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DynoHubs: What light bulbs/LED emitters?
What light bulbs/LED emitters are you powering with your
Sturmey-Archer Dynohub? Front? Back? I did the thing with the bridge rectifier to convert it's output to DC - figuring I'd drive some LED emitters to get max light. But I'm having problems with the voltage regulator part. I get the circuit tuned to put out, say, 1.5 volts with 6 volts coming in from a 4-battery test source and then when I put another battery in series, the output voltage rises to 2.something. Probably something dumb I'm doing in the regulator, and I expect to do it right eventually. But it got me to wondering how voltage-tolerant light bulbs and LEDs are. My assumption going into this has been "not very", but I don't have much to base that on. Am I doing the voltage regulation piece in vain? Do I really need regulation? When I hang a voltmeter on the DC output it varies from 3 volts at a walking pace to about 20 volts on a downhill. So, bottom line, who is using what without toasting a lot of bulbs yet getting plenty light? -- PeteCresswell |
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DynoHubs: What light bulbs/LED emitters?
On Mar 14, 1:36*pm, "(PeteCresswell)" wrote:
What light bulbs/LED emitters are you powering with your Sturmey-Archer Dynohub? Front? * Back? I did the thing with the bridge rectifier to convert it's output to DC - figuring I'd drive some LED emitters to get max light. But I'm having problems with the voltage regulator part. I get the circuit tuned to put out, say, 1.5 volts with 6 volts coming in from a 4-battery test source and then when I put another battery in series, the output voltage rises to 2.something. Probably something dumb I'm doing in the regulator, and I expect to do it right eventually. But it got me to wondering how voltage-tolerant light bulbs and LEDs are. * My assumption going into this has been "not very", but I don't have much to base that on. Am I doing the voltage regulation piece in vain? *Do I really need regulation? * When I hang a voltmeter on the DC output it varies from 3 volts at a walking pace to about 20 volts on a downhill. So, bottom line, who is using what without toasting a lot of bulbs yet getting plenty light? -- PeteCresswell I was a liberal arts major, so I bought a Lumotec IQ Fly , crimped the spade connectors, and plugged it into my SON. Piece of cake. It's about as bright as my old 10W battery-powered Halogen NiteRider system. |
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DynoHubs: What light bulbs/LED emitters?
Per Hank:
I was a liberal arts major, so I bought a Lumotec IQ Fly , crimped the spade connectors, and plugged it into my SON. Piece of cake. Well, I majored in accounting.... and kept two checking accounts so I could use one one month and the other the other month - letting each run dry so I wouldn't have to deal with balancing a checkbook.... Finally graduated, but the fact that I did was no credit to the school... Having said all that.... Thanks for the terminology. Googling "Lumotec" led right to Peter White's page dedicated to generator lighting. http://www.peterwhitecycles.com/schmidt-headlights.asp -- PeteCresswell |
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DynoHubs: What light bulbs/LED emitters?
"(PeteCresswell)" wrote:
Per Hank: I was a liberal arts major, so I bought a Lumotec IQ Fly , crimped the spade connectors, and plugged it into my SON. Piece of cake. Having said all that.... Thanks for the terminology. Googling "Lumotec" led right to Peter White's page dedicated to generator lighting. http://www.peterwhitecycles.com/schmidt-headlights.asp Bike generators match very well to light emitting diodes. Here's a account of some experiments I did which you might find, um, illuminating. [ducking & running] http://www.zefox.net/~bob/bicycle/ 8-) bob prohaska |
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DynoHubs: What light bulbs/LED emitters?
On Mar 14, 8:05 pm, bob prohaska's usenet account
wrote: "(PeteCresswell)" wrote: Per Hank: I was a liberal arts major, so I bought a Lumotec IQ Fly , crimped the spade connectors, and plugged it into my SON. Piece of cake. Having said all that.... Thanks for the terminology. Googling "Lumotec" led right to Peter White's page dedicated to generator lighting. http://www.peterwhitecycles.com/schmidt-headlights.asp Bike generators match very well to light emitting diodes. The problem wiht LEDs is that the AC, non-regulated voltage out of the dynamo isn't well suited to driving LEDs without some extra electronics to convert the AC to DC and to keep the current and voltage constant. To achieve this at low cost and at high efficiency is not yet possible. This is why the few good dynamo LED lights are so expensive. A filament bulb requires only some over-voltage protection, doesn't care about AC or DC, and lends itself to more efficient optics. I wish that there would be some higher power dynamos, even at the expense of more drag and more weight. All that's needed is enough power to keep a 3W Cree LED, battery powered light, charged. A 4 cell Cree LED light that automatically switched between two sets of two cells (operating on one while charging the other from a dynamo) would be one solution that would be possible with a slightly higher power dynamo, and would give the best of both worlds. But you're talking about a $100 headlight by the time it's at the retail level in volume. |
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DynoHubs: What light bulbs/LED emitters?
Per Hank:
I was a liberal arts major, so I bought a Lumotec IQ Fly , crimped the spade connectors, and plugged it into my SON. Piece of cake. "(PeteCresswell)" wrote: Having said all that.... Thanks for the terminology. Googling "Lumotec" led right to Peter White's page dedicated to generator lighting. http://www.peterwhitecycles.com/schmidt-headlights.asp bob prohaska's usenet account wrote: Bike generators match very well to light emitting diodes. SMS wrote: The problem wiht LEDs is that the AC, non-regulated voltage out of the dynamo isn't well suited to driving LEDs without some extra electronics to convert the AC to DC and to keep the current and voltage constant. To achieve this at low cost and at high efficiency is not yet possible. This is why the few good dynamo LED lights are so expensive. A filament bulb requires only some over-voltage protection, doesn't care about AC or DC, and lends itself to more efficient optics. I wish that there would be some higher power dynamos, even at the expense of more drag and more weight. All that's needed is enough power to keep a 3W Cree LED, battery powered light, charged. A 4 cell Cree LED light that automatically switched between two sets of two cells (operating on one while charging the other from a dynamo) would be one solution that would be possible with a slightly higher power dynamo, and would give the best of both worlds. But you're talking about a $100 headlight by the time it's at the retail level in volume. I thought I might throw out my bikes and just sit down and cry because the world is imperfect. Instead, I just ride with normal dynamo lights. Installed once and never given a moment's thought since. -- Andrew Muzi www.yellowjersey.org Open every day since 1 April, 1971 |
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DynoHubs: What light bulbs/LED emitters?
In article ,
"(PeteCresswell)" wrote: Per Hank: I was a liberal arts major, so I bought a Lumotec IQ Fly , crimped the spade connectors, and plugged it into my SON. Piece of cake. Well, I majored in accounting.... and kept two checking accounts so I could use one one month and the other the other month - letting each run dry so I wouldn't have to deal with balancing a checkbook.... Finally graduated, but the fact that I did was no credit to the school... How did you know when an account went dry? -- Michael Press |
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DynoHubs: What light bulbs/LED emitters?
Per Michael Press:
How did you know when an account went dry? I didn't. But alternating checkbooks every month kept the amount of basic arithmetic necessary to balance to an absolute minimum. -- PeteCresswell |
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DynoHubs: What light bulbs/LED emitters?
On Mar 14, 8:36*pm, "(PeteCresswell)" wrote:
What light bulbs/LED emitters are you powering with your Sturmey-Archer Dynohub? Front? * Back? I did the thing with the bridge rectifier to convert it's output to DC - figuring I'd drive some LED emitters to get max light. But I'm having problems with the voltage regulator part. I get the circuit tuned to put out, say, 1.5 volts with 6 volts coming in from a 4-battery test source and then when I put another battery in series, the output voltage rises to 2.something. Probably something dumb I'm doing in the regulator, and I expect to do it right eventually. But it got me to wondering how voltage-tolerant light bulbs and LEDs are. * My assumption going into this has been "not very", but I don't have much to base that on. Am I doing the voltage regulation piece in vain? *Do I really need regulation? * When I hang a voltmeter on the DC output it varies from 3 volts at a walking pace to about 20 volts on a downhill. So, bottom line, who is using what without toasting a lot of bulbs yet getting plenty light? -- PeteCresswell In the tradition established in this thread: I was educated as an economist and psychologist and became an artist who occasionally publishes books on engineering as well. But I do know a little about electronics, in that I've worked for fifteen years or so with the kilovolt thermionic tube amplifiers I design and build. 1. I'm assuming your Sturmey-Archer dynohub is rated the same as every other dynohub, which is theoretically 6V 0.5A or 3W. It will in fact probably deliver more as it is built to German regulations that demand a high percentage of its total output at the equivalent of only 9mph. 2. The standard assignment of this power is 0.6W to the rear light and 2.4W to the front light; this assumes that the front light is halogen and the rear a red LED, so, if you don't lead any power to the rear, you can use a 3W front halogen. 3. Forget a dynopowered rear light of any kind. Even the best are dangerous to your health. The expensive BUMM ones are not watertight and the best of the rest, made by Basta (I have one they custom make for Gazelle but it is basically just an aesthetic variation of their best rear lamp) and by Spanninga (their Ultra; I have that one as well) are merely better waterproofed, not more illuminative. I keep them on my bikes simply because they came with the bikes. Even the best of the dynodriven rear lights are little glimmers that you can barely see across the street. None of the dyno-driven rear lights flash, because it is streng verboten to have flashing lights in Germany and The Netherlands, their prime markets. 4. Get a battery rear light. If you're rich, get a Dinotte rear light (ask Jay; he has one), if not a Cateye TL-LD1100, which is pricey enough. There is only one other taillight that is good enough for your life and that's the Trek Disco Inferno, which is no longer made. The Dinotte and the Cateye 1100 are *bright*, they cast very substantial light to the sides as well as the rear, and they flash. Those are the minimum requirements for good taillights, and they are the only ones who truly meet them. The Cateye 1100 is bright enough to be seen in bright sunlight; I use it as a daylight running lamp. It is supposed to last 200 hours on a set of 2 AA batteries; I don't know how long the batteries last in hours because I use rechargeables and swap them out every three or four months or so. 5. Now you're ready to consider your front light. Your dynohub will power halogen or LED lights that will give substantial light. 6. For a start, if you ride faster than about 10mph, you can fit a second halogen light and the dynobub will power both of them. A circuit is on the netsite of a guy who comes to RBT, name of Marten I think; possibly the firm is called M-Engineering. Peter White also has a circuit. You don't need the expensive SON lights; all they are are Bisy lights with switches, or BUMM lights with switches. You can buy the cheapest BUMM (round) halogen lights and make your own switchbox -- I made one with a three-position switch (off, one on, both on) in a plastic pill container and sealed it with superglue and fixed it to the handbars with a fat rubber band. 7. Or you might want to considering overvolting a single halogen lamp: you get far more light and you won't blow a Philips MR16 or MR11 longlife unit --anyway, what do you care if you reduce a 3000 mtbf lamp to 1500 hours of life if you get nearly twice as much light? The trick is that you must be able to get them in the 6V versions to work with your dynohub, and the 6V MR16 or MR11 are not easy to find, at least not where I live. But, once you have the right voltage lamp, they're incredibly easy to work with. I built a lamp with a common decorating type of MR16, 12V 20W, by simply soldering wires to the pins (you can buy plugs for the pins at any lamp store, electrical goods store or hardware store but they're more expensive than the lamps themselves which are supermarket items), glueing the lamp into a small Roma tomato puree can (it is exactly the right size) and glueing the wires into a hole in the back for strain relief; I overvolted it with the 14.4V battery from my drill, and fixed it to the handlebars with a clamp from a throwaway rear light I bought at the pound shop (US "dime store") specifically for this purpose. It made a stunning lamp, earning a lot of respect from drivers, and was capable of going for a ten mile ride on narrow country lanes with the drill battery. (Eventually I bought readymade lights because the package was cheaper than buying suitable rechargeable batteries, charger, case and so on.) 8. Or, in LEDs, you can fit as many low consumption LEDs as you can power. Each LED drops y volts, so the total must add up to what your dynohub produces or must be regulated. You might want to look into buckpucks to get the voltage right. Frankly, I wouldn't mess with LEDs unless I could get the latest and the best, together with some means of focusing the light correctly, and were also willing to sacrifice an existing set of lights with hefty, preferably cast ali, shells for cooling the LEDs. I looked into LEDs and decided that BUMM's Fly IQ (at the expensive end of their range, which is generally overpriced) would probably in the end cost less than messing around trying to make my own. 9. If you're cheap or poor, consider this. Plenty of RBT dickswingers will now weight in with how fabulous their BUMM Fly IQ is; I have one too and it is a good light. However. A couple of halogen 2.4W lamps -- because that is what I had at the time of the test; 2x 3W lights would do better still -- made as much light as the Fly at any speed over a crawl and could be better arranged because the two lamps had different spreads. The problem with a single light, any single light but especially those driven by dynohubs where the output is by definition limited, is that it is optimized for some particular patch, and there isn't enough power to light up everything. With two lights you can light the hole in front of the bike as well as the distance, and by angling the two lights carefully either have a smooth spread or distribute the available light to suit your preference. Example: I ride on narrow lanes with a high crown and a very sudden drop-off into the ditch -- I want to see both sides of the lane close to the bike, and on the downhill i want to see the curves well ahead; no one dynamo light can do both; in fact, even in big battery lights I use two separate lamps, each dedicated to one desirable purpose. 10. Lights are the last bicycle frontier. We hear a lot of talk from the technofreakies about how dynamo lights are now so much better than they were. But better isn't automatically good enough. The best dyno front light is still only nearly as good as a 10W MR11 battery light -- whereas I don't feel comfortable on any aspect of lighting (being seen, having my space respected, seeing) with anything less than about 25W divided between two lamps. YMMV, of course. 11. In summary: I recommend the Cateye TL-LD1100 battery rear light, and two cheap BUMM halogen lights driven off the dynamo at the front with a homemade switch, supplemented in case of regular commuting or any strenuous riding circumstances by a rechargeable battery front light set . 12. A simple test of whether lights are good enough is to go to the most dangerous road you ride on and check when drivers first see you and how they react. If more than one out of ten drivers don't see you and react appropriately until you sweep a light directly through his eyes, the lights are not good enough. The most dangerous road I ride at night is less than a minute from my house and is ideal for setting up an experiment because it is dark and has a hill to define the driver's first sight of the bicyclist. I found that with 10W of illumination on the bike, drivers 180 yards away did not slow after the crest, with 15W some slowed, with 25W almost all slowed, and the idiots would slow instantly if I swept that much light through their eyes at 100 yards. That's still less than a quarter the light output of a car putting two 55W beams on high to warn another driver. 13. Good strong lights are useful in daylight too. The flashing Cateye 1100 persuades a lot of people to slow behind me and to give me a wider berth than they did before I fitted that light. The key for a cyclist is to be seen and thought about. (When Jay has a bit more experience with his Electra, he will notice that his higher profile on the bigger -- and clearly expensive -- bike earns him more courtesy from drivers than was the case on his old folder.) 14. That applies to front lights as well. Example: Yesterday afternoon, while I was riding down a hill on another narrow road with parked cars on both sides, a driver coming from the front clearly intended, despite the fact that I had right of way, to bull his way past me by forcing me to stop and pull off. I switched on my front lights as a warning that I had seen him and had no intention of giving way, and he immediately had second thoughts, pulling out of my way between two parked cars to give me the road. A woman who was driving behind me also drove into the supermarket where I stopped. "You frightened that pushy son of a bitch ****less," she said, laughing aloud; it turned out he's her unloved neighbour and people have been talking about his foul manners on the hill to the estate where they live. 15. I'm planning on fitting a flashing high-power white or amber LED at the front, to operate whenever I'm on the bike including daylight, because the flashing Cateye red at the back has been so successful. I just haven't worked out yet if it will battery driven or if I should let the dynohub drive it. An attractive option would be a pair of good LED lights, with additional electronics to flash one, switched to come on in steady mode when required. 16. If you buy one of the German or Dutch rear lights I'm advising against, don't bother to get the self-switching one. I have three, and I take potluck about when any of them are in manual-on-off or auto-on- at-dusk mode because I cannot work out how to switch the modes. Furthermore, one of them at least does not meter light reliably and is confused by the common sodium type of street lights, and the motion sensor has been inoperative from new. (By contrast the light sensor on my Cyber Nexus groupset on my Trek Navigator works flawlessly to switch on my dynohub-driven front light at dusk and off again at dawn. Shimano used to make a light sensor/switch combo that reputedly worked well too with dynohubs, but it is a long time since anyone had stock of it.) HTH. Andre Jute http://members.lycos.co.uk/fiultra/ "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
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DynoHubs: What light bulbs/LED emitters?
On Mar 14, 9:05 pm, Andre Jute wrote:
3. Forget a dynopowered rear light of any kind. Even the best are dangerous to your health. The expensive BUMM ones are not watertight and the best of the rest, made by Basta (I have one they custom make for Gazelle but it is basically just an aesthetic variation of their best rear lamp) and by Spanninga (their Ultra; I have that one as well) are merely better waterproofed, not more illuminative. I keep them on my bikes simply because they came with the bikes. Even the best of the dynodriven rear lights are little glimmers that you can barely see across the street. None of the dyno-driven rear lights flash, because it is streng verboten to have flashing lights in Germany and The Netherlands, their prime markets. Good advice. I had some long discussions with Dutch manufacturers at the show about their products (and their lack of exporting to the U.S.), and especially about lighting. I was very suprised to see some new higher end Dutch commuter bikes with no dynamos at all, hub or rim. They told me that there is a trend even in the Netherlands toward battery powered lights at the mid-range for two reasons. First, the rim dynamos are too unreliable in terms of wiring and in terms of being damaged when the bicycles are parked, but the hub dynamos are too expensive except at the very high end. Second, the lights are only useful as "being seen" lamps at the relatively slow speeds on the cycle paths. 4. Get a battery rear light. If you're rich, get a Dinotte rear light (ask Jay; he has one), if not a Cateye TL-LD1100, which is pricey enough. There is only one other taillight that is good enough for your life and that's the Trek Disco Inferno, which is no longer made. The Dinotte and the Cateye 1100 are *bright*, they cast very substantial light to the sides as well as the rear, and they flash. Those are the minimum requirements for good taillights, and they are the only ones who truly meet them. The Cateye 1100 is bright enough to be seen in bright sunlight; I use it as a daylight running lamp. It is supposed to last 200 hours on a set of 2 AA batteries; I don't know how long the batteries last in hours because I use rechargeables and swap them out every three or four months or so. Other than folding bicycles, there were probably more new attempts at LED lights than any other product at the show, including several LED brake lights and turn signal lights, including some with wireless transmitters from a switch on the bars But in all the show, the best rear light remained the CatEye 1100. DiNotte was not at the show. There actually is a decent tail light from Blackburn (in terms of brightness and angle of view) but it suffers from using AAA batteries. 7. Or you might want to considering overvolting a single halogen lamp: you get far more light and you won't blow a Philips MR16 or MR11 longlife unit --anyway, what do you care if you reduce a 3000 mtbf lamp to 1500 hours of life if you get nearly twice as much light? The trick is that you must be able to get them in the 6V versions to work with your dynohub, and the 6V MR16 or MR11 are not easy to find, at least not where I live. Yeah, the poor man's HID system! Have you tried a 5W 6V MR16 on a 3W dynohub? "http://www.bulbtown.com/5W_6V_MR16_WITH_LENSE_GX5_3_BASE_p/43243.htm" 8. Or, in LEDs, you can fit as many low consumption LEDs as you can power. Each LED drops y volts, so the total must add up to what your dynohub produces or must be regulated. You might want to look into buckpucks to get the voltage right. Frankly, I wouldn't mess with LEDs unless I could get the latest and the best, together with some means of focusing the light correctly, and were also willing to sacrifice an existing set of lights with hefty, preferably cast ali, shells for cooling the LEDs. I looked into LEDs and decided that BUMM's Fly IQ (at the expensive end of their range, which is generally overpriced) would probably in the end cost less than messing around trying to make my own. I was surprised to see so few LED based dynamo lights at the show, because I incorrectly assumed that you could drive something like a 3W Cree LED from a dynamo hub. You can't. Most of the dynamo LED based lights were three lower wattage LEDs, and not focused or collimated all that well. Plus no manufacturer is apparantly willing to spend big bucks on the bins of the Cree LED that are the most efficient. The best LED headlamp appears to still be the SolidLight's 1203D. Interestingly, tthey don't mention the LED type anywhere, nor the wattage. 9. If you're cheap or poor, consider this. Plenty of RBT dickswingers will now weight in with how fabulous their BUMM Fly IQ is; I have one too and it is a good light. However. A couple of halogen 2.4W lamps -- because that is what I had at the time of the test; 2x 3W lights would do better still -- made as much light as the Fly at any speed over a crawl and could be better arranged because the two lamps had different spreads. There is a mistaken belief by many that an LED based light is necessarily more efficient than a filament based lamp. This is untrue for higher power lights. The measures taken to dissipate the heat from a high power LED lamp are quite incredible. Plus an LED llamp is much harder to lens properly. There are advantages, such as the longer life of the LED compared to the filament based bulb, especially in a harsh environment. You keep hearing how LEDs will soon catch up with HID in terms of efficiency, and this may happen but it's not going to be cheap. The LED manufacturers already charge a big premium for the their most efficient product bins, and you see Cree based lights specifying which bin the LEDs come from. 10. Lights are the last bicycle frontier. We hear a lot of talk from the technofreakies about how dynamo lights are now so much better than they were. But better isn't automatically good enough. The best dyno front light is still only nearly as good as a 10W MR11 battery light -- whereas I don't feel comfortable on any aspect of lighting (being seen, having my space respected, seeing) with anything less than about 25W divided between two lamps. YMMV, of course. Personally I find MR11 based lamps a waste, because the larger reflector of the MR16 is much more efficient. In fact the sealed beam 12 volt lamps are becoming one of my favorite halogen lamps because of the large reflector, light weight, and the lack of a need to build any funky enclosure. 11. In summary: I recommend the Cateye TL-LD1100 battery rear light, and two cheap BUMM halogen lights driven off the dynamo at the front with a homemade switch, supplemented in case of regular commuting or any strenuous riding circumstances by a rechargeable battery front light set . Good advice. I'm finding that for many short, slow rides to the store that the dynamo lights are sufficient. It's for commuting, especially at relatively high speed, that the higher power lights are necessary for optimal safety. 13. Good strong lights are useful in daylight too. The flashing Cateye 1100 persuades a lot of people to slow behind me and to give me a wider berth than they did before I fitted that light. Try a Flash Flag. See "http://www.flashback.ca/bicycle.html". You can probably make something similar. I use these on most of our fleet of bikes, but I'm working on something better. I don't like the lack of a good breakaway mechanism. Some sort of replaceable, cheap mechanism is needed. I was hoping to see something similar to the Flash Flag at the bike show, but there was nothing. |
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