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:I did redirect [[Light bulb]] to [[Lamp (electrical component)]]. The old redirect to this article is clearly not appropriate anymore; common usage of the term has broadened.--[[User:Srleffler|Srleffler]] ([[User talk:Srleffler|talk]]) 02:43, 8 November 2014 (UTC) |
:I did redirect [[Light bulb]] to [[Lamp (electrical component)]]. The old redirect to this article is clearly not appropriate anymore; common usage of the term has broadened.--[[User:Srleffler|Srleffler]] ([[User talk:Srleffler|talk]]) 02:43, 8 November 2014 (UTC) |
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:'''Note'': Srleffler and I are discussing what is the most common |
:'''Note''': Srleffler and I are discussing what is the most common usage of the term ''light bulb'', and therefore what is the [[WP:Primary topic]] for it, at [[Talk:Light bulb (disambiguation)]]; a [[WP:Permalink]] to that discussion is [https://en.wikipedia.org/w/index.php?title=Talk:Light_bulb_%28disambiguation%29&oldid=633140131 here.] [[User:Flyer22|Flyer22]] ([[User talk:Flyer22|talk]]) 03:18, 11 November 2014 (UTC) |
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== Short-lived bulbs == |
== Short-lived bulbs == |
Revision as of 03:19, 11 November 2014
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Efficiency and environmental impact
I've made the following changes to the first section of "efficiency and environmental impact"
- Clarify the difference between radiant luminous efficacy (LER) and source luminous efficacy (LES)
- Specify the values in the table that are LER and LES
- Removed the LER of "white light" as 240 lpw, since the white light source was not defined, and it REALLY must be.
- Removed the reference for the two idealized sources at 4000 and 7000 K, since it was not relevant to the values given. I believe the value for the 4000 K source is incorrect, it should be 8% and 55 lpw, but I have not changed the values.
- Corrected misuse of "efficiency"
- Replaced 3683 as the melting point of tungsten with 3695, as per theTungsten article.
PAR (talk) 04:44, 14 May 2012 (UTC)
This section begins with the statement "Approximately 90% of the power consumed by an incandescent light bulb is emitted as heat, rather than as visible light ..." This is at odds with the figures in the table below in this section and with the statement in the third paragraph of the introductory section that "most incandescent bulbs convert less than 5% of the energy they use into visible light." I've rewritten the sentence as "Of the power consumed by typical incandescent light bulbs, 95% or more is converted into heat rather than visible light ..." Piperh (talk) 17:55, 5 November 2013 (UTC)
- I think the confusion stems from the fact that the section jumps right into "luminous efficiency" and "efficacy" without first describing plain-old, straight-forward "conversion efficiency." Conversion efficiency is amount of total emitted radiation per the total electrical energy used. For a 120 volt, 100 watt, gas-filled lamp, this is about 10%, according to the books I've read.
- One of the problems is that nearly all the light --even visible light-- is eventually turned into heat energy. The only energy not wasted is the tiny amount that actually falls upon the retina. The rest just bounces around the room until it is all absorbed or flies out the window. It might be helpful to know where all the energy is all going, rather than saying it is just heat.
- As I understand it, the blackbody radiation from the filament is typically centered in the mid to far IR. The IR cut-off for the glass is typically around 1500 to 2000 nanometers, so any radiation longer than this wavelength is absorbed by the glass. The total conversion efficiency (total radiation output/watts) is indeed ~10%. (This includes UV, visible, and near-IR.) The rest of the radiation is absorbed by the glass and re-emitted as convection or radiation of a much lower wavelength. Some energy is also wasted as thermal conduction from the filament, or lost in the wiring and connections, or is just a victim of pure entropy. (Interestingly enough, I saw on Nova yesterday that a 120 volt, 100 watt incandescent bulb will put off the same amount of light when operated on just 12 volts, provided that the wiring is cryogenic superconductors.) It might be helpful to briefly explain something about conversion efficiency before defining luminous efficiency and efficacy, and explaining why it is lower (less than 5%). (Just a thought.) Zaereth (talk) 02:47, 7 November 2013 (UTC)
- It might also be useful to explain how lamps of higher wattage become more efficient. (If I remember correctly, beyond 1500 watts, incandecent lamps become much more efficient.) Also, if you live in cold environment, like mine, the emitted heat is not necessarily wasted, because it has a direct effect on my heating bill. Zaereth (talk) 02:57, 7 November 2013 (UTC)
"When used for lighting in houses and commercial buildings, the energy lost to heat can significantly increase the energy required by a building's air conditioning system, although during the heating season such heat is not all wasted, but is not as effective as the heating system." is a very biased characterization of the article cited. The article's author goes on to say "As always, of course, there are some exceptions that may just prove the rule. Most notably, as Paul Wheaton demonstrated in his excellent video on heating the person, not the house, task lighting using an incandescent bulb and a shade/reflector can act as a useful heat lamp, providing heat exactly where it is needed and not warming up the surrounding air. In fact, it's something I'm considering deploying in my own efforts to heat my home office efficiently." — Preceding unsigned comment added by 12.15.255.222 (talk) 19:35, 16 April 2014 (UTC)
Edit request on 5 November 2012
I wanted to edit it by myself, but page is protected. Please edit table "Comparison of efficacy by power" and include 230Volt light bulbs also. So one can compare differences between 120Volt and 230Volt lights sources. Dusan Hlavaty (talk) 09:48, 5 November 2012 (UTC)
- If you can provide the details for the alternative voltage bulbs which you wish to add - and a reliable source for the data, please reactivate this request, so that someone may add your information.
- Thanks. Begoon talk 10:54, 5 November 2012 (UTC)
EDIT: OK, I was trying to update "Comparison of efficacy by power" table like this: (All values are well known, because these bulbs are typically available in stores. I cannot find any reasonable source for other wattages like 35 Watt, 55 Watt, ...)
120 volt lamps[1] | 230 volt lamps[2] | |||
---|---|---|---|---|
Power (W) | Output (lm) | Efficacy (lm/W) | Output (lm) | Efficacy (lm/W) |
5 | 25 | 5 | ||
15 | 110 | 7.3 | ||
25 | 200 | 8.0 | 206 | 8.24 |
40 | 500 | 12.5 | 330 | 8.25 |
60 | 850 | 14.2 | 584 | 9.73 |
75 | 1,200 | 16.0 | ||
100 | 1,700 | 17.0 | 1,160 | 11.6 |
150 | 2,850 | 19.0 | ||
200 | 3,900 | 19.5 | 2,725 | 13.62 |
300 | 6,200 | 20.7 | 4,430 | 14.77 |
500 | 7,930 | 15.86 |
References
- ^ Wells, Quentin (2012), Smart Grid Home, p. 163, ISBN 1111318514, retrieved 2012-11-08
- ^ Roy, Kamesh (2006), Illuminating Engineering, p. 30, ISBN 8170088984, retrieved 2012-11-07
- Ok - thanks very much indeed for doing that. I'm going to leave this request open for others to comment on, though, because I'm not comfortable adding so much unsourced data (noting indeed that the original table is itself unreferenced.)
- I think I'd like to see some consensus that we should be adding more uncited data, and that it will improve the article to do so. I'm afraid I don't have enough information to know whether these numbers are reasonable or not, sorry.
- Thanks again for presenting all this - hopefully some other editors can share their opinions. Begoon talk 09:49, 6 November 2012 (UTC)
- If it helps for a reference, a chart showing 230V Incandescent lamp efficacy can be found in this book, Illuminating engineering on page 30. Zaereth (talk) 20:56, 7 November 2012 (UTC)
- You're welcome. For a ref for that, the numbers seem to very closely match the numbers in a chart found in this book, Smart Grid Home on page 163. However, the book doen't actually say what the input voltage is. I found a 1961 version of the IES Lighting Fundamentals Course which gives a similar chart, showing both 120 and 230V efficacy, on page 21, under a section titled, "Why is it preferable to operate incandescent lamps on 120-volt circuits rather than on higher voltage circuits?" It's almost identical to what we have here, but is not available on google books. All in all, I'd say we seem to have it right. Zaereth (talk) 00:28, 8 November 2012 (UTC)
- You're correct. I didn't read the paragraphs above the heading, but had almost mentioned something similar in my earlier comment, that is, nearly all incandescents are 120 volt. That, along with the similarity between his numbers and ours, seem to imply that the chart is indeed 120 volt. I think you've done a good job on our chart. If no one else has any objections, I'd be happy if you put the new chart into the article. (I'd do it myself, but am no good with graphics, templates, or other compuetr stuff.) Zaereth (talk) 01:38, 8 November 2012 (UTC)
- Done then, with this copy/paste edit. Thank you.
- Incidentally, I hate wikitables, they are horrid things, but I write a lot of code in my day job, so I can tolerate it. Begoon talk 02:04, 8 November 2012 (UTC)
How did these references get in, it is obvious they don't belong : ^ "Storey's guide to raising chickens" Damerow, Gail. Storey Publishing, LLC; 2nd edition (12 January 1995), ISBN 978-1-58017-325-4. page 221. Retrieved 10 November 2009. ^ "277 Secrets Your Snake and Lizard Wants you to Know Unusual and useful Information for Snake Owners & Snake Lovers" Cooper,Paulette. Ten Speed Press (1 March 2004), ISBN 978-1-58008-035-4. Page 161. Retrieved 10 November 2009. — Preceding unsigned comment added by 197.169.113.131 (talk) 16:30, 6 April 2013 (UTC)
I find it very curious (and I'm an EE) that efficiency is different for the same wattage bulb at different voltages (designed for that voltage), someone mentioned a reference above so maybe its plausible but an explanation would be appreciated. — Preceding unsigned comment added by 122.107.154.48 (talk) 06:55, 14 May 2013 (UTC)
To reply to the question above. I did not know this either, but I think the explanation is hinted at in the text of the article. 110V bulbs have thicker fillaments than 230V ones; this means that it takes longer for the filament to evaporate away and fail if desiged to operate at the same temperature. Alternatively, if the manufacuture designs for a similar lifetime instead, the 110V bulb can be designed for a higher filament temperature, which would mean higher efficiency. There might be an additional smaller effect due to an increased surface area of the thicker filament. Regards 86.157.124.41 (talk) 16:51, 28 July 2014 (UTC)
halogen efficacy sentence
"High-quality halogen incandescent lamps have higher efficacy, which will allow a halogen light to use less power to produce the same amount of light compared to a non-halogen incandescent light."
...would be more correct if 'high quality' removed.
While halogen is higher efficacy, they're mostly used in downlighter spotlight format, which results in much higher power being used for a given lighting job. 86.29.7.158 (talk) 08:05, 31 August 2014 (UTC)
- "High quality" might not be ideal wording, but it's not true that halogen lamps always have higher efficacy. The modern ones probably all do. Bulbs sold in many parts of the world five or ten years ago were typically optimized for longer life, and were not significantly more efficient than traditional incandescent bulbs.--Srleffler (talk) 22:35, 31 August 2014 (UTC)
life comparison
"Incandescent bulbs also have short lifetimes compared with other types of lighting; around 1000 hours for home light bulbs versus up to 10,000 hours for compact fluorescents and up to 100,000 hours for LED lamps."
ave vs max is a poor comparison. CFL is now ave 10k hrs, LED 20-35khrs
lighting LEDs don't have anywhere near the 50-100,00 hr life of indicator LEDs 86.29.7.158 (talk) 08:18, 31 August 2014 (UTC)
- Actual averages as measured in government or industry testing labs, or perhaps by consumer organizations, would be a better comparison that theoretical maximum lives for relatively new technologies. Also, the electronics in LED and CFL bulbs might fail early due to spikes in the electrical supply. Who can promise the utility will not provide any brief periods of high voltage, and there will be no instantaneous spikes from lightning or capacitor bank switching for some long span of years? In a commercial building I know well which installed higher efficiency lighting last year, about 1/4 of the LED bulbs died shortly after installation for unknown reasons. Certainly this is anecdotal, but it is not anecdotal that there are spikes in utility electric supply and that sometimes the voltage goes way above 130 (on a US 120 norm) for a while due to problems with tap changing transformers at substations or with regulators on the lines.. Another issue is heat. LEDs and CFLs do not like high temperatures which have no effect on incandescents. The newer bulbs may not do well as direct replacements in fully enclosed fixtures, or in locations which get extremely hot in summer. Any such susceptabilities could be tested but have they been reported? Edison (talk) 13:55, 31 August 2014 (UTC)
- 100,000 hours is 11 and a half years. It may take a while to get any long-term studies that uses actual averages. It might be best just to note those are theoretical averages for now. 75.76.68.167 (talk) 00:16, 4 September 2014 (UTC)
The usage of Carbon filament (edit | talk | history | protect | delete | links | watch | logs | views) has come up at a discussion at talk:carbon (fiber) -- 65.94.171.225 (talk) 03:41, 26 September 2014 (UTC)
Semi-protected edit request on 30 September 2014
The United States Patent Office gave a ruling 8 October 1883, that Edison's patents were based on the prior art of William Sawyer and were invalid. Litigation continued for a number of years. Eventually on 6 October 1889, a judge ruled[citation needed] that Edison's electric light improvement claim for "a filament of carbon of high resistance" was valid.
The court case references above, and where "citation needed" is listed, can be found in "Consol. Elec. Light Co v. McKeesport Light Co, 40 F. 21 (C.C.W.D. Pa. 1889) aff'd, 159 U.S. 465, 16 S. Ct. 75, 40 L. Ed. 221 (1895)." 152.33.134.39 (talk) 15:55, 30 September 2014 (UTC)
Fix reference in "Efforts to improve efficiency"
The reference for the sentence "However, later work indicated that initially promising results were in error." should be to this Applied Physics Letters errata: Addendum: “Three-Dimensional Photonic-Crystal Emitter For Thermal Photovoltaic Power Generation” [Appl. Phys. Lett.83, 380 (2003)], available at: http://scitation.aip.org/content/aip/journal/apl/86/24/10.1063/1.1941463
It took a fair bit of digging at both the Sandia website and also on archive.org to uncover the actual errata article. Victor Liu (talk) 18:06, 24 October 2014 (UTC)
Why Not a general page called light bulbs?
I have a fantastic picture for light bulbs, which pertain to the standard household light bulb you put in a socket. I just don't know where to put it because there is no page for light bulb/s. And not all of these are incandescent, the picture illustrates the progression of technologies of light bulbs. Rarely have I heard of the bulbs themselves called lamps unless you are referring to the small ones used in electronic devices.
— Preceding unsigned comment added by M jurrens (talk • contribs) 23:51, 7 November 2014 (UTC)
- The problem is that "light bulb" is a narrower term than "lamp". Several different kinds of lamp can be called a "light bulb", but not all types of lamp can. Right now we have the narrower article Incandescent light bulb, and the broader one on lamps in general. There isn't really a need for an article in between that covers only the types of lamp that can be called light bulbs.
- I did redirect Light bulb to Lamp (electrical component). The old redirect to this article is clearly not appropriate anymore; common usage of the term has broadened.--Srleffler (talk) 02:43, 8 November 2014 (UTC)
- Note: Srleffler and I are discussing what is the most common usage of the term light bulb, and therefore what is the WP:Primary topic for it, at Talk:Light bulb (disambiguation); a WP:Permalink to that discussion is here. Flyer22 (talk) 03:18, 11 November 2014 (UTC)
Short-lived bulbs
Regarding this edit, and its summary: It's not really clear that the primary reason for the lifetime of recent incandescent bulbs has anything to do with the cartel in the 1920's. There is a well-known tradeoff between bulb lifetime on the one hand, and light output and energy efficiency on the other. This article has a whole section on that topic. Manufacturers can make traditional incandescents with as long a life as one wants, but with the inevitable tradeoff that the bulbs would be dim and even more energy inefficient than a typical bulb. The famous centennial bulb has lasted so long partly because its light output is so low. It's a 60 W bulb that puts out about as much light as a 4 W night light.--Srleffler (talk) 01:52, 11 November 2014
- I agree, we'd need a pretty strong source before we start throwing the word "cartel" around. The lighting expert Don Klipstein covers this nicely in his website. A decrease in voltage can increase the lifetime dramatically, but at a cost in light output and efficiency. In essence, you could mount a resistor in line with the bulb to create a voltage drop. That would increase your lifetime, but still wouldn't save energy, because suddenly the resistor is generating heat but contributing no light. (e.g. You get an increase in lifetime for a decrease in light, with no energy savings.) The addition of gases over vacuum or halogen were all in a effort to try to increase both lifetime and output, trying to find that happy medium determined by supply and demand. Zaereth (talk) 02:55, 11 November 2014 (UTC)