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#61 |
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Guest
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> [snip]
>> Tim McNamara >>> Perhaps SMS should Google you to verify your expertise. > A Muzi <am@yellowjersey.org> >> Good idea! AltaVista says 'steven scharff light'= 24,300 results. >> 'adreas oehler light' = 16,400 results >> 'frank krygowski light' = 1,820 results >> 'tim macnamara light' = 44,100 results >> 'andrew muzi light' = 22,100 results >> 'carl fogel light' = 112,000 results >> 'peter white light' = 67 MILLION results >> (looks like Frank wins!) >> Some reader may draw meaning from that. I can't. carlfogel@comcast.net wrote: > I was impressed by my apparent expertise--112,000 hits! > > But then I googled for carl fogel light and found that Google confuses > me with hordes of karl fogels. > > (At least Google doesn't confuse carl with paul, which happens about > one time in ten in real life.) > > Forcing Google to respect my spelling preferences as "Carl Fogel" > reduces my expertise to about 1120 results for light. > > But most of those hits have to do with weight instead of illumination. > > I still think that this kind of light is superior to the new-fangled > electrified nonsense: > http://i29.tinypic.com/wjueli.jpg > http://i30.tinypic.com/2ikqz5c.jpg > http://i27.tinypic.com/24x2d86.jpg > http://i25.tinypic.com/9ppb2p.jpg I spend more time with acetylene than most people and that seems a reasonable approach to me. Sadly, I am not an expert by the present SMS standard - Alta Vista only shows 13 results for 'andrew muzi acetylene' -- Andrew Muzi <www.yellowjersey.org/> Open every day since 1 April, 1971 ** Posted from http://www.teranews.com ** |
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#62 |
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In article <VPu9k.11533$N87.6244@nlpi068.nbdc.sbc.com>,
SMS <scharf.steven@geemail.com> wrote: > Tim McNamara wrote: > > > Lots of other folks- Clive and Frank, just to name two- have told > > you that these simple systems work just fine. You're the one > > convinced that something approaching klieg lights are essential for > > commuting, and you're flat wrong. You've been told many times but > > you refuse to accept plain fact because it contradicts your > > beliefs. > > I prefer to believe the experts, since it jives with my own > experience. > > Type "expert dynamos" into the Google search bar, and click on "I'm > Feeling Lucky." I've collected the views of many lighting experts, > both individuals and organizatons, on that page. > > Here's some of them: > > Bicycle Federation of Wisconsin > (http://www.bfw.org/new_bfw/articles...?printable=true) > "Generators One of the oldest lighting systems is the generator. This > type of lighting works off a generator (or dynamo) that is powered > when it makes contact with the bicycle's tire. A generator system is > often set up to power a headlight and a taillight. These systems are > reliable, but often lack the power to really light up the road. > Generators are more popular in Europe than in the United States." Not written by an electrical or mechanical engineer. What makes this an "expert" opinion, other than that the author seems to as out of date as you are about dynamo systems? > Ken Kifer (http://www.kenkifer.com/bikepages/commute/accessor.htm) I > have been using generator lights for many years, and I find them very > suitable for riding in the country at night and on touring trips. > There are no batteries to fade or go bad, and the light gets brighter > while going downhill. The beam is very wide and thus visible from all > sides. On the other hand, a generator light is not very bright in > city traffic and goes out each time you stop at a red light. Mr. Keifer is most unfortunately deceased and his Web page, therefore, is also not up to date. > Peter Cole "I'm always surprised that so many serious cyclists who > otherwise recognize the equivalence of bicycles to other vehicles > take exception to lighting requirements. I wouldn't dare operate a > motorcycle with a 3W light, so I don't understand the recommendation > to operate a bicycle (at often similar speeds ) with such inadequate > lights. Perhaps this was an accommodation to the technological > limitations of the past, but in these times of readily available and > relatively cheap, high-wattage alternatives, it seems a bad way to > go." And once again the basis for considering this an expert opinion is that the author seems to agree with you. You see, the foundation of an expert opinion is that is comes from a person who knows the facts and has the requisite expertise to come to an accurate conclusion; it is not an opinion that agrees with your prejudices. Once again, I'd suggest that perhaps you should check out Andreas Oehler's credentials- which include being a mechanical engineer (gasp!) and working professionally in bicycle lighting (double gasp!). His opinion is- unlike yours or mine- an expert one. When it comes to opinions about dynamo powered bicycle lighting, Steven, Andreas knows what's up and you don't. It's as simple as that. You can continue to bluster on in arrogance and ignorance, or you can learn something and fix the plentiful errors of assumption and reasoning that are littered across your Web page and your posts. |
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#63 |
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A Muzi wrote:
> Good idea! AltaVista says 'steven scharff light'= 24,300 results. > 'adreas oehler light' = 16,400 results > 'frank krygowski light' = 1,820 results > 'tim macnamara light' = 44,100 results > 'andrew muzi light' = 22,100 results > 'carl fogel light' = 112,000 results > 'peter white light' = 67 MILLION results > > (looks like Frank wins!) > > Some reader may draw meaning from that. I can't. Maybe if my name was spelled correctly the results would be different. Since my bicycle lighting site is usually the #1 Google hit when searching for bicycle lighting, that probably skews the results quite a bit. No wonder people want to buy my domain name! |
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#64 |
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On Jun 28, 12:57 pm, SMS <scharf.ste...@geemail.com> wrote:
> > Those high power LEDs generate a tremendous > amount of waste heat, so almost every high power LED lamp will use > aluminum cases that act as a heat sink. Some technical questions for Stephen M. Scharf: How much waste heat is generated by a 3 Watt LED? How much waste heat is generated by a 3 Watt halogen bulb? How much waste heat is generated by a 10 Watt halogen bulb? We'll accept approximate answers. (Hint: Your answers should be measured in Watts.) - Frank Krygowski |
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#65 |
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On Jun 28, 5:02 pm, carlfo...@comcast.net wrote:
> > I still think that this kind of light is superior to the new-fangled > electrified nonsense: > http://i29.tinypic.com/wjueli.jpg > http://i30.tinypic.com/2ikqz5c.jpg > http://i27.tinypic.com/24x2d86.jpg > http://i25.tinypic.com/9ppb2p.jpg I own an antique, oil-burning bike headlight, complete with a shock- absorbing parallelogram linkage mount. I tried it one dark night, on a zero-traffic, heavily wooded road in our neighborhood. Feeble doesn't begin to describe it! I'm astounded that anyone ever used such a thing for night riding, even in 1890! - Frank Krygowski |
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#66 |
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On Jun 28, 5:23 pm, A Muzi <a...@yellowjersey.org> wrote:
> > I spend more time with acetylene than most people and that seems a > reasonable approach to me. > > Sadly, I am not an expert by the present SMS standard - Alta Vista only > shows 13 results for 'andrew muzi acetylene' You're not an expert by the SMS standard because you've disagreed with SMS! ;-) - Frank Krygowski |
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#67 |
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On Jun 28, 7:36 pm, SMS <scharf.ste...@geemail.com> wrote:
> > ... my bicycle lighting site is usually the #1 Google hit when > searching for bicycle lighting... Don't puff yourself up. Skill at search engine positioning doesn't make one an expert in bicycle lighting. - Frank Krygowski |
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#68 |
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"Frank Krygowski" <frkrygow@gmail.com> wrote in message
news:bbca50d3-c642-4786-8642-036183c4e93b@d45g2000hsc.googlegroups.com... > On Jun 28, 5:02 pm, carlfo...@comcast.net wrote: >> >> I still think that this kind of light is superior to the new-fangled >> electrified nonsense: >> http://i29.tinypic.com/wjueli.jpg >> http://i30.tinypic.com/2ikqz5c.jpg >> http://i27.tinypic.com/24x2d86.jpg >> http://i25.tinypic.com/9ppb2p.jpg > > I own an antique, oil-burning bike headlight, complete with a shock- > absorbing parallelogram linkage mount. I tried it one dark night, on > a zero-traffic, heavily wooded road in our neighborhood. > > Feeble doesn't begin to describe it! I'm astounded that anyone ever > used such a thing for night riding, even in 1890! I've used carbide lamps for caving, and they're quite nice and glowy. A pleasant all-round illumination, useless for bike riding - though my lamps didn't really have a reflector. They're also peril-sensitive, having an annoying tendancy to go out near waterfalls or pitches :-) cheers, clive |
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#69 |
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On Sat, 28 Jun 2008 16:53:03 -0700 (PDT), Frank Krygowski
<frkrygow@gmail.com> wrote: >On Jun 28, 5:02 pm, carlfo...@comcast.net wrote: >> >> I still think that this kind of light is superior to the new-fangled >> electrified nonsense: >> http://i29.tinypic.com/wjueli.jpg >> http://i30.tinypic.com/2ikqz5c.jpg >> http://i27.tinypic.com/24x2d86.jpg >> http://i25.tinypic.com/9ppb2p.jpg > >I own an antique, oil-burning bike headlight, complete with a shock- >absorbing parallelogram linkage mount. I tried it one dark night, on >a zero-traffic, heavily wooded road in our neighborhood. > >Feeble doesn't begin to describe it! I'm astounded that anyone ever >used such a thing for night riding, even in 1890! > >- Frank Krygowski Dear Frank, True, most old bicycling lamps resembled Playboy models--not necessarily bright, but darned good looking: "Despite the advertisement claims of power and reliability, the candle lamp gave very little light and, as the writer can confirm, is almost impossible to keep alight even in the lightest of breezes." http://www.websolutionswa.com/pwc/candle.asp Here's a parallelogram-mount oil light like the one that disappointed Frank: http://www.websolutionswa.com/pwc/oil/58.jpg It may not put out much light, but heads will turn when you roll past with that handsome contraption on your handlebar. That antique lighting site offers some history and huge galleries of the early oil, candle, acetylene, and electric bike lights: http://www.websolutionswa.com/pwc/ecl.asp A Dutch antique bike lighting site, with even more photos: http://home.tiscali.nl/antiekefietsverlicht/carbid.html A tail light could be connected to the front acetylene gas generator by a long tube, sometimes with exciting consequences: http://www.mvvcc.org.uk/features/lamps/lucas317.htm Cheers, Carl Fogel |
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#70 |
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SMS wrote:
> Doug McLaren wrote: >> On 2008-06-27, Doug McLaren <dougmc+usenet@frenzied.us> wrote: >> >> | For example, I've got a Cateye HL-EL 500 which they rate at 1000 >> | candlepower, they say it lasts 30 hours. It's quite bright. Assuming >> | that the 4 AA batteries are 2500 mAh (good alkalines), that's an >> | average of around 1/10th of a watt. >> >> I screwed up the math -- forgot that there's four AA's, not one. So >> it's about one half a watt, and probably goes down from there. I >> guess I should just measure it. Either way, it's pretty bright, >> though it certainly can't compare to the 15 watt halogen jobs I've >> seen. >> >> Good point that Mark made about the dynamo putting out AC -- but even >> with a 20% loss from a bridge rectifier and voltage regulator (perhaps >> one of the fairly efficient DC to DC converters?), it ought to be a >> big win if your new LED light is 3x as efficient as your old halogen >> light. > > The maximum efficiency of a bridge rectifier is 81.2%. A buck-boost > switching regulator will be about 80% efficient. So you're down to about > 65%. So my previous post was incorrect, it's not wasting 20%, it's > wasting 35%. Then you run into the problem that while the LED is more > efficient, it's more difficult to direct all the light to illuminate the > road, Sorry, that's not my experience nor that of many others making LED home-brews. Quite a variety of good, cheap optics are available. The ones I bought (http://www.ledsupply.com/20mm.php) work quite well. What you say may have been true about the older multi-LED lamps, but it isn't true of current "power" LEDs and their optics. Mark J. so for all the expense of the electronics to drive the LED you > haven't gained much over a simple incandescent bulb. |
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#71 |
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Mark wrote:
> What you say may have been true about the older multi-LED lamps, but it > isn't true of current "power" LEDs and their optics. There are newer LEDs coming that solve the problem by using two lenses. Ones lens collects the light emitted by the LED and combines it to form a beam. The secondary lens homogenizes the light beam. The problem with the current high power LEDs is that a lot of the light is wasted. You still have the issue that adjustable reflectors to do a wide/spot beam don't work well. Compare an LED MagLight to an incandescent MagLight in terms of the spot beam to wide beam adjustment. |
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