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#61
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Is there an updated Dynotest somewhere?
On 9/15/2017 10:03 AM, Joerg wrote:
On 2017-09-14 12:15, Frank Krygowski wrote: On 9/14/2017 10:26 AM, Ralph Barone wrote: bob prohaska wrote: Sepp Ruf wrote: For Rob who might experience mental drag uphill from just having to see a big, heavy, non-laminated hub slowly revolving in the front wheel, the smallish Shimano DH-T780-1N, 1.5W 250mA class, might suffice[1] once he grows sick of the Soubitez.Â* Best price I see is 96 euros a pair from CNC Hamburg on ebay, no overseas shipping available, though. http://www.ebay.com/itm/253093811841 [1] DRL does not require more than 100 lumens if you get the optics right. It's a bit puzzling how folks seem to excuse poor design in dynamo hubs when they're considerably more fanatic about optimizing every other part of a bicycle. In particular, the 3 watt standard is utterly archaic. Folks now are starting to use dynamos to power electronics, and I suspect most would opt for more than 3 watt lights if useful designs were available. I still don't understand why high-end builders like Schmidt don't use salient-pole armatures, which could be constructed from standard motor laminations (instead of the custom clawpole monolith used now). That would shorten the iron path dramatically, reducing reluctance, reduce the length of copper, reducing resistance. The performance gains can be traded for lighter weight, higher efficiency or higher power. Every motor builder in the world does it that way, why not dyamo hub builders? Maybe there _is_ a technical reason, but it certainly isn't apparent to me. The use of incandescent bulbs may have set the tradition, but it's certainly no reason to continue. At this rate I won't "get sick" of the Soubitez, I'll wear it out. bob prohaska Machine theory is a bit of a black art for me, but I suspect that the "less optimized" magnetics in hub dynamos provides the extra leakage inductance required to make it self regulate into a 12 ohm load. I fully agree that a less well regulated output plus a switching regulator could work very well with modern electronics. Is it feasible to use a switching regulator when you've got as much inductance as a typical hub dynamo? Yes. Â* I'd have thought that causes problems. Nope :-) But then, I'm not an EE. If charging a battery plus driving a light (which is the proper setup, like in a motor vehicle) it is advantageous to run the converter in "maxiumum power point tracking" or MPPT mode. That is what solar converters mostly do as well. A small processor dithers the "conversion factor" (input to output voltage) slightly around while constantly calculating the output power, indicating whether the maximum power point is drifting higher, lower, or remains constant. Mostly depending on riding speed in this case. When the load demand is met, the battery full and lights at full brightness, it has to back off in the direction of causing the least amount of mechanical load. The latter isn't a concern with solar panels. On a bicycle one would like a few more features, for example an uphill-disable that sheds the load unless the bus voltage is or becomes critically low. Another potential feature could be energy harvesting downhill by maximizing the power output during those times. 3-axis sensors could help determining such conditions automatically. Endless possibilities but, of course, there will come a point where it becomes "technology looking for a home" and more does not make sense. As usual don't expect to see this at bike shops anytime soon. You could add speed-based intensity of the light with the load shedding since when going slowly up hill you need less intensity, plus you want less load. Sort of OT but funny: Yesterday I stood at a red traffic light in the middle of the lane and my road bike started making a wee-wee. A puddle formed underneath the BB, meaning below where the saddle is ... embarrassing. Turns out my water bottle had developed a circumferential hair-crack. Oh no, now you're going to go off on a tangent about how no one make sturdy enough water bottles for you. |
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#62
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Is there an updated Dynotest somewhere?
On 9/15/2017 10:54 AM, Joerg wrote:
On 2017-09-14 12:26, Frank Krygowski wrote: On 9/14/2017 1:46 AM, bob prohaska wrote: Sepp Ruf wrote: For Rob who might experience mental drag uphill from just having to see a big, heavy, non-laminated hub slowly revolving in the front wheel, the smallish Shimano DH-T780-1N, 1.5W 250mA class, might suffice[1] once he grows sick of the Soubitez.Â* Best price I see is 96 euros a pair from CNC Hamburg on ebay, no overseas shipping available, though. http://www.ebay.com/itm/253093811841 [1] DRL does not require more than 100 lumens if you get the optics right. It's a bit puzzling how folks seem to excuse poor design in dynamo hubs when they're considerably more fanatic about optimizing every other part of a bicycle. In particular, the 3 watt standard is utterly archaic. Folks now are starting to use dynamos to power electronics, and I suspect most would opt for more than 3 watt lights if useful designs were available. Well, dynamos are not limited to 3 Watts. As James and others have discussed, they'll put out more power if presented with bigger loads, i.e. more resistance. Ummm, not quite. More resistance doesn't always mean bigger load, it only does so if you let the voltage rise. For any speed there is a resistance that will result in a maximum of the delivered electrical power. That resistance and the maximum power vary with speed. Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* ... They're essentially constant current devices. I used to occasionally drive two halogen headlamps from my Soubitez roller dynamo. Others do it with hub dynos. (It doesn't work well with a bottle dyno, though, because the smaller drive roller is more prone to slipping.) What happens is that the current isn't very constant. Many dynamos will go to 700mA and higher if you put the coals on. That was the reason I constantly blew light bulbs as a teenager until I finally "electronicized" my bikes and installed a recharcheable battery. Second, despite the current fashion for mega-lumen lights, I've seen no evidence that road cyclists need them, and I've seen the disadvantages. IME, a good B&M LED headlight lights up a stop sign nearly 1/4 mile way. It also illuminates the road very well; and with ever-improving LEDs, the current models are probably better than the ones I own. And it's a little ironic that the mega-lumen fans choose to ignore poor optical design in their headlights, leading to inferior illumination while blinding others. I think that's a bigger problem than a few percent less theoretical efficiency in the dynamo. There are people who disagree with you on that, such a yours truly. Finally, there are devices which will power a phone or a GPS unit from a hub dyno. Personally, I'd prefer to limit people from (say) playing their stereo speakers while they ride! My MP3 player is really helpful when riding boring stretches of prairie on the MTB or long lone climbs on the road bike. Plus it helps drown out the constant din of traffic when riding on roads. I used it for 2-1/2h of the 4h ride yesterday. And of course the fact that you're charging a phone doesn't meen that you're using it while you're riding. While the American River Trail is pretty quiet, there's some MUPs around here that are noisy from traffic. Los Gatos Creek Trail is next to CA 17 for a portion of it, and Stevens Creek Trail is near CA 85 for part of it. |
#63
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Is there an updated Dynotest somewhere?
On 2017-09-15 18:15, Frank Krygowski wrote:
On 9/15/2017 7:15 PM, Joerg wrote: On 2017-09-15 15:55, Frank Krygowski wrote: On 9/15/2017 4:01 PM, Joerg wrote: On 2017-09-15 12:43, Frank Krygowski wrote: The variation in brightess from, say, 6 mph to 20+ mph isn't really that great. But more important, when a person is riding uphill slowly, they don't need to see 1/4 mile ahead. Having a headlight that's slightly dimmer uphill is no disadvantage. Until the soused redneck in his dilapidated pickup truck comes tearing along and doesn't see you in time. Yeah, yeah - "Danger! Danger!" One of them just killed another cyclist here, from behind. This time it was an off-duty police office one the bike who died. Now you can stick you head back into the sand and pretend it doesn't happen. I thought we were talking about a drunk crossing to the wrong side of the road and hitting a person head-on because he was climbing a hill with a dynamo headlight. Don't pretend that's what happened. I didn't pretend but yes, that has also happened. Yes, I know that cyclists get killed by cars. That happens about 750 times per year. I also know that pedestrians get killed by cars, about 4500 per year, and motorists get killed in cars, about 35,000 per year. Don't stick your head in the sand, Joerg! Again, it's not only about those killed but also about a much larger number that survives. Some of which with what the med folks call life-changing injuries. Also: How often does that fantasy disaster happen anyway? Perhaps once in 500 million miles of riding? Just because you can imagine something, Joerg, it doesn't mean it's likely to happen. Roughly every month in NorCal. Every month some slow-climbing cyclist gets run over because his dynamo light is too dim? Baloney. No, cyclists get run over. Doesn't matter whether hill or not. A vehicle that travels at 1/4 the speed of motorized traffic or less is always at higher risk in the lane than traffic going at same speed. The risk goes up as the speed goes down. [...] -- Regards, Joerg http://www.analogconsultants.com/ |
#64
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Is there an updated Dynotest somewhere?
On 2017-09-15 19:48, John B. wrote:
On Fri, 15 Sep 2017 13:01:59 -0700, Joerg wrote: On 2017-09-15 12:43, Frank Krygowski wrote: On 9/15/2017 2:43 PM, Joerg wrote: On 2017-09-15 11:15, Frank Krygowski wrote: [...] ... This system is permanently mounted on the bike, just like the corresponding components on a car. It's ready at the flick of a switch and it's extremely reliable, requiring not even tending to batteries. How does it keep the lights at full brightness during a long uphill slog? Like some of these sections: https://ridewithgps.com/routes/5041564 The variation in brightess from, say, 6 mph to 20+ mph isn't really that great. But more important, when a person is riding uphill slowly, they don't need to see 1/4 mile ahead. Having a headlight that's slightly dimmer uphill is no disadvantage. Until the soused redneck in his dilapidated pickup truck comes tearing along and doesn't see you in time. But why should a "red neck" driving a pickup be soused? any more than a bicyclist? After all: https://cityroom.blogs.nytimes.com/2...eaths/?mcubz=1 Some 21 percent of autopsies for New York City bicyclists who died within three hours of their accidents detected alcohol in the body, according to a Department of Health and Mental Hygiene study that examined fatal bicycling accidents in New York City from 1996 to 2005. http://www.iihs.org/iihs/topics/t/pe...facts/bicycles Among bicyclists ages 16 and older who were killed in 2015, 23 percent had blood alcohol concentrations (BACs) at or above 0.08 percent. http://www.bhsi.org/alcohol.htm Blood alcohol levels were estimated from medical records, visits to crash sites and testing of 342 passing bicyclists for breath alcohol. At the .08 grams/deciliter level, legally drunk in most states, the odds of a fatal or serious injury rose by 2,000 per cent. The risk rose as alcohol rose, beginning at a 600 per cent increase if the blood level was only .02 grams/deciliter, equivalent to one drink. The .08 level is typically associated with four to five drinks. Sounds like it isn't the Redneck we have to look out for it is the drunken bicyclist. Drunken cyclists are a problem, especially since many people resort to a bicycle after losing their license due to DUI and then they don't really know how to handle a bicycle in traffic. However, I can't remember any of the hit-from-behind or hit-from-the-front fatal accidents here reported as being caused by a drunken cyclists. They were caused by drunken motorists, reckless ones, aggressive ones and people fleeing from police or a crime scene in a car. No matter, Frank can lament all day long, I know for a fact that since I have bright lights front and back the number of close calls has substantially dropped. So as far as lighting is concerned, mission accomplished. -- Regards, Joerg http://www.analogconsultants.com/ |
#65
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Is there an updated Dynotest somewhere?
On Saturday, September 16, 2017 at 7:34:30 AM UTC-7, Joerg wrote:
On 2017-09-15 18:15, Frank Krygowski wrote: On 9/15/2017 7:15 PM, Joerg wrote: On 2017-09-15 15:55, Frank Krygowski wrote: On 9/15/2017 4:01 PM, Joerg wrote: On 2017-09-15 12:43, Frank Krygowski wrote: The variation in brightess from, say, 6 mph to 20+ mph isn't really that great. But more important, when a person is riding uphill slowly, they don't need to see 1/4 mile ahead. Having a headlight that's slightly dimmer uphill is no disadvantage. Until the soused redneck in his dilapidated pickup truck comes tearing along and doesn't see you in time. Yeah, yeah - "Danger! Danger!" One of them just killed another cyclist here, from behind. This time it was an off-duty police office one the bike who died. Now you can stick you head back into the sand and pretend it doesn't happen. I thought we were talking about a drunk crossing to the wrong side of the road and hitting a person head-on because he was climbing a hill with a dynamo headlight. Don't pretend that's what happened. I didn't pretend but yes, that has also happened. Yes, I know that cyclists get killed by cars. That happens about 750 times per year. I also know that pedestrians get killed by cars, about 4500 per year, and motorists get killed in cars, about 35,000 per year. Don't stick your head in the sand, Joerg! Again, it's not only about those killed but also about a much larger number that survives. Some of which with what the med folks call life-changing injuries. Also: How often does that fantasy disaster happen anyway? Perhaps once in 500 million miles of riding? Just because you can imagine something, Joerg, it doesn't mean it's likely to happen. Roughly every month in NorCal. Every month some slow-climbing cyclist gets run over because his dynamo light is too dim? Baloney. No, cyclists get run over. Doesn't matter whether hill or not. A vehicle that travels at 1/4 the speed of motorized traffic or less is always at higher risk in the lane than traffic going at same speed. The risk goes up as the speed goes down. Doesn't matter whether the cyclist has a light or not. Doesn't matter whether the cyclist is in bed or watching TV. http://www.oregonlive.com/portland/i...e_in_sout.html Really, drunks will kill you in your dreams. And they're everywhere -- under your skin, whispering in your ear ". . . Joerg . . . Joerg . . . I'm coming for you." The only thing that will keep them away is a carbon-arc search light and an exorcism. You can get the light from Deal Extreme. Order today -- and talk to a Catholic priest. If you're a Lutheran, you're f*****. Might as well feed yourself to the mountain lions. -- Jay Beattie. |
#66
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Is there an updated Dynotest somewhere?
On 2017-09-16 06:57, sms wrote:
On 9/15/2017 10:03 AM, Joerg wrote: [...] If charging a battery plus driving a light (which is the proper setup, like in a motor vehicle) it is advantageous to run the converter in "maxiumum power point tracking" or MPPT mode. That is what solar converters mostly do as well. A small processor dithers the "conversion factor" (input to output voltage) slightly around while constantly calculating the output power, indicating whether the maximum power point is drifting higher, lower, or remains constant. Mostly depending on riding speed in this case. When the load demand is met, the battery full and lights at full brightness, it has to back off in the direction of causing the least amount of mechanical load. The latter isn't a concern with solar panels. On a bicycle one would like a few more features, for example an uphill-disable that sheds the load unless the bus voltage is or becomes critically low. Another potential feature could be energy harvesting downhill by maximizing the power output during those times. 3-axis sensors could help determining such conditions automatically. Endless possibilities but, of course, there will come a point where it becomes "technology looking for a home" and more does not make sense. As usual don't expect to see this at bike shops anytime soon. You could add speed-based intensity of the light with the load shedding since when going slowly up hill you need less intensity, plus you want less load. On a steep uphill I sure want my rear light as bright as it gets. On winding uphill stretches the risk of being seen too late is highest. As for speed input a hub dynamo provides that information because it delivers AC. So if bikes would have a real electrical system (though it's probably an illusion that ever happens ...) the ones with hub dynamos would no longer need the old magnetic pickup at the fork. Sort of OT but funny: Yesterday I stood at a red traffic light in the middle of the lane and my road bike started making a wee-wee. A puddle formed underneath the BB, meaning below where the saddle is ... embarrassing. Turns out my water bottle had developed a circumferential hair-crack. Oh no, now you're going to go off on a tangent about how no one make sturdy enough water bottles for you. To some extent true, the usually aren't MTB-proof. But cheap enough. The ones riding in the panniers are all stainless steel. -- Regards, Joerg http://www.analogconsultants.com/ |
#67
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Is there an updated Dynotest somewhere?
On 2017-09-16 07:01, sms wrote:
On 9/15/2017 10:54 AM, Joerg wrote: On 2017-09-14 12:26, Frank Krygowski wrote: [...] Finally, there are devices which will power a phone or a GPS unit from a hub dyno. Personally, I'd prefer to limit people from (say) playing their stereo speakers while they ride! My MP3 player is really helpful when riding boring stretches of prairie on the MTB or long lone climbs on the road bike. Plus it helps drown out the constant din of traffic when riding on roads. I used it for 2-1/2h of the 4h ride yesterday. And of course the fact that you're charging a phone doesn't meen that you're using it while you're riding. If I had a smart phone I'd be running it all the time, it would become the "cycling computer" and the map. Else I wouldn't really know what I'd need a smart phone for. My tiny "old-style" cell phone doesn't need charging since it runs over 100h per charge in receive-only mode. I use 30 "free" minutes per month and most of those keep piling up and up. While the American River Trail is pretty quiet, there's some MUPs around here that are noisy from traffic. Los Gatos Creek Trail is next to CA 17 for a portion of it, and Stevens Creek Trail is near CA 85 for part of it. Luckily most of ours aren't noisy, far enough away from traffic. My favorites are the singletrack paths where when you stop all you hear is the wind, the occasional call of an animal and maybe an airlines flying by at 40000ft. The only really noisy bike path I know around here is the one from Sacramento to Davis because it runs right along I-80: http://www.davisenterprise.com/files...W-1024x682.jpg -- Regards, Joerg http://www.analogconsultants.com/ |
#68
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Is there an updated Dynotest somewhere?
On 2017-09-16 07:51, jbeattie wrote:
On Saturday, September 16, 2017 at 7:34:30 AM UTC-7, Joerg wrote: On 2017-09-15 18:15, Frank Krygowski wrote: On 9/15/2017 7:15 PM, Joerg wrote: On 2017-09-15 15:55, Frank Krygowski wrote: [...] Also: How often does that fantasy disaster happen anyway? Perhaps once in 500 million miles of riding? Just because you can imagine something, Joerg, it doesn't mean it's likely to happen. Roughly every month in NorCal. Every month some slow-climbing cyclist gets run over because his dynamo light is too dim? Baloney. No, cyclists get run over. Doesn't matter whether hill or not. A vehicle that travels at 1/4 the speed of motorized traffic or less is always at higher risk in the lane than traffic going at same speed. The risk goes up as the speed goes down. Doesn't matter whether the cyclist has a light or not. Doesn't matter whether the cyclist is in bed or watching TV. http://www.oregonlive.com/portland/i...e_in_sout.html Really, drunks will kill you in your dreams. And they're everywhere -- under your skin, whispering in your ear ". . . Joerg . . . Joerg . . . I'm coming for you." There could also be a meteorite hit on the MUP. IIRC that almost happened ion Chelyabinsk, in Russia. Hopefully there was no MUP going through here :-) https://www.youtube.com/watch?v=xlVL8JRn9BI The only thing that will keep them away is a carbon-arc search light and an exorcism. You can get the light from Deal Extreme. Order today -- and talk to a Catholic priest. If you're a Lutheran, you're f*****. Might as well feed yourself to the mountain lions. Well, I am a Lutheran so I guess that's not going to work :-) -- Regards, Joerg http://www.analogconsultants.com/ |
#69
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Is there an updated Dynotest somewhere?
On 9/16/2017 10:34 AM, Joerg wrote:
No, cyclists get run over. Doesn't matter whether hill or not. A vehicle that travels at 1/4 the speed of motorized traffic or less is always at higher risk in the lane than traffic going at same speed. The risk goes up as the speed goes down. More bull****, Joerg, or at least, more ignorance of data. Motorcyclists have a fatality per hour rate roughly 30 times higher than bicyclists. You can't say that risk goes up as speed goes down. -- - Frank Krygowski |
#70
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Is there an updated Dynotest somewhere?
On 9/16/2017 10:46 AM, Joerg wrote:
No matter, Frank can lament all day long, I know for a fact that since I have bright lights front and back the number of close calls has substantially dropped. So as far as lighting is concerned, mission accomplished. And I can say precisely the same thing about my learning to ride more toward lane center, instead of at the road edge. I suppose if you are terrified enough to hide near the gutter, you may have a lot of close calls. That's pretty common. And I suppose glaring bright lights might reduce those gutter-induced close calls a bit. But riding more prominently as permitted by law does more, even though you refuse to understand this. See http://cyclingsavvy.org/2011/05/i-am-no-road-warrior/ and https://www.youtube.com/watch?v=yu5V...ature=youtu.be -- - Frank Krygowski |
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