as a 'challenge'
>
> Oh, and additional 3 P.E.s to argue that many of the other people are
> not really engineers at all and one more to complain that the count is
off.

Don't forget the 6 who try to unsubscribble.

Ask Dmitry, he'll say 12.

Bob Ammerman
RAm Systems
(contract development of high performance, high function, low-level
software)

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2001\07\04@110018 by Spehro Pefhany

picon face
At 08:28 AM 7/4/01 -0400, you wrote:
>[LED buld replacements]
>> why cant I just buy a light
>> source built onto a pcboard that just screws into the socket.
>
>This is coming, but not quite yet.  The price would still be too high to
>achieve the volumes necessary.  Note that LED lights are currently going
>into applications where the cost of changing the bulb is very high, the
>light gets switched on/off frequently, and the light is an indicator as
>apposed to providing general illumination.

Also, as indicators, most of them are monochromatic (traffic signals, brake
lights on buses), where most of the energy from the incandescent is wasted
in the filter.

Best regards,
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2001\07\04@111025 by goflo

flavicon
face
Olin Lathrop wrote:
> ...
> Personally, I use compact flourescents except
> where the bulb is turned on and off frequently...

Is this hard on the light?  I've been using them for
7 years - They don't seem to last as long as claimed.
Phillips 15W compact fluorescents used in my desklamp
last about half the published lifetime.

regards, Jack

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2001\07\04@111028 by goflo

flavicon
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michael brown wrote:

>  ... why cant I just buy a light
> source built onto a pcboard that just screws into the socket ... ?

http://www.jademountain.com/light.html

Well, you can. These guys, for instance. Still very expensive
but the price is coming down.

regards, Jack

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2001\07\04@122417 by michael brown

flavicon
face
> michael brown wrote:
>
> >  ... why cant I just buy a light
> > source built onto a pcboard that just screws into the socket ... ?
>
> http://www.jademountain.com/light.html
>
> Well, you can. These guys, for instance. Still very expensive
> but the price is coming down.
>
> regards, Jack
Jack,

Pretty cool, only the equiv of a 25 watt bulb though.  Still, not too bad
for 12 LED's and 1.7 watts of power.  39.00 is a little steep, but it's
probably expensive getting the ship in the bottle so to speak.  Gotta have
that backward compatibility though.  So with 35 LED's, I could get some
decent light for 20 years, with about 5 watts input.  I like it. ;-D

michael

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2001\07\04@151751 by Michael C. Reid

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I count one.

He holds the bulb and the world revolves around him!!

---
> >        "How many PIC'engineers does it take to change a light bulb?"
>
>

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2001\07\04@152830 by Chris Carr

flavicon
face
> > >After all this talk to date on extending bulb life, etc., one simply
has
> to
> > >ask:
> > >
> > >        "How many PIC'engineers does it take to change a light bulb?"
> >
> > I get 74:
> >
> > 4 to argue that the light doesn't need to be changed
> > 17 to investigate alternative LED and CF technologies
> > 2 to complain about existing CF lamps
> > 4 to go buy diodes and resistors to put in series
> > 7 to make provocative political statements
> > 3 to write PIC assembler code to ramp the light up
> > 1 to write another version in C
> > 2 to design the hardware and actually change the lamp
> > 34 to try to reduce the assembler code by one instruction as a
'challenge'
> >
> > Oh, and additional 3 P.E.s to argue that many of the other people are
> > not really engineers at all and one more to complain that the count is
> off.
>
> Don't forget the 6 who try to unsubscribble.
>
> Ask Dmitry, he'll say 12.
>
And because it's that time of the year an individual who calls himself X
with an Email Address of 8-)@NotAnISP.net who demands a full and detailed
write-up of the whole project.

Chris Carr

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2001\07\04@172902 by Brian Kraut

picon face
I used to own a disco and stage lighting company and I worked on a lot of
halogen fixtures using several hundred watt bulbs.  Oxidized sockets were a
leading cause of getting low bulb life.  Try cleaning your sockets with some
Scotchbright or fine sandpaper.  Might be a good idea to turn the light off
first.

I imagine that we will all be buying $10.00 LED white light bulbs in a few years
instead of the compact flourescents.  White LEDs have not been out all that long
and the price should drop a lot in the next five years.

michael brown wrote:

{Quote hidden}

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2001\07\04@204945 by Tom Handley

picon face
  Jinx, typical compact fluorescent bulbs have color temperatures of around
2700K to 3200K (Warm White) which is closer to tungsten bulbs which range
from 2100K to 3200K. Typical `bluish' Daylight fluorescent tubes are 6400K.
Another thing about compact fluorescents is the use of a solid-state ballast
which eliminates the annoying flicker in addition to the energy savings.

  - Tom

At 01:01 PM 7/4/01 +1200, Jinx wrote:
{Quote hidden}

------------------------------------------------------------------------
Tom Handley
New Age Communications
Since '75 before "New Age" and no one around here is waiting for UFOs ;-)

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2001\07\04@210633 by Olin Lathrop

face picon face
> > Personally, I use compact flourescents except
> > where the bulb is turned on and off frequently...
>
> Is this hard on the light?  I've been using them for
> 7 years - They don't seem to last as long as claimed.
> Phillips 15W compact fluorescents used in my desklamp
> last about half the published lifetime.

I believe that florescents don't like to be frequently turned on, but I
don't remember where I heard that or understand the reason.


********************************************************************
Olin Lathrop, embedded systems consultant in Littleton Massachusetts
(978) 742-9014, spamBeGoneolinspamKILLspamembedinc.com, http://www.embedinc.com

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2001\07\05@050240 by Roman Black

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face
We can get 6000mCd white leds for $2.95 US,
does someone know the conversion from lumens
to candela, and how many lumens a 60w bulb
normally puts out?
-Roman

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2001\07\05@050648 by Roman Black

flavicon
face
Spehro Pefhany wrote:
>
> At 08:28 AM 7/4/01 -0400, you wrote:
> >[LED buld replacements]
> >> why cant I just buy a light
> >> source built onto a pcboard that just screws into the socket.
> >
> >This is coming, but not quite yet.  The price would still be too high to
> >achieve the volumes necessary.  Note that LED lights are currently going
> >into applications where the cost of changing the bulb is very high, the
> >light gets switched on/off frequently, and the light is an indicator as
> >apposed to providing general illumination.
>
> Also, as indicators, most of them are monochromatic (traffic signals, brake
> lights on buses), where most of the energy from the incandescent is wasted
> in the filter.


And in traffic lights the 20 degree directionality
of the leds is desirable, very unlike house lighting.
:o)
-Roman

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2001\07\05@051723 by Roman Black

flavicon
face
John Gardner wrote:
>
> Olin Lathrop wrote:
> > ...
> > Personally, I use compact flourescents except
> > where the bulb is turned on and off frequently...
>
> Is this hard on the light?  I've been using them for
> 7 years - They don't seem to last as long as claimed.
> Phillips 15W compact fluorescents used in my desklamp
> last about half the published lifetime.


Jack, they REALLY hate the heat. Desk lamps tend
to get very hot from the metal bucket around the lamp.
Some ceiling fittings you cant use compact fluoros
as they blow every few weeks. Try it in a HOT country
with the added burden of 240vac mains! :o)
-Roman

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2001\07\05@055329 by Jinx

face picon face
> 2700K to 3200K (Warm White) which is closer to tungsten bulbs
>    - Tom

Thanks for the info. Think I'll grab one to try in an anglepoise desk
lamp which is a little tricky/dangerous to install a resistor into

And thanks also to Morgan for his information

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2001\07\05@141423 by gaston.gagnon

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John Gardner wrote:
>
> Olin Lathrop wrote:
> > ...
> > Personally, I use compact flourescents except
> > where the bulb is turned on and off frequently...
>
> Is this hard on the light?  I've been using them for
> 7 years - They don't seem to last as long as claimed.
> Phillips 15W compact fluorescents used in my desklamp
> last about half the published lifetime.
>

My desk lamp has a three position switch for OFF - HALF - FULL. I did not open the switch but I
guess the half intensity is done with a diode. If my guess is right on the diode, IIRC these lamps
will not last very long if supplied with half cycle power.

> regards, Jack
>
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2001\07\05@195122 by Anders_Mejl=E6nder_Jakhelln?=

flavicon
face
To all you bulb guys, check out this:

http://users.iafrica.com/a/ar/artech/

Any ideas on how it works?

And look at the size of it http://users.iafrica.com/a/ar/artech/specs.htm

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2001\07\05@232521 by Dan Larson

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face
On Wed, 4 Jul 2001 18:39:03 -0400, Brian Kraut wrote:

>I used to own a disco and stage lighting company and I worked on a lot of
>halogen fixtures using several hundred watt bulbs.  Oxidized sockets were a
>leading cause of getting low bulb life.  Try cleaning your sockets with some
>Scotchbright or fine sandpaper.  Might be a good idea to turn the light off
>first.

Naw, don't turn the light off! ... And use steel wool too! He He He <VBEG>

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2001\07\06@045336 by Peter L. Peres

picon face
I once built a nightlight prototype using 10 medium efficiency 5mm green
LEDs (I should have used red). It was way, way, way too bright in a
largish dark bedroom.

Peter

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2001\07\06@050202 by Roman Black

flavicon
face
Anders Mejlænder Jakhelln wrote:
>
> To all you bulb guys, check out this:
>
> http://users.iafrica.com/a/ar/artech/
>
> Any ideas on how it works?
>
> And look at the size of it http://users.iafrica.com/a/ar/artech/specs.htm


Looks very nice! It's obviously a small potting
container, probably using one of the new SMT
triacs (Farnell have some juicy new SMT power
semis in their new catalogue) and by my guess
also has a little PIC or other embedded controller
with an Xc supply.

All considered, a very impressive product. But is
it designed to last the distance or just for a
few months??
:o)
-Roman (who hates fixing things)

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2001\07\06@132421 by Harold M Hallikainen

picon face
On Wed, 4 Jul 2001 11:01:12 -0400 Spehro Pefhany <@spam@speffRemoveMEspamEraseMEINTERLOG.COM>
writes:
> Also, as indicators, most of them are monochromatic (traffic
> signals, brake
> lights on buses), where most of the energy from the incandescent is
> wasted
> in the filter.


       Another clever thing on some LED traffic lights...  Those lights that
have an arrow (like a green arrow for a left turn) have the LEDs arranged
to make the arrow. An incandescent, of course, is behind a mask in the
shape of the arrow so only a fraction of the light gets out. The LEDs
just don't generate the light where it is not needed.

Harold

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2001\07\06@132428 by Harold M Hallikainen

picon face
On Wed, 4 Jul 2001 00:00:50 -0400 Brandon Fosdick <EraseMEbfozspam@spam@GLUE.UMD.EDU>
writes:
>
> The Feb 2001 issue of Scientific American has an article that
> answers your
> question. Unfortunately its not accessible from their web site. The
> short answer
> is that its a cost/consumer acceptance problem. Its not yet cheap
> enough to
> compete with conventional lighting in the home market, but its
> making headway in
> commercial and utility applications, namely traffic lights. The
> article also
> says that only 10% of the traffic lights in the US are LED based.
>


       In the past couple months, pretty much all the traffic lights here have
been changed to LED. I kinda wonder what the electronics to run an LED on
120VAC looks like. I'd expect some sort of boost switcher acting as a
constant current source into a bunch of LEDs in series. Not really very
simple or cheap.  In an effort to save electricity, you certainly don't
want to just use a big current limit resistor!

Harold

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2001\07\06@133244 by rottosen

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face
Harold M Hallikainen wrote:
{Quote hidden}

The traffic light my friend Al Brown reverse engineered used a capacitor
to limit the current.

Roman Black was kind enough to put Al's schematic on his web page at:
http://centauri.ezy.net.au/~fastvid/tube4w.htm


-- Rich



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2001\07\06@134320 by Marc Reinig

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face
Part of the thrust in going to LED's (in addition to the lifetime savings on
electric cost compared to the increased bulb cost) is the increased life and
hence the reduction in the cost actually replacing the bulbs over a period
of years, ignoring the cost of the bulbs.  I.e., the cost of a municipal
truck, with a high loader and a crew of at least two each time a light bulb
needs changing.

Marc Reinig
System Solutions

{Original Message removed}

2001\07\06@181504 by Barry Gershenfeld

picon face
At 07:02 PM 7/5/01 +1000, you wrote:
>We can get 6000mCd white leds for $2.95 US,
>does someone know the conversion from lumens
>to candela, and how many lumens a 60w bulb
>normally puts out?
>-Roman

I have a box of 75W bulbs here; it says 1170 lumens.
When I remember I'll check the 60W box.

Wait--this is the Internet...lessee...I can put in
1170 lumens, and...yep, here it is... 60W= 820 lumens.

(Buoyed by that success, I go back and search on lumens/
candela...presto! )

..."multiply Candela by 12.57 (4pi) to get Lumen"...

Assuming the LED is spherical (which it ain't...)

Barry

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2001\07\06@220641 by Patrik Husfloen

picon face
> ..."multiply Candela by 12.57 (4pi) to get Lumen"...

If I'm not mistaken Lumens isn't messuring the same thing as Candela
where one is emitted light, and the other, "strength" (I can't remeber the correct word) at a certain point.

I might be wrong about that but it's something like that.

Patrik

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2001\07\07@010741 by Roman Black

flavicon
face
Barry Gershenfeld wrote:
{Quote hidden}

Hmm, so 1 Cd = 12.57 lumens, so 1 mCd = 0.01257 lumens
so a 6000mCd white LED is about 75 lumens.

So, 60w bulb = 820 lumens = 11 LEDs!

Wow, this is almost viable now, since we can get the
white LEDs for under $2 US each.

Now we just have the problem you so rightly mentioned
re the spherical light output from a bulb, and the
rather poor LED dispersion of 15% or 20% from a beam.

Still very tempting for some lighting purposes.
Using Richard's "traffic light" Xc circuit, it should
be easy to build a very efficient LED "bulb"...
-Roman

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2001\07\07@035615 by Jinx

face picon face
> At 07:02 PM 7/5/01 +1000, you wrote:
> >We can get 6000mCd white leds for $2.95 US,
> >does someone know the conversion from lumens
> >to candela, and how many lumens a 60w bulb
> >normally puts out?
> >-Roman

I picked up an 18W fluorescent just to try it out (very nice btw, and
my work bench doesn't get all hot like it did with the 100W filament
bulb)

On the packet are some figures for watts to lumens. Also there are
some pictograms for "don't do's" that I can't figure out. I'd appreciate
any suggestions. The first I assume is don't use a dimmer, the
second might be don't use a timer (eh ?). I've put scan of them
here

http://home.clear.net.nz/pages/joecolquitt/fluoro.html

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2001\07\07@040701 by Jinx

face picon face
> Now we just have the problem you so rightly mentioned
> re the spherical light output from a bulb, and the
> rather poor LED dispersion of 15% or 20% from a beam.

As I mentioned a couple of weeks ago, I replaced the bulb in
a bicycle headlight with a white LED. Looking around the
displays in bike shops, I notice that all of the LED lights on
sale (usually 4 ultrabright greens or yellows) have the LED
pointing forward, making use of the LEDs lens. Bright, but
directional. However, my one white LED pointing backwards
into a parabolic reflector is just as noticeable and at up to
45 degrees either side too. Possibly there may be an app
there for an LED spotlight (kitchen, track lighting, mood
lighting etc). I have to get a some white LEDs this week
for another job, I'll see if I can make a useable house bulb

http://home.clear.net.nz/pages/joecolquitt/bikelamp.html

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2001\07\07@041251 by Graeme Zimmer

flavicon
face
Hi,

> On the packet are some figures for watts to lumens. Also there are
> some pictograms for "don't do's" that I can't figure out. I'd appreciate
> any suggestions. The first I assume is don't use a dimmer, the
> second might be don't use a timer (eh ?). I've put scan of them
> here

Don't use a dimmer, a timer, a sun sensor, or a dark sensor.

Why ever not? I guess they are talking about using cheap and nasty triac
controlled sensors.

I can understand a dimmer causing problems, but if a timer or sun sensor
used a relay I recon it would be OK.....


.................. Zim

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2001\07\07@043159 by Jinx

face picon face
> Don't use a dimmer, a timer, a sun sensor, or a dark sensor.
>
> Why ever not? I guess they are talking about using cheap and
> nasty triac controlled sensors.
>
> I can understand a dimmer causing problems, but if a timer or
> sun sensor used a relay I recon it would be OK.....
>
> .................. Zim

I couldn't understand the caveats either, you don't find them
on filament bulb packets. And particularly as GE don't say
WHY not to use alternatives to an ordinary switch. Being a
bit presumptuous of them IMO. Here they mention only
dimmers

http://www.gelighting.com/apo/home/home_compact_fluorescent.html#

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2001\07\07@071600 by Peter L. Peres

picon face
> LED traffic lights

Of course everyone realises that in the event of a major surge or EMP all
the traffic lights will die. With or without switchers. (LEDs don't like
reverse biasing).

Peter

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2001\07\07@090551 by Olin Lathrop

face picon face
> Wait--this is the Internet...lessee...I can put in
> 1170 lumens, and...yep, here it is... 60W= 820 lumens.

That's also the problem with the internet - interpretation of the results is
solely your responsibility.  60 watts definitely does not equal 820 lumens.
This is a typical number of lumens produced by a 60W incandescent bulb.  I
was in the store yesterday and looked at LEBs (Light Emitting Bulbs <g>).  I
saw the "normal" 60W Sylvania bulbs rated as 870 lumens, and the "double
life" 60W Sylvania bulbs at 800 lumens.

It would be interesting to find the real lumens per watt.  Then we could
figure out how hideously ineffecient incandescent bulbs really are.


********************************************************************
Olin Lathrop, embedded systems consultant in Littleton Massachusetts
(978) 742-9014, spamBeGoneolinEraseMEspamembedinc.com, http://www.embedinc.com

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2001\07\07@093248 by mike

flavicon
face
On Sat, 7 Jul 2001 20:31:13 +1200, you wrote:

>> Don't use a dimmer, a timer, a sun sensor, or a dark sensor.
>>
>> Why ever not? I guess they are talking about using cheap and
>> nasty triac controlled sensors.
>>
>> I can understand a dimmer causing problems, but if a timer or
>> sun sensor used a relay I recon it would be OK.....
>>
>> .................. Zim
>
>I couldn't understand the caveats either, you don't find them
>on filament bulb packets. And particularly as GE don't say
>WHY not to use alternatives to an ordinary switch. Being a
>bit presumptuous of them IMO. Here they mention only
>dimmers
>
>http://www.gelighting.com/apo/home/home_compact_fluorescent.html#

Electronic timers etc. typically rely on a small current through the
bulb (in 'off' mode) for power. An electronic ballast would probably
either not pass enough current, or the phase shift caused by the
capacitor would cause problems, or the small current through the timer
in 'off' mode might cause occasional flickering as the cap slowly
charges and the lamp tries to start.  
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2001\07\07@113219 by Patrik Husfloen

picon face
Neat, I was looking to do the same thing, though I have a dynamo/generator driving my bulbs.
so I guess I'd need some rectifier circuit, using a backup cap to give som glow while stopped might be nice also.
too bad I have no clue on electronics :)


{Original Message removed}

2001\07\07@185643 by Jinx

face picon face
> From: Patrik Husfloen

> Neat, I was looking to do the same thing, though I have a dynamo/
> generator driving my bulbs.so I guess I'd need some rectifier circuit,
> using a backup cap to give som glow while stopped might be nice
> also. too bad I have no clue on electronics :)

The huge advantage of using white LEDs over filament bulbs is that
they use a fraction of the power. A white LED takes around 8-15mA
(depending on what resistor you put in series) at very good brightness,
whereas a filament bulb may be 50 times that. I run all my lights off a
6V 3Ah gel cell under the saddle, which needs a quick topping up
once a fortnight. Where possible I run the wiring through the frame.
Even if I forget to turn the lights off it won't do much harm for a few
hours. Here's what I've been up to for a few days, to which I've just
added pics of the lighting for you to help explain. It's a work in
progress so some pics aren't quite consistent

http://home.clear.net.nz/pages/joecolquitt/0trailer.html

The lights that came with the bike have 5 green (front) and 3 red (back).
and each use 110mA running on 2 x AA alkalines. I try not to use them
except in traffic. The lights I've added are one white (8mA) on the handle
bars, the same planned for the front of the trailer (as soon as I pick up
some more white LEDs) using a piece of faceted plastic, and whites
inside recycled motorcycle rear light housings for the back of the bike
and the trailer. So 4 very bright lights for less than 40mA. Additionally
I'll be trying a sensor on the brake cable for flashing the rears (with the
aid of a PIC), and possibly PIC-controlled indicators, particularly on the
back of the trailer. And I expect come Christmas there'll be party lights
and a Ho-Ho waving Santa too ;-)

I'm already looking around for a nodding chihuahua to stick on the
back. Which may seem trivial, but anything that makes me more
noticeable (and gives car drivers a laugh at my expense) is a safety +

Two other points -

Cars give me a very wide berth around the trailer and I feel safer with
it than without it (except with a 12000psi oxygen bottle on board he he)
I am so glad I've made it. The stuff I've been hauling around just couldn't
be done on a plain bike. God help me when I've got time to visit the
industrial estates and rummage through their dumpsters. Already
counting the days until the next inorganic collection ;-)

And this point for careless drivers - for 50c and your number plate I
can find out where you live !!!! Maybe I'll pay your car a visit one dark
night if you piss me off

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2001\07\07@203413 by Jinx

face picon face
part 1 696 bytes content-type:text/plain; (decoded 7bit)

> Neat, I was looking to do the same thing, though I have a
> dynamo/generator driving my bulbs. so I guess I'd need
> some rectifier circuit, using a backup cap to give som glow
> while stopped might be nice also. too bad I have no clue on
> electronics :)

NiCads would do, trickle charge them off the dynamo. Summat
like this basic circuit would be OK. The resistor R may need to
be something more sophisticated (constant voltage or constant
current block) depending on the dynamo and battery type. A
super cap would also work instead of a battery. I think common
ones give you around 1mA for 30 minutes, perhaps then 20mA
for a minute ?






part 2 1771 bytes content-type:image/gif; (decode)


part 3 144 bytes
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2001\07\07@214340 by Alexandre Domingos F. Souza

flavicon
face
>short life span.  Is it possible that there is not a more efficient way?
>Traffic lights are all becoming LED based, why cant I just buy a light
>source built onto a pcboard that just screws into the socket.  With the
>variety of LED colors available now, simulating a basically white light with
>LED's shouldn't be that hard.  I realize the "quality of whiteness" might
>not be ideal, but in your basement, shed, garage, or attic, who cares?

       In photography, you can use special "led lights" that are screwed (? right word ?) in the 110V socket. And they are fancy!


---8<---Corte aqui---8<----

Alexandre Souza
taitospamBeGonespamterra.com.br
http://planeta.terra.com.br/lazer/pinball/

---8<---Corte aqui---8<----

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2001\07\07@214753 by Alexandre Domingos F. Souza

flavicon
face
>After all this talk to date on extending bulb life, etc., one simply has to
>ask:
>        "How many PIC'engineers does it take to change a light bulb?"

       It depends of the pic being used


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Alexandre Souza
RemoveMEtaito@spam@spamspamBeGoneterra.com.br
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2001\07\08@002754 by Michael C. Reid

flavicon
face
-----Original Message-----
From: Michael C. Reid [.....mikecreid@spam@spamEraseMEqwest.net]
Sent: Friday, July 06, 2001 4:29 PM
To: .....rottosenRemoveMEspamidcomm.com
Subject: RE: [EE]: Bulb Life


At Light fair international, held in Las Vegas in May, our booth (Centralite
Systems, we make low voltage lighting control systems for luxury homes) was
next to an LED fixture company.  In their small incandescent replacement
LED's, they use the reactance of a capacitor in series with the 120 vac
input to drop the AC down to a level where they can power the LED's.  They
also I believe had some type of voltage regulator in the circuit.  They said
the problem is with heat dissipation from some types of LED's, such as the
blue LED's, as they consume more current.  The crowds were sure attracted to
the fixtures they were displaying.

-----Original Message-----
From: pic microcontroller discussion list
[.....PICLISTSTOPspamspam@spam@MITVMA.MIT.EDU]On Behalf Of Richard Ottosen
Sent: Friday, July 06, 2001 11:30 AM
To: PICLISTEraseMEspam@spam@MITVMA.MIT.EDU
Subject: Re: [EE]: Bulb Life


Harold M Hallikainen wrote:
{Quote hidden}

have
> been changed to LED. I kinda wonder what the electronics to run an LED on
> 120VAC looks like. I'd expect some sort of boost switcher acting as a
> constant current source into a bunch of LEDs in series. Not really very
> simple or cheap.  In an effort to save electricity, you certainly don't
> want to just use a big current limit resistor!
>
> Harold
>


The traffic light my friend Al Brown reverse engineered used a capacitor
to limit the current.

Roman Black was kind enough to put Al's schematic on his web page at:
http://centauri.ezy.net.au/~fastvid/tube4w.htm


-- Rich



> ________________________________________________________________
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2001\07\08@003229 by Roman Black

flavicon
face
Peter L. Peres wrote:
>
> > LED traffic lights
>
> Of course everyone realises that in the event of a major surge or EMP all
> the traffic lights will die. With or without switchers. (LEDs don't like
> reverse biasing).


Interesting! Would you suggest a reverse diode
across the LED array? Or better still a big zener
or specialty surge diode, this would protect for
both forward and backward surges, considering
there should be a fair series resistance anyway?
-Roman

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2001\07\08@050743 by Chris Carr

flavicon
face
For those of you wanting to drive a White LED of a single NiCad NiMH cell
you may care to look at this Application Note

http://www.zetex.com/3.0/appnotes/apps/an33.pdf

8Watt Fluorescent Lamp Inverter

http://www.zetex.com/3.0/appnotes/apps/an1.pdf

and although it's a bit off topic for those of you interested in Infra Red
Communications

http://www.zetex.com/3.0/appnotes/apps/an3.pdf

Regards

Chris Carr

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2001\07\08@062600 by Jinx

face picon face
> I once built a nightlight prototype using 10 medium efficiency
> 5mm green LEDs (I should have used red). It was way, way,
> way too bright in a largish dark bedroom.
>
> Peter

If the purpose of the light was illumination rather than a comforter
then green would be a good choice, as that's the colour the eye
has most sensitivity to

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2001\07\08@062608 by Jinx

face picon face
> Electronic timers etc. typically rely on a small current through the
> bulb (in 'off' mode) for power. An electronic ballast would probably
> either not pass enough current, or the phase shift caused by the
> capacitor would cause problems, or the small current through the
> timer in 'off' mode might cause occasional flickering as the cap
> slowly charges and the lamp tries to start.

So GE are just issuing a very generalised warning about
electronic control of fluorescents. Switching with a relay would
be OK, what is there in that type of fluorescent that could cause
trouble with a simple triac switch (ie bulb as load between triac
and N) ?

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2001\07\08@104613 by Roman Black

flavicon
face
Jinx wrote:
>
> > Electronic timers etc. typically rely on a small current through the
> > bulb (in 'off' mode) for power. An electronic ballast would probably
> > either not pass enough current, or the phase shift caused by the
> > capacitor would cause problems, or the small current through the
> > timer in 'off' mode might cause occasional flickering as the cap
> > slowly charges and the lamp tries to start.
>
> So GE are just issuing a very generalised warning about
> electronic control of fluorescents. Switching with a relay would
> be OK, what is there in that type of fluorescent that could cause
> trouble with a simple triac switch (ie bulb as load between triac
> and N) ?

The couple I have pulled apart seem to be a simple
rectifier to a filter cap, then use a high freq
inverter to drive the tube.
They should work fine off a relay, triac or even
a series diode, but dimming using a triac and
phase angle switching would not be nice.
-Roman

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2001\07\08@183330 by Jinx

face picon face
> The couple I have pulled apart seem to be a simple
> rectifier to a filter cap, then use a high freq
> inverter to drive the tube.
> They should work fine off a relay, triac or even
> a series diode, but dimming using a triac and
> phase angle switching would not be nice.
> -Roman

I wondered about the dimmer "don't do" on the packet. You'll
notice it's in a triangle and a different shading to give it special
prominence. Pity though with all the empty space around those
warnings they didn't take a minute to elucidate

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2001\07\08@204141 by Drew Ames

flavicon
face
How about "Don't run from a power source derived from stored Soar Energy".





Jinx <spamBeGonejoecolquittKILLspamspam@spam@CLEAR.NET.NZ> on 07/07/2001 05:25:06 pm

Please respond to pic microcontroller discussion list <PICLISTspam_OUTspam@spam@MITVMA.MIT.EDU>

To:   spamBeGonePICLIST@spam@spamMITVMA.MIT.EDU
cc:    (bcc: Drew AMES/SGIOGRP)
Subject:  Re: [EE]: Bulb Life



On the packet are some figures for watts to lumens. Also there are
some pictograms for "don't do's" that I can't figure out. I'd appreciate
any suggestions. The first I assume is don't use a dimmer, the
second might be don't use a timer (eh ?). I've put scan of them
here

http://home.clear.net.nz/pages/joecolquitt/fluoro.html

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2001\07\08@230839 by Roman Black

flavicon
face
Jinx wrote:
>
> > The couple I have pulled apart seem to be a simple
> > rectifier to a filter cap, then use a high freq
> > inverter to drive the tube.
> > They should work fine off a relay, triac or even
> > a series diode, but dimming using a triac and
> > phase angle switching would not be nice.
> > -Roman
>
> I wondered about the dimmer "don't do" on the packet. You'll
> notice it's in a triangle and a different shading to give it special
> prominence. Pity though with all the empty space around those
> warnings they didn't take a minute to elucidate


Ha ha! They don't want to educate you, they want
to keep you as stupid as possible and buying as many
bulbs as possible. Evil empires are like that! ;o)
-Roman

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2001\07\09@132704 by Mike Mansheim

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face
Hey Roman - I know this hasn't been mentioned for a while,
but I was wondering:  how do you physically implement
the 5% resistors?
Thanks.

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2001\07\10@180614 by Peter L. Peres

picon face
> Peter L. Peres wrote:
>>
>> > LED traffic lights
>>
>> Of course everyone realises that in the event of a major surge or EMP
>> all the traffic lights will die. With or without switchers. (LEDs
>> don't like reverse biasing).
>
>> Interesting! Would you suggest a reverse diode across the LED array?
> Or better still a big zener or specialty surge diode, this would
> protect for both forward and backward surges, considering there should
> be a fair series resistance anyway? -Roman

I have no idea. Many LEDs in parallel have a lot of capacitance but they
are usually wired in series-parallel groups in a lamp. Perhaps a polyfuse
in series would save them from something coming from the wire, along with
a reverse protection diode or a special diode.

Peter

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2001\07\10@184834 by Peter L. Peres

picon face
Afaik, having played a lot with mercury vapor discharge lamps, the warning
about not running them on a dimmer is serious. You see, most mercury
discharge lamps store the mercury in amalgamated anodes and mercury vapor
discharges with asymetrical steering (like a starting or stuttering
dimmer), are actually rectifiers. If you try to dim one of those it will
probably become unbalanced, start rectifying, and 'cook' the ballast or
dimmer. The nice part is that once unbalanced they stay so until they cool
down and are restarted. They also get to choose the polarity (randomly)
;-(. Unless otherwise specified, either run the anodes at operating
temperature (implies full power) or not at all.

Peter

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2001\07\10@234734 by Roman Black

flavicon
face
Mike Mansheim wrote:
>
> Hey Roman - I know this hasn't been mentioned for a while,
> but I was wondering:  how do you physically implement
> the 5% resistors?
> Thanks.


Hi Mike, the idea is to drop 5% of the mains
voltage across the series resistor and 95%
across the bulb. 8% is even better.

Assuming 120vac mains, 60w bulb, gives 0.5amp,
so you need about a 12 ohm resistor, which drops
about 6v. It will dissipate 3w, so use a 10w
resistor, which will still get hot.

You may need to fiddle with resistor values
to get a result you are happy with. :o)
-Roman

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2001\07\11@024926 by Jinx

face picon face
> Assuming 120vac mains, 60w bulb, gives 0.5amp,
> so you need about a 12 ohm resistor, which drops
> about 6v. It will dissipate 3w, so use a 10w
> resistor, which will still get hot.

A 47R 10W (240VAC/60W bulb) reaches 63degC

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2001\07\11@081836 by Scott M. Thomas

flavicon
face
How did you determine the temperature?  Do you have a formula?

-----Original Message-----
From: Jinx [EraseMEjoecolquittRemoveMEspamSTOPspamCLEAR.NET.NZ]
Sent: Wednesday, July 11, 2001 2:47 AM
To: RemoveMEPICLISTKILLspamspamTakeThisOuTMITVMA.MIT.EDU
Subject: Re: [EE]: Bulb Life


> Assuming 120vac mains, 60w bulb, gives 0.5amp,
> so you need about a 12 ohm resistor, which drops
> about 6v. It will dissipate 3w, so use a 10w
> resistor, which will still get hot.

A 47R 10W (240VAC/60W bulb) reaches 63degC

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2001\07\11@082051 by Scott M. Thomas

flavicon
face
Sorry if I missed this, but how much will this increase the life of the
bulb?

-----Original Message-----
From: Roman Black [spamBeGonefastvidspam@spam@EZY.NET.AU]
Sent: Tuesday, July 10, 2001 11:48 PM
To: RemoveMEPICLISTspam_OUTspamMITVMA.MIT.EDU
Subject: Re: [EE]: Bulb Life


Mike Mansheim wrote:
>
> Hey Roman - I know this hasn't been mentioned for a while,
> but I was wondering:  how do you physically implement
> the 5% resistors?
> Thanks.


Hi Mike, the idea is to drop 5% of the mains
voltage across the series resistor and 95%
across the bulb. 8% is even better.

Assuming 120vac mains, 60w bulb, gives 0.5amp,
so you need about a 12 ohm resistor, which drops
about 6v. It will dissipate 3w, so use a 10w
resistor, which will still get hot.

You may need to fiddle with resistor values
to get a result you are happy with. :o)
-Roman

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2001\07\11@092256 by Roman Black

flavicon
face
Scott M. Thomas wrote:
>
> How did you determine the temperature?  Do you have a formula?

Ha ha!!! I guess he's got a thermometer! ;o)
-Roman



> {Original Message removed}

2001\07\11@093541 by Roman Black

flavicon
face
Scott M. Thomas wrote:
>
> Sorry if I missed this, but how much will this increase the life of the
> bulb?
>
> {Original Message removed}

2001\07\11@094748 by Roman Black

flavicon
face
chucksea@mindspring.com wrote:
>
> I think what he was asking was the nuts
> and bolts of how do you do the actual wiring?
> Does the resistor go in the socket somehow?
> Do you have to pull the fixture out of the
> ceiling and add a resistor inline with wirenuts,
> black tape, etc??


> > Hey Roman - I know this hasn't been mentioned for a while,
> > but I was wondering:  how do you physically implement
> > the 5% resistors?
> > Thanks.

OK, point taken. I can't really help you here.
The resistor will dissipate maybe 3w with a 60w
bulb. That is a HOT resistor. You need at least
a 10w resistor.
As Jinx said, expect maybe 40'C temp rise
(60+ degrees at the resistor) so that is very "ouch".

My experience was as an apprentice where the
oldtimers showed me some high outdoor light fittings
that had 5% drop resistors, so they didn't have
to change bulbs. The bulbs last for many years.

I have used this with excellent result in a 100w
incubator, using 7% volts drop on the resistors, and
I used 2 large 20w ceramic resistors because I have
heaps of that stuff in my junkbox. :o)
The incubator has done thousands of on/off cycles over
months, still the original 100w bulb.
-Roman

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2001\07\11@103535 by Spehro Pefhany

picon face
At 11:36 PM 7/11/01 +1000, you wrote:

>I would also like to see the white LED lighting topic
>explored further, high initial costs don't bother me
>if it gives power savings over 20 years. I'm using
>stuff now that I built 20 years ago.

Roman, you might want to look at:

http://www.philips.com/themes/led/

They are thinking it might be practical for general lighting in ~5 years,
not bad IMHO. As they say, the best of the white LEDs are now more
efficient than ordinary incandescents, so it boils down to further
improvments in efficiency (hopefully to surpass flourescents) and reducing
the cost.

Best regards,

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spam_OUTspeffspam_OUTspamspam_OUTinterlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
Contributions invited->The AVR-gcc FAQ is at: http://www.bluecollarlinux.com
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=

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2001\07\11@105232 by Roman Black

flavicon
face
Spehro Pefhany wrote:
>
> >I would also like to see the white LED lighting topic
> >explored further, high initial costs don't bother me

> http://www.philips.com/themes/led/
> They are thinking it might be practical for general lighting in ~5 years,
> not bad IMHO. As they say, the best of the white LEDs are now more
> efficient than ordinary incandescents, so it boils down to further
> improvments in efficiency (hopefully to surpass flourescents) and reducing
> the cost.


Hi Spehro, if you haven't done so yet have a
play with a 6000mCd white led. I have one running
at only half power (25mA) that is a very effective
flashlight.

I can't believe Philips' claims of "not efficient yet"
i'm sure a hundred of these leds running from 240vac
would still only draw 50mA and give as much (or more)
light as a 60w bulb drawing 250mA.

I really don't see an efficiency issue, just an initial
cost issue.

And they make awesome "point lights" for looking down
in PCB crevices etc. Mine give more light at 2 inches
than a 40w 4 foot fluoro tube at 2". One of these days
I will take a picture of our point lights and put it
up on the net; 5x 110mAh NiCd, a stick, a switch,
a resistor and a white led.
One of the most useful tools I have ever built.
-Roman

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2001\07\11@111936 by Spehro Pefhany

picon face
At 12:52 AM 7/12/01 +1000, you wrote:
>
>Hi Spehro, if you haven't done so yet have a
>play with a 6000mCd white led. I have one running
>at only half power (25mA) that is a very effective
>flashlight.

The best ones I see at Digikey are ~2300mcd "typical"
at 20mA. For about $3 US each. So, if they are linear
they'd be around 6000mcd at 50mA. I designed a white-
LED microscope ring illuminator for a friend, but
I'll have to wait till I get out to California again
to actually see it in action. ;-)

>I can't believe Philips' claims of "not efficient yet"
>i'm sure a hundred of these leds running from 240vac
>would still only draw 50mA and give as much (or more)
>light as a 60w bulb drawing 250mA.

I think your order of magnitude is right. But an 11W
flourescent is about as bright too and is very cheap.

>I really don't see an efficiency issue, just an initial
>cost issue.

Efficiency would get it into leading edge applications
such as laptop backlights where cost isn't as big a
factor. Small size, low voltage and low power at
reasonable efficiency is getting them into many
specialized apps now.
But high cost will kill consumer applications
for sure. $15 retail is too much for many people, and if
there is no operating cost savings relative to CF, then
what is the unique selling proposition?

>And they make awesome "point lights" for looking down
>in PCB crevices etc. Mine give more light at 2 inches
>than a 40w 4 foot fluoro tube at 2". One of these days
>I will take a picture of our point lights and put it
>up on the net; 5x 110mAh NiCd, a stick, a switch,
>a resistor and a white led.
>One of the most useful tools I have ever built.

I'd like to see that. Sounds like a good idea. Maybe I'll
use one or two (depending if I feel like making a SMPS)
of those NiMH battery packs I picked up in Tucson and
make one.

I'd really like to have one of those lights that the
dentists use, though.

Best regards,
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2001\07\11@112532 by Byron A Jeff

face picon face
On Wed, Jul 11, 2001 at 11:47:50PM +1000, Roman Black wrote:
{Quote hidden}

Roman, let's start here. How did you wire the incubator? Where did you wire
the resistors relative to the light socket?

There are two major problems in wiring the resistor, high voltage and heat.
Of course this is the same two problems as wiring a light fixture, but with the
light fixture the source of heat is out in free space.

Ideally the resistor should be an a grounded, thermally coupled metal box
that's mounted in free space. It may be possible to get away with a deep
metal box at the light socket. Mount the resistor at the back of the box on
the side away from the stud. The box would then act as a heat sink for the
resistor. Note that IANAElectrician!

Frankly the thought of a radiated heat source mounted in wall is quite a scary
one.

BAJ

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2001\07\11@120210 by Roman Black

flavicon
face
Byron A Jeff wrote:

{Quote hidden}

I think you are geting the wrong end of the stick,
the 3w from the resistor is very little compared with
maybe 30w to 40w heat radiated from a 60w light bulb!!

Remember the resistor might get to 60'C, the bulb
gets to 85'C or more. Heating inside light fittings
is all relative. :o)

In the incubator I just mounted the resistors near
the bulb, it all heats the air for convection inside
the incubator cabinet anyway.

I agree not to mount a heat source inside the wall!!
Maybe in a metal light fitting, its a design decision
you have to make based on the application. It is ideal
for outdoor light fittings which are usually in a large
alloy metal waterproof box. There is no extra heat,
in total, as the mains voltage is fixed.
-Roman

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2001\07\11@120632 by Roman Black

flavicon
face
Spehro Pefhany wrote:
>
> At 12:52 AM 7/12/01 +1000, you wrote:
> >
> >Hi Spehro, if you haven't done so yet have a
> >play with a 6000mCd white led.
>
> The best ones I see at Digikey are ~2300mcd "typical"
> at 20mA. For about $3 US each. So, if they are linear
> they'd be around 6000mcd at 50mA.

I got mine from http://www.jaycarelectronics.com (I think)
they are listed as 6000mCd. 2300mCd sounds like the
older weaker leds.


> I designed a white-
> LED microscope ring illuminator for a friend, but
> I'll have to wait till I get out to California again
> to actually see it in action. ;-)

Cool! Literally too. :o)


> >I can't believe Philips' claims of "not efficient yet"
> >i'm sure a hundred of these leds running from 240vac
> >would still only draw 50mA and give as much (or more)
> >light as a 60w bulb drawing 250mA.
>
> I think your order of magnitude is right. But an 11W
> flourescent is about as bright too and is very cheap.

Good point. But you have to agree that solid state
lighting has a real appeal to it...


{Quote hidden}

Ok, i'll take a picture and put it up.
Coupl'a days... :o)
-Roman

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2001\07\11@145018 by uter van ooijen & floortje hanneman

picon face
> One more to recode it for the AVR, in half the space :)

And yet another to complain that AVRs measure code space in bytes and PICs
in instructions, so this is unfair. Yet another one will try to compare the
cost of AVR versus PIC on an equal footing, for instance the amount of Lumen
(Candela?) produced when connected directly to the mains (with or without
zero-crossing life extender).

Wouter

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2001\07\11@160808 by Alan Shinn

picon face
>Date:    Mon, 9 Jul 2001 20:13:51 +0300
>From:    "Peter L. Peres" <plpspamBeGonespam.....ACTCOM.CO.IL>
>Subject: Re: [EE]: Bulb Life

> Peter L. Peres wrote:
>>
>> > LED traffic lights
>>
>> Of course everyone realises that in the event of a major surge or EMP
>> all the traffic lights will die. With or without switchers. (LEDs
>> don't like reverse biasing).
>
>> Interesting! Would you suggest a reverse diode across the LED array?
> Or better still a big zener or specialty surge diode, this would
> protect for both forward and backward surges, considering there should
> be a fair series resistance anyway? -Roman
--

If you put half of your LED bank in parallel but with reverse polarity
(anti-parallel?) to the other half you get full wave power use and no
reverse polarity problems. You could also feed a non-anti-parallel
system with a full wave bridge rectifier if you want to buy an extra
part. Now use a series cap for non-dissipative current limiting and you
might have a survivable system (with the bridge system the cap is on an
input leg).

Looking forward:
Alan Shinn


Experience the
beginnings of microscopy.
Make your own replica
of one of Antony van Leeuwenhoek's microscopes.
visit    http://www.mindspring.com/~alshinn/

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2001\07\11@173428 by Jinx

face picon face
> How did you determine the temperature?  Do you have
> a formula?
>
> > A 47R 10W (240VAC/60W bulb) reaches 63degC

A temperature sensor on the multimeter

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2001\07\11@173436 by Jinx

face picon face
> Sorry if I missed this, but how much will this increase the life
> of the bulb?

http://home.clear.net.nz/pages/joecolquitt/0bulblife.html

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2001\07\11@185818 by Chris Carr

flavicon
face
Alan Shinn Wrote

{Quote hidden}

At last.  I have been watching this and waiting for someone to come up with
the back-to-back solution. I will now throw in my groats worth.

1. Back each individual LED with another one. Do not parallel long chains of
LED's. Why Not ? Hint : Consider the failure of a single LED.

2. Do not use a capacitor for current limiting. Why not ? Using Capacitive
reactance is very attractive (and effective). However, what tends to be
ignored is that interference travels through a series capacitive dropper
like a hot knife travels through Butter. So with a capacitive current
limiter your spike protection has to be considerably more robust than that
for a resistive (or better still an inductive) current limiter....Discuss

3. The Groat is a redundant English Coin which even I do not remember as a
lad, but I do remember the Farthing. Ah, happy days when there was 144 Pence
to the Pound.

Regards

Chris Carr

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2001\07\11@201247 by hard Prosser

flavicon
face
Just a quick note on the use of capacitors as voltage droppers -
Yes, high frequency disturbances do get through the series cap and upset
things - that's why capacitive dividers are much better. They also have the
advantage of lowering the source impedance somewhat and the shunt capacitor
doesn't need particularly  high voltage ratings.
You still need some form of spike supression however

Fair comment re the parallel operation - but do leds fail open or short? -
A combination of series and parallel leds would seem safest & be the best
way of driving a number off a convienient voltage.
But - the leds in the centre of the mass will run hotter, have a lower
forward voltage & hog the current - so do you add power - wasting dropping
resistors as well, or just try and organise the strings so parallel leds
are at musch the same temperature?


(144 pence to the pound ? - it was 240 where I live(d)).

Richard P









Alan Shinn Wrote

{Quote hidden}

At last.  I have been watching this and waiting for someone to come up with
the back-to-back solution. I will now throw in my groats worth.

1. Back each individual LED with another one. Do not parallel long chains
of
LED's. Why Not ? Hint : Consider the failure of a single LED.

2. Do not use a capacitor for current limiting. Why not ? Using Capacitive
reactance is very attractive (and effective). However, what tends to be
ignored is that interference travels through a series capacitive dropper
like a hot knife travels through Butter. So with a capacitive current
limiter your spike protection has to be considerably more robust than that
for a resistive (or better still an inductive) current limiter....Discuss

3. The Groat is a redundant English Coin which even I do not remember as a
lad, but I do remember the Farthing. Ah, happy days when there was 144
Pence
to the Pound.

Regards

Chris Carr

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2001\07\12@090556 by Paul Hutchinson

flavicon
face
> Fair comment re the parallel operation - but do leds fail open or short? -

I've seen both types of failure although open circuit has been most common
by a huge amount.

Paul

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2001\07\12@104233 by Roman Black

flavicon
face
Paul Hutchinson wrote:
>
> > Fair comment re the parallel operation - but do leds fail open or short? -
>
> I've seen both types of failure although open circuit has been most common
> by a huge amount.


Agreed. In IR remotes, the LEDs almost always
go OC. These get some of the worst high current
abuse that you expect from a led. I can't remember
the last SC led I found...
-Roman

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2001\07\12@141420 by Peter L. Peres

picon face
Off the shelf LEDs fail open (the bonding wire for the anode acts as a
fuse). LEDs in led modules (factory assembled) may fail short especillay
if they are very small (because they use something other than a wire to
bond the anode), exactly like Zeners in DOxxx (glass) case and any other
semiconductor not bonded with thin wires . Do not rely on this whatever
you do, check yours.

Peter

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2001\07\12@152110 by Peter L. Peres

picon face
> Frankly the thought of a radiated heat source mounted in wall is quite a
> scary one.

Imho you are forgetting that in most backward (g) nations walls are still
made of bricks, mortar, and concrete, and it's ok to put radiated heat
sources in them most of the time. Sometimes this is done deliberately
(floor heating).

Peter

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2001\07\12@155025 by David VanHorn

flavicon
face
At 07:54 PM 7/12/01 +0300, Peter L. Peres wrote:
> > Frankly the thought of a radiated heat source mounted in wall is quite a
> > scary one.
>
>Imho you are forgetting that in most backward (g) nations walls are still
>made of bricks, mortar, and concrete, and it's ok to put radiated heat
>sources in them most of the time. Sometimes this is done deliberately
>(floor heating).

Like Indiana??   Here, brick and reinforced concrete are a good idea, due
to the occasional tornado.

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2001\07\15@232847 by Jinx

face picon face
> Ha ha! They don't want to educate you, they want
> to keep you as stupid as possible and buying as many
> bulbs as possible. Evil empires are like that! ;o)
> -Roman

Appropriate then that this is posted under an [EE] Evil Empires
tag. What truth is there really to planned obsolescence ? Any
proven examples ? Light bulbs and tyres spring to mind as
products widely believed to be "improvable"

btw, as I travel around I pop into the odd electrical wholesaler
and always leave a copy of my bulb life web page and some
comments from the list (anonymous of course) about extending
filament bulb life. Had a few "ooohs" from counter staff as they
realised the implications

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'[EE]: Bulb Life'
2001\11\16@234148 by Jinx
face picon face
Anyone else see this on TV this week ? On the show I saw
it on (World News Tonight with Peter Jennings) they had a
view from below the bulb. The filament, quite by accident,
spells "ON"

http://www.janeellen.com/musings/livermor.html

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2001\11\17@013024 by Kathy Quinlan

flavicon
face
whooooaaahhhhhh

I like that one, I wish mine would last more than a few weeks :o(

Maybe I should start a thread about bublife and why new bulbs fail so much
:o(

The toilet light bulb ( a yellow anti insect one 40W) lasted for 4 years,
the replacements are averaging 6 months, it is not turned on and off all the
time, it gets turned on as it gets dark, and left on till it is light in the
morning (have young kids lol)

all my 100W bulbs around the place blow regularly sigh, I guess they are
made to fail so we keep buying them

Regards,

Kat.

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{Original Message removed}

2001\11\17@021443 by Russell McMahon

picon face
> The toilet light bulb ( a yellow anti insect one 40W) lasted for 4 years,
> the replacements are averaging 6 months, it is not turned on and off all
the
> time, it gets turned on as it gets dark, and left on till it is light in
the
> morning (have young kids lol)
>
> all my 100W bulbs around the place blow regularly sigh, I guess they are
> made to fail so we keep buying them


Kathy,

you are a prime candidate for a "fluorescent" bulb.
These now sell regularly for $NZ10 here so should be similar there.
A replacement fluro' bulb will require about 6 watts.

As a rule of thumb, if electricity is $0.10 a unit then it will cost you $1
per year per watt for a bulb turned on 24 hrs a day.
So a 40 watt bulb turned on say 10 hrs/day costs, relative top a 6 watt bulb
= ($40 - $6) x 10/24 =~ $14 per year for power. Add about $1.50 for 2 bulbs
per year and your payback time for the fluro is about 8 or 9 months. The
fluro should last several years (keep the packet and clip the receipt to it
for the ones that don't :-) ).



       Russell McMahon

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2001\11\17@043715 by Jinx

face picon face
> whooooaaahhhhhh
>
> I like that one, I wish mine would last more than a few weeks :o(
>
> Maybe I should start a thread about bublife and why new bulbs
> fail so much :o(

Sounds like you weren't around for the great debate at the beginning
of the year. Hoo boy, did bulbs get a work-out ! As a result, where
possible I've changed to fluorescents and to the filament bulbs added
series resistors

http://home.clear.net.nz/pages/joecolquitt/bulblife.html

The five months mentioned is now ten

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2001\11\17@081041 by Kathy Quinlan

flavicon
face
Hiya hon your link is dead :o(


Regards,

Kat.

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{Original Message removed}

2001\11\17@142121 by Jinx

face picon face
> Hiya hon your link is dead :o(
>
>
> Regards,
>
> Kat.
> >

Sorry petal

http://home.clear.net.nz/pages/joecolquitt/0bulblife.html

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2001\11\17@154258 by Jeff DeMaagd

flavicon
face
----- Original Message -----
From: Russell McMahon <@spam@apptechSTOPspamspam@spam@CLEAR.NET.NZ>

> Kathy,
>
> you are a prime candidate for a "fluorescent" bulb.
> These now sell regularly for $NZ10 here so should be similar there.
> A replacement fluro' bulb will require about 6 watts.

I've been liking flourescent bulbs as well.  I know there are those that
don't like the color but really that should be much of a factor as
flourescents are available in a wider range of colors than incandescents,
some of the direct screw-in replacements match the incandescent color and
appearance well enougn that many don't notice the difference, one I have has
negligible lighting lag, so I'll use that brand whenever I can.

Jeff

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2001\11\17@160220 by Jinx

face picon face
> I've been liking flourescent bulbs as well

It was a smart move changing to a fluorescent in my desk lamp. The
light is softer and I don't have a 100W filament burning me to a crisp

For bulbs around the house that couldn't be replaced with fluoros (as
fluoros are quite a bit longer) the ideal is series resistance + soft start,
which could be done easily with a 508

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2001\11\17@224152 by Alexandre Domingos F. Souza

flavicon
face
>> Hiya hon your link is dead :o(
>Sorry petal

       Hmmm...this has nothing to do with bulbs, but lets say the bright of bulb of love, when on, is beautiful ;o)

       Oh my...


---8<---Corte aqui---8<----

Alexandre Souza
spam_OUTtaitoSTOPspamspamterra.com.br
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2001\11\17@235442 by Jinx

face picon face
> Hmmm...this has nothing to do with bulbs, but lets say the bright
> of bulb of love, when on, is beautiful ;o)

>        Oh my...

Beg your pardon, Mr Pinballs 8-)

I didn't cross that line and say "pookie" he he

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2001\11\18@071524 by Jim

flavicon
face
Jinx -

Does your treatise mention the beneficial effect
using a BSR/X10 lamp module has on extending the
life of filament style lamps?

The *only* downside to the BSR/X10 lamp modules is
the RFI they produce that will affect 80/40 Meters
plus weaker broadcast stations on MW ...

Jim

{Original Message removed}

2001\11\18@095007 by Roman Black

flavicon
face
Jinx wrote:
>
> Anyone else see this on TV this week ? On the show I saw
> it on (World News Tonight with Peter Jennings) they had a
> view from below the bulb. The filament, quite by accident,
> spells "ON"
>
http://www.janeellen.com/musings/livermor.html


That's a cool bulb. And a lot of years!
-Roman

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2001\11\18@154929 by Jinx

face picon face
> Does your treatise mention the beneficial effect
> using a BSR/X10 lamp module has on extending the
> life of filament style lamps?

I don't know much about them - do they have a soft-start function ?

Resistors are a cheap readily-available alternative. Not ideal, but
worth the experiment. So far (10 months) I haven't lost any bulbs
when in a typical year I would have probably replaced all or most

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2001\11\18@155750 by Alexandre Domingos F. Souza

flavicon
face
>Resistors are a cheap readily-available alternative. Not ideal, but
>worth the experiment. So far (10 months) I haven't lost any bulbs
>when in a typical year I would have probably replaced all or most

       Hmmm, maybe a page with tipical wattages, and resistors? ;o)


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2001\11\18@160714 by Jinx

face picon face
>  Hmmm, maybe a page with tipical wattages, and resistors? ;o)

The only info I have is here

http://home.clear.net.nz/pages/joecolquitt/0bulblife.html

47R will get you in the ballpark for most domestic bulbs. You
can try others - keep an eye on resistor temperature and light
output

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2001\11\18@173341 by Russell McMahon

picon face
They are now selling 'fluro' bulbs in NZ in a more conventional round style
bulb. (I haven't laid eyes on one yet).


> For bulbs around the house that couldn't be replaced with fluoros (as
> fluoros are quite a bit longer) the ideal is series resistance + soft
start,
> which could be done easily with a 508

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