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#181
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Drop-in replacement LED bulbs?
On Dec 16, 12:11*pm, Chalo wrote:
SMS wrote: [BellSports] I guess Trek and Specialized are also anti-cyclist companies, LOL. Trek and Specialized haven't (to my knowledge) lobbied for laws that reduce participation in cycling and make it harder on those of us who remain. *I don't love them, but I don't havegoodreasons to avoid their products. Chalo Dear Chalo, http://www.newyorker.com/humor/issue...e=2#showHeader Cheers, Carl Fogel |
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#182
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Drop-in replacement LED bulbs?
Tom Sherman °_° wrote:
Andrew Muzi wrote: Minus five F again this morning. No crowds in my way just before dawn. Didn't see even one bicycle this morning. Even the one you were riding? Don't ... look ... down! Mark J. |
#183
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HELL MUTTS!
On 17 Dec, 04:57, Tom Sherman °_°
wrote: Paul Oosterhout wrote: Clive George wrote, On 12/16/2009 10:13 AM: "Paul O" wrote in message ... Chalo wrote, On 12/15/2009 7:38 PM: snip I used to get VistaLite 5-LED rear flashers because they used AAs. When I discovered that VistaLite was owned by the anti-cyclist company Bell Sports, I started buying Planet Bike blinky lights instead. *I don't prefer the AAA battery size, but in practice it does not seem to be a problem. Chalo Chalo, Mind if I ask why you consider Bell Sports to be an "anti-cyclist company". Is there something going on with Bell Sports that I'm not aware of? It's pretty obvious to anybody who's read these NGs for more than a couple of months. I think I know what you are getting at and I will just drop the matter here... We have not had a h*lm*t discussion in a while. They have been supplanted by foam caps. |
#184
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Drop-in replacement LED bulbs?
On Tue, 15 Dec 2009 17:00:01 -0800 (PST), Chalo
wrote: There is a critical difference. Incandescent bulbs radiate out most of their heat instead of retaining it in the device. And they are made of glass and metals that are relatively tolerant of high temperatures. An LED dumps all its heat within the semiconductor die, which can easily burn itself up if it does not have an adequate path through which to discharge waste heat. LEDs are damaged by relatively low temperatures-- for example, residual heat from soldering their leads can harm them if joints are not soldered quickly enough. I do actually know all this, I have a degree in electrical engineering. I also have LED front and rear lamps and don't recognise more than a tiny fraction of the issues Steven seeks to raise as insurmountable obstacles. Guy -- http://www.chapmancentral.co.uk/urc GPG public key at http://www.chapmancentral.co.uk/pgp-public-key.txt |
#185
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Drop-in replacement LED bulbs?
Chalo wrote:
Just zis Guy, you know? wrote: SMS wrote: In any case, I don't think anyone's touched on the biggest reason why it isn't practical to do drop-in replacements of a 3W LED to replace a 3W filament bulb. The 3W LEDs generate a large amount of heat at the semiconductor junction, and require very good heat sinks. Yes, it's well known that incandescent "bulbs" (lamps, Steven, they are called lamps) emit no heat whatsoever. There is a critical difference. Incandescent bulbs radiate out most of their heat instead of retaining it in the device. And they are made of glass and metals that are relatively tolerant of high temperatures. An LED dumps all its heat within the semiconductor die, which can easily burn itself up if it does not have an adequate path through which to discharge waste heat. LEDs are damaged by relatively low temperatures-- for example, residual heat from soldering their leads can harm them if joints are not soldered quickly enough. I think that LEDs got the reputation of generating no heat from low-power "being seen" LEDs. Non-engineers like Guy don't realize that an LED is actually a semiconductor with a junction. |
#186
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Drop-in replacement LED bulbs?
On Thu, 17 Dec 2009 21:04:06 -0800, SMS
wrote: Non-engineers like Guy don't realize that an LED is actually a semiconductor with a junction. Non-readers like SMS don't know what B.Eng (hons) MIET means. Guy -- http://www.chapmancentral.co.uk/urc GPG public key at http://www.chapmancentral.co.uk/pgp-public-key.txt |
#187
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HELL MUTTS!
We have not had a h*lm*t discussion in a while.
=v= So what? Unless somebody actually has something to say that hasn't already been spewed onto Usenet 100 times before, there's really not point. =v= And no, coming up with "Hell Mutts" because it wasn't yet in everyone's *plonk*files does NOT qualify as actually having something to say. It only qualifies as being obnoxious. _Jym_ |
#188
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HELL MUTTS!
Jym Dyer wrote:
We have not had a h*lm*t discussion in a while. =v= So what? Unless somebody actually has something to say that hasn't already been spewed onto Usenet 100 times before, there's really not point. It was tongue in cheek. =v= And no, coming up with "Hell Mutts" because it wasn't yet in everyone's *plonk*files does NOT qualify as actually having something to say. It only qualifies as being obnoxious. _Jym_ Boo hoo. -- Tom Sherman - 42.435731,-83.985007 I am a vehicular cyclist. |
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