16th Jan 2019, 2:31 pm | #61 | ||
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Re: The demise of the fluorescent tube
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Fluorescents and LEDs for lighting do have one thing in common - they both rely on fluorescence (in the fluorescent lamp it's excited by UV from mercury vapour, in the white LED it's by blue light emitted from a diode structure. So I daresay that all the work that the chemists did to make better phosphors has been used by the LED people. The effort hasn't been wasted! |
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16th Jan 2019, 4:01 pm | #62 | |
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Re: The demise of the fluorescent tube
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16th Jan 2019, 5:53 pm | #63 |
Heptode
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Re: The demise of the fluorescent tube
I might retrofit a flourescent tube light in my kitchen , but fit the modern led tube instead !
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16th Jan 2019, 6:18 pm | #64 |
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Re: The demise of the fluorescent tube
From pure curiosity, yesterday I saw one on-line outlet charging £60 per 8' tube (whilst another was charging £15- but a minimum order of 5 units)
Reading between the lines the message from the former outlet was apparent- if you want something this long and fragile, 'phone and negotiate a discount, then come and get it yourself. (..with a cardboard tube from a carpet warehouse) Fair enough really. I can't remember the last time i shifted an 8 footer without clonking it against something- and wow, are they stronger than they look! Dave |
16th Jan 2019, 6:38 pm | #65 | |
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Re: The demise of the fluorescent tube
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16th Jan 2019, 7:00 pm | #66 |
Nonode
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Re: The demise of the fluorescent tube
A lot of those expensive professional makeup lighted mirrors use the small circle tubes, so I wonder if a viable replacement is available?
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16th Jan 2019, 7:12 pm | #67 |
Octode
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Re: The demise of the fluorescent tube
I'm wondering if that's just at the store you went to, as I can still get the regular tubes and fittings from the usual places around here.
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16th Jan 2019, 9:30 pm | #68 |
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Re: The demise of the fluorescent tube
A few months ago I bought a selection of GU 10 LED lamps of various beam angles and wattages for a new outside light. Those by Pro -electric flickered, those by V-Tac and Megaman did not. Interestingly, in very small print, the boxes of the V-Tac lamps warn that they should only be used for 10-12 hours daily, and that usage for 24 hours would void the respective 2 and 5 years warranties. Just.as well I will not be using them in a "Dawn to dusk" application where they would have to operate for more than 12 hours per day for around half the year. Both have a nominal 30,000 hrs life, and 5 years is more than this, but 2 years is only about half this on my rough calculations. The other makers do not mention any limits on daily use.
Last edited by emeritus; 16th Jan 2019 at 9:37 pm. |
16th Jan 2019, 10:25 pm | #69 |
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Re: The demise of the fluorescent tube
Sylvania 'Activa' tubes were a little disappointing. More expensive than the standard article (cos of multiple phosphor layers presumably)
Claim 5,300k but it comes across as a slightly sickly light green. Less efficient as well; on the alpha efficiency scale we are used to seeing they were given a B when the other T8's had an A. I might give them another try from the SAD point of view before condemning them, but i'm not convinced. Dave |
16th Jan 2019, 10:33 pm | #70 |
Octode
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Re: The demise of the fluorescent tube
Kalee20. "Surely 6000K is warmer than 4000K?". I've never thought of it that way but I sort of see where you are coming from! The warmer a black body gets, the higher frequency the radiation will be, so nearer to the 'blue' end of the spectrum.
In human terms though, we perceive warm to be at the red end of the spectrum which is where the heat from the fire is! The Philpott. 8' tubes were discontinued many years ago but seem to still be readily available but at insane prices! I still have a stock of them and in fact changed two last weekend in a factory. Considering how thin the glass is, they are amazingly strong- I too have whacked them while carrying them and not broken any! I have another few to replace for another customer next week. I believe there used to be a 10 foot tube, but I've never seen one! Sinewave. " I'm wondering if that's just at the store you went to ". This is a large electrical wholesaler to the trade where I've had an account for some years. A big chunk of the local trade will shop there, so if they are no longer stocking fluorescent, it's a fair bet that other retailers will follow suit in the near future. Well, I've taken the plunge! I have a 5 foot LED fitting to install in the guy's tea room at the weekend. It's a 40 foot 'Portakabin' and has two other 5' fluorescents in there already. I'll be interested in how the new fitting compares! Watch this space! All the best Nick |
16th Jan 2019, 11:23 pm | #71 |
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Re: The demise of the fluorescent tube
Every discussion forum needs to have a focus, otherwise it ends up with discussions about anything which peter out into discussions about nothing. And then it starts losing readers. The Internet is a big enough place already. If you want to talk about cars, then do so in your own bit of it. Links to private blogs are allowed here, and almost certainly preferred to off-topic posts.
Back on topic: LEDs are a technology I have seen mature in my own lifetime; from dim red indicator dots in the early 1970s, progressing through the spectrum in the 80s to blue and violet by the 1990s, and getting brighter with each iteration. The colour rendering has also improved vastly since the early bluish whites. I'm replacing my CFLs with LEDs one by one as they fail; but it's going to be a rather slower process than the original process of replacing the original tungsten filament bulbs with CFLs!
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17th Jan 2019, 12:37 am | #72 |
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Re: The demise of the fluorescent tube
All my CFL's are sitting in a box in the loft, wondering what the hell happened.
'the lamps in this luminaire cannot be renewed' for LED fitments is a retrograde step ecologically and i hope that the ES/BC sockets will go on and on. (Sooner or later someone will crow that they are hazardous- but if someone wants to stick their finger in a light socket perhaps there isn't much hope for them in the long term..?) I have just found a pair of 125w tubes in the loft- perhaps i will get a suntan this year after all. |
17th Jan 2019, 1:28 am | #73 |
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Re: The demise of the fluorescent tube
I can certainly see CFLs disappearing from general sale soon. Even people who don't mind them are likely to have a lifetime's supply of the things in a box somewhere, and will never need to buy another new one. Quite apart from the vast quantities sent out by the energy companies, you often see bags of them put out by the roadside by people who have switched to LEDs.
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17th Jan 2019, 10:02 am | #74 | |
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Re: The demise of the fluorescent tube
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So why aren't LED replacements made with detachable control circuitry like the industrial specced-CFLs, conventional fluorescent tubes and other discharge lamps are / were?
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17th Jan 2019, 12:41 pm | #75 |
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Re: The demise of the fluorescent tube
Probably down to manufacturing cost. A two-part lamp with a detachable, customer-replaceable, light-emitting element would need a connector that would increase its cost. I remember when I was with Plessey that you could get a complete Shure cartridge for your Garrard deck from the staff sales shop for considerably less than the cost of a replacement stylus from a record shop. By the time you have factored in the middleman's costs, there would probably be little retail price difference between a one part lamp and half of a two-part lamp.
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17th Jan 2019, 4:23 pm | #76 |
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Re: The demise of the fluorescent tube
There would also be compatibility and customer confusion issues, because every manufacturer would have different connector types, and variations of those for different lumen levels etc. It would also make the overall unit bigger to accommodate the connector. They would also need to design the power supply part to not fail if run with no load.
When it stopped working the customer would have to somehow work out which part needed replacing, find and purchase that (if still available), fit it together and hope for the best. Chances are they would buy the wrong part, or a different brand or lumen level and it wouldn't fit or wouldn't work. When the whole lamp only costs about £2 it just isn't worth the bother. It is a single replaceable item like the filament and CFL bulbs they replace, and in reality they are reasonably reliable and long lasting, even if they don't achieve the claimed 25,000 hours or whatever.... if anyone is counting! |
17th Jan 2019, 5:24 pm | #77 |
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Re: The demise of the fluorescent tube
True. And even with the BC CFL's, you have to place the whole plug-in item when it stops working. You can't replace just the tube, or just the power supply, if that fails.
Traditional fluorescent lamps, you can replace just the tube, or just the starter. In principle, you could replace the choke, or the power-factor correction capacitor (if fitted), but I've never heard of anyone doing so - they just replace the whole fitting. |
17th Jan 2019, 5:25 pm | #78 | |
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Re: The demise of the fluorescent tube
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But it is! It's no good folks bleating on about the environmental impact of the end product in their homes or industries when they're turning a blind eye to the cost of manufacturing and carbon impact it has. Oh, OK then - a balance has to be struck. The cost of producing an incandescent lamp from some sand, a paltry sheet of tin and a bit of tungsten is environmentally cheap but the cost of running it far outweighs any production costs. So a similar balance must be struck between churning out capacitors or other components, plastic (currently deemed the enemy) and the cost at the other end of running the things. But it's certainly not insurmountable.
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17th Jan 2019, 5:29 pm | #79 | |
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Re: The demise of the fluorescent tube
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The thing is money could be saved in the long term if domestic consumer products were designed along the same lines as those used in industry.
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17th Jan 2019, 5:35 pm | #80 |
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Re: The demise of the fluorescent tube
If I could find a long term reliable LED lamp I would be happy to spend a bit more, all so far are the same cheap construction and component quality. Poundland do good 5W ones that (so far) have outlived some £8 Philips ones.
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