Compact fluorescent lamp intensity?

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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 19 Mar 2008 21:47:18 -0700, Salmon Egg wrote:

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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
| 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 |
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
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.
Bill
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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]
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
|> |> 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 |
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
writes:

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
writes:

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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
----------------------------

------------------------- 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 snipped-for-privacy@shawcross.ca
remove the X to answer
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Salmon Egg wrote:

As far as I know, Commercial Electric is The Home Depot brand...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

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.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

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]
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.