Electrical Engineering - Compact fluorescent lamp intensity?

Author

Compact fluorescent lamp intensity?

Salmon Egg

2008-03-20, 3:25 am

I bought a PAR (parabolic reflector) compact fluorescent lamp (CFL) that
is supposed to producer light equivalent to that of a 100W incandescent
lamp. It is easy to see the coiled nature of the tube itself insed the
envelope.

The turn-on is virtually instantaneous,but at a low output level. My
uncalibrated eyeball estimates no more than 10% of the ultimate light
output. After about two minutes the lamp gets to be about where I would
expect it to be.

What is happening? If it is a matter of warming up the lamp sufficiently
to get the proper mercury pressure, why do I not seem the effect with
other CFL's?

Bill

James Sweet

2008-03-20, 3:25 am

"Salmon Egg" <SalmonEgg@sbcglobal.net> wrote in message
news:SalmonEgg-A39159.21471819032008@news.la.sbcglobal.net...
>I bought a PAR (parabolic reflector) compact fluorescent lamp (CFL) that
> is supposed to producer light equivalent to that of a 100W incandescent
> lamp. It is easy to see the coiled nature of the tube itself insed the
> envelope.
>
> The turn-on is virtually instantaneous,but at a low output level. My
> uncalibrated eyeball estimates no more than 10% of the ultimate light
> output. After about two minutes the lamp gets to be about where I would
> expect it to be.
>
> What is happening? If it is a matter of warming up the lamp sufficiently
> to get the proper mercury pressure, why do I not seem the effect with
> other CFL's?
>
> Bill

This occurs with mercury amalgam lamps as they have to warm up until the
mercury vapor pressure is sufficient. Lamps employing metallic mercury will
warm up faster, but cannot achieve the power density of the amalgam lamps.

2008-03-20, 9:25 am

On Wed, 19 Mar 2008 21:47:18 -0700, Salmon Egg wrote:

> I bought a PAR (parabolic reflector) compact fluorescent lamp (CFL) that
> is supposed to producer light equivalent to that of a 100W incandescent
> lamp. It is easy to see the coiled nature of the tube itself insed the
> envelope.
>
> The turn-on is virtually instantaneous,but at a low output level. My
> uncalibrated eyeball estimates no more than 10% of the ultimate light
> output. After about two minutes the lamp gets to be about where I would
> expect it to be.
>
> What is happening? If it is a matter of warming up the lamp sufficiently
> to get the proper mercury pressure, why do I not seem the effect with
> other CFL's?
>
> Bill

Yep, mine does the same. I have a kitchen overhead that takes about 5
minutes to come to full brightness. I also have one in the stairwell to
the basement. It is a piece of crap. I need the instant on like in a
normal lightbulb. I don't want to have to wait 5 minutes for the ****
thing to warm up when I need to go down there.

Al

phil-news-nospam@ipal.net

2008-03-20, 9:25 pm

On Thu, 20 Mar 2008 13:51:44 GMT Al <no.spam@wanted.com> wrote:
| On Wed, 19 Mar 2008 21:47:18 -0700, Salmon Egg wrote:
|
|> I bought a PAR (parabolic reflector) compact fluorescent lamp (CFL) that
|> is supposed to producer light equivalent to that of a 100W incandescent
|> lamp. It is easy to see the coiled nature of the tube itself insed the
|> envelope.
|>
|> The turn-on is virtually instantaneous,but at a low output level. My
|> uncalibrated eyeball estimates no more than 10% of the ultimate light
|> output. After about two minutes the lamp gets to be about where I would
|> expect it to be.
|>
|> What is happening? If it is a matter of warming up the lamp sufficiently
|> to get the proper mercury pressure, why do I not seem the effect with
|> other CFL's?
|>
|> Bill
|
| Yep, mine does the same. I have a kitchen overhead that takes about 5
| minutes to come to full brightness. I also have one in the stairwell to
| the basement. It is a piece of crap. I need the instant on like in a
| normal lightbulb. I don't want to have to wait 5 minutes for the ****
| thing to warm up when I need to go down there.

Maybe the NEC needs to specify that an installation on a stairway not only
must have a switch at each end, but must also be done in such a way that
only instant-on lights can be installed.

I don't put CFLs where light is critical. Most of mine are outdoors. I do
see a bit of a warm up problem is cold weather outdoors.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2008-03-20-2034@ipal.net |
|------------------------------------/-------------------------------------|

Don Kelly

2008-03-21, 3:25 am

----------------------------
"Salmon Egg" <SalmonEgg@sbcglobal.net> wrote in message
news:SalmonEgg-A39159.21471819032008@news.la.sbcglobal.net...
>I bought a PAR (parabolic reflector) compact fluorescent lamp (CFL) that
> is supposed to producer light equivalent to that of a 100W incandescent
> lamp. It is easy to see the coiled nature of the tube itself insed the
> envelope.
>
> The turn-on is virtually instantaneous,but at a low output level. My
> uncalibrated eyeball estimates no more than 10% of the ultimate light
> output. After about two minutes the lamp gets to be about where I would
> expect it to be.
>
> What is happening? If it is a matter of warming up the lamp sufficiently
> to get the proper mercury pressure, why do I not seem the effect with
> other CFL's?
>
> Bill
-------------------------
I have some that take some time to come up to normal brightness while others
appear to quite fast. The faster ones are a newer style- more compact so
there may have been some modifications that help with this.-or it may be the
particular brand.
--

Don Kelly dhky@shawcross.ca
remove the X to answer

Salmon Egg

2008-03-21, 3:25 am

In article <frv3h142674@news3.newsguy.com>, phil-news-nospam@ipal.net
wrote:

> Maybe the NEC needs to specify that an installation on a stairway not only
> must have a switch at each end, but must also be done in such a way that
> only instant-on lights can be installed.

This gets me back to a subject I posted on several years back.
Fluorescent glow tube starters, if you can find them, need ambient light
to start. They certainly would be useless in a totally dark environment!
The old ones probably had sufficient radioactive material or some other
"defect" that allowed them to start in total darkness.

Bill

Salmon Egg

2008-03-21, 3:25 am

In article <sQFEj.100936$pM4.68582@pd7urf1no>,
"Don Kelly" <dhky@shaw.ca> wrote:

> I have some that take some time to come up to normal brightness while others
> appear to quite fast. The faster ones are a newer style- more compact so
> there may have been some modifications that help with this.-or it may be the
> particular brand.

Almost all CFL's that I have seen are distributed by FEIT. Most probably
come from China. These include those that brighten up quickly as well
the slow ones. The slow ones are all from the one pack of PAR lamps.

I had a problem with their reliability as well. One burned out in about
eight months. Another in about eight minutes. The third is still running
although it has been less than a year. I contacted FEIT and they
replaced them quickly with no fuss.

Bill

James Sweet

2008-03-21, 3:25 am

"Salmon Egg" <SalmonEgg@sbcglobal.net> wrote in message
news:SalmonEgg-D0244D.21113020032008@news.la.sbcglobal.net...
> In article <frv3h142674@news3.newsguy.com>, phil-news-nospam@ipal.net
> wrote:
>
>
> This gets me back to a subject I posted on several years back.
> Fluorescent glow tube starters, if you can find them, need ambient light
> to start. They certainly would be useless in a totally dark environment!
> The old ones probably had sufficient radioactive material or some other
> "defect" that allowed them to start in total darkness.
>

Modern ones will work just fine in total darkness too. Sometimes they get a
bit weak as they age, or in cases of very low line voltage they might have
difficulty, but they are readily available and certainly work in total
darkness.

James Sweet

2008-03-21, 3:25 am

>
> Almost all CFL's that I have seen are distributed by FEIT. Most probably
> come from China. These include those that brighten up quickly as well
> the slow ones. The slow ones are all from the one pack of PAR lamps.
>
> I had a problem with their reliability as well. One burned out in about
> eight months. Another in about eight minutes. The third is still running
> although it has been less than a year. I contacted FEIT and they
> replaced them quickly with no fuss.
>

About 1/3 of the CFLs I've had are made by Feit, other common ones are
Commercial Electric and Megaman. As far as I know, *all* currently produced
CFLs are made in China, even GE moved production there.

Lifespan has been hit or miss for me, some fail very quickly, but if they
make it past the first week or so they usually last a long time. The longest
lasting ones are those I have in dusk till dawn service outside.

The floods are all amalgam lamps because the enclosed tube operates at a
much higher temperature and greater temperature swing than exposed tubes,
hence the slow warmup. Tubes with liquid mercury in them have trouble
maintaining correct vapor pressure if operated in an enclosed fixture.

Salmon Egg

2008-03-21, 1:25 pm

In article <sOIEj.8626$SF2.4298@trndny03>,
"James Sweet" <jamessweet@hotmail.com> wrote:

> Modern ones will work just fine in total darkness too. Sometimes they get a
> bit weak as they age, or in cases of very low line voltage they might have
> difficulty, but they are readily available and certainly work in total
> darkness.

Fortunately, I no longer have much need for glow tube starters. But from
time to time I look at them when I am at a place like Home Depot or a
hardware store. Last time I looked, the aluminum had holes in them to
let light in. I have also gone into dark rooms where lamps did not start
and shined a flashlight onto the starter. Then, they start quickly each
time. I'll look again.

Bill

Salmon Egg

2008-03-21, 1:25 pm

In article <USIEj.12423$FK1.10635@trndny08>,
"James Sweet" <jamessweet@hotmail.com> wrote:

> About 1/3 of the CFLs I've had are made by Feit, other common ones are
> Commercial Electric and Megaman. As far as I know, *all* currently produced
> CFLs are made in China, even GE moved production there.
>
> Lifespan has been hit or miss for me, some fail very quickly, but if they
> make it past the first week or so they usually last a long time. The longest
> lasting ones are those I have in dusk till dawn service outside.
>
> The floods are all amalgam lamps because the enclosed tube operates at a
> much higher temperature and greater temperature swing than exposed tubes,
> hence the slow warmup. Tubes with liquid mercury in them have trouble
> maintaining correct vapor pressure if operated in an enclosed fixture.

Thanks for the interesting information.

I do not remember seeing lamps from Commercial Electric or Megaman
around here (Los Angeles area).

Is there more you can tell us about the amalgam construction?

Bill

Anthony Guzzi

2008-03-21, 8:25 pm

Salmon Egg wrote:
> In article <USIEj.12423$FK1.10635@trndny08>,
> "James Sweet" <jamessweet@hotmail.com> wrote:
>
>
> Thanks for the interesting information.
>
> I do not remember seeing lamps from Commercial Electric or Megaman
> around here (Los Angeles area).
>
> Is there more you can tell us about the amalgam construction?
>
> Bill

As far as I know, Commercial Electric is The Home Depot brand...

James Sweet

2008-03-21, 9:25 pm

"Anthony Guzzi" <dukeofurl@sonic.net> wrote in message
news:47e43ad0$0$36346$742ec2ed@news.sonic.net...
> Salmon Egg wrote:
>
>
> As far as I know, Commercial Electric is The Home Depot brand...

And Megaman is sold by Ikea, but I'm sure you can get them other places.

As for the differences between pure mercury and amalgam lamps, there's very
little difference in the construction of the lamp itself, however the
standard type has a tiny blob of pure metallic mercury inserted into the
tube which vaporizes into the mercury vapor excited to produce UV light to
excite the phosphor, while amalgam lamps have a pellet of mercury amalgam,
an alloy of mercury and another metal. The pure mercury lamps will warm up
much more quickly, but light output will vary considerably more with
temperature of the tube and hence mercury vapor pressure.

Andrew Gabriel

2008-03-25, 3:25 am

In article <SalmonEgg-496ADF.11130521032008@news.la.sbcglobal.net>,
Salmon Egg <SalmonEgg@sbcglobal.net> writes:
>
> Is there more you can tell us about the amalgam construction?

The amalgam absorbs and releases mercury to maintain the correct
mercury vapor pressure over a temperature range, and over the
life of the lamp where mercury is permanently lost by absorbtion
into the other parts of the lamp such as the phosphor, glass, and
filaments. AFAIK, amalgams were first used to regulate the mercury
pressure in high pressure sodium lamps. They started finding their
way into compact fluorescents where the tube operating temperature
was both much higher and more variable than tradition linear
fluorescents. The amalgam has a thermal inertia (and possibly
also a delay on getting the mercury to the surface and evaporated),
and the mercury has to travel the tube, hence the run-up time to
produce full output.

It should be noted that even old traditional fluorescent tubes
have a run-up time to full output. However, their initial light
output is a higher proportion of their final light output and the
run-up was often not noticed.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

Andrew Gabriel

2008-03-25, 9:25 am

In article <SalmonEgg-D0244D.21113020032008@news.la.sbcglobal.net>,
Salmon Egg <SalmonEgg@sbcglobal.net> writes:
>
> This gets me back to a subject I posted on several years back.
> Fluorescent glow tube starters, if you can find them, need ambient light
> to start. They certainly would be useless in a totally dark environment!

That would seem to be a 120V mains problem.
Doesn't exist in 240V mains countries.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

phil-news-nospam@ipal.net

2008-03-25, 9:25 am

On 25 Mar 2008 10:38:53 GMT Andrew Gabriel <andrew@a20> wrote:
| In article <SalmonEgg-D0244D.21113020032008@news.la.sbcglobal.net>,
| Salmon Egg <SalmonEgg@sbcglobal.net> writes:
|>
|> This gets me back to a subject I posted on several years back.
|> Fluorescent glow tube starters, if you can find them, need ambient light
|> to start. They certainly would be useless in a totally dark environment!
|
| That would seem to be a 120V mains problem.
| Doesn't exist in 240V mains countries.

They should have connected fluorescent lights line-to-line in North America.

That way it would be 240 volts. And 240 volt ballasts are available. But
people were just too cheap to spring for a double pole switch, so they put
in those starters instead. Which was cheaper? Adding the starter or the
difference between a single pole and double pole switch.

For those outside North America (and those inside who don't understand the
electrical system), we do have 240 volt service. But it comes as two sides
of a transformer which is tapped in the middle for ground reference. So
there are two line wires coming into the house, along with the neutral.

And the voltage relative to ground is only 120 volts on either line wire.

Wiring things like the screw in bulb socket line-to-line would be unsafe.
But most other things would be fine wired line-to-line as long as they are
able to handle 240 volts and have a double pole switch to interrupt both
wires at the same time.

--
|---------------------------------------/----------------------------------|
| Phil Howard KA9WGN (ka9wgn.ham.org) / Do not send to the address below |
| first name lower case at ipal.net / spamtrap-2008-03-25-0843@ipal.net |
|------------------------------------/-------------------------------------|

James Sweet

2008-03-25, 1:25 pm

"Andrew Gabriel" <andrew@a20> wrote in message
news:47e8d63d$0$633$5a6aecb4@news.aaisp.net.uk...
> In article <SalmonEgg-D0244D.21113020032008@news.la.sbcglobal.net>,
> Salmon Egg <SalmonEgg@sbcglobal.net> writes:
>
> That would seem to be a 120V mains problem.
> Doesn't exist in 240V mains countries.
>

Anything over 2' in 120V land uses an autotransformer ballast anyway, so the
voltage across the starter is approximately the same as it is with a 240V
choke ballast. That said, starters haven't been used on anything over 2'
since probably the late 1960s when rapid start became common. I still kinda
like the way the old preheat starters make the lamps flicker and flash when
you turn them on.

daestrom

2008-03-25, 5:25 pm

"James Sweet" <jamessweet@hotmail.com> wrote in message
news:wU9Gj.2343$Ew5.2292@trnddc04...
>
>
> "Andrew Gabriel" <andrew@a20> wrote in message
> news:47e8d63d$0$633$5a6aecb4@news.aaisp.net.uk...
>
>
> Anything over 2' in 120V land uses an autotransformer ballast anyway, so
> the voltage across the starter is approximately the same as it is with a
> 240V choke ballast. That said, starters haven't been used on anything over
> 2' since probably the late 1960s when rapid start became common. I still
> kinda like the way the old preheat starters make the lamps flicker and
> flash when you turn them on.

Don't know what the problem with starters is. I've used quite a few in my
day, in total darkness on 120V and they start just fine. (and believe me, it
can get pretty dark in a submarine :-) )

On the other hand, the 'rapid start' ones from some years back have a
problem starting if the fixture isn't properly grounded. Had a shop light
that wouldn't start until I held my hand up near it (not touch it, just get
within about six inches).

daestrom

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