I would like to build my own LED bicycle headlight ... - Page 1
Forum section: electronics / general

author: DiTBho
author_rank: Super Contributor
timestamp: September 02, 2024, 12:21:00 pm
content: soIt's Septermber, Summer is ending, September brings with it far fewer sunny days, more dark days.I am fully back to work and It's been raining cats and dogs for three days.Autumn and Winter days will have less light in the late afternoon since I don't have time in the morning, but I can only train after work, so after 6:00 pm, I will almost certainly return home with little light.After the bad accident I talked abouthere, which was caused also by not having a bright enough headlight on the bike, I would say that it is time to get a suitable one!I found some light products that seem reliable and good for cycling on dark roadsGarmin Varia UT800, seehereTopeak Whitelite HP500, seehereVis Pro1000 Trail, seehere...However they are very costly and limited by an internal battery.After the incident, I found my wheel-set is gone, too damaged to be repaired, it must be replaced.So, I would like to use a front dynamo hub for the new front wheel, and take advantage of its dynamo hub.I have a 3 Watt one here, and it would be nice to avoid being limited to 1-2 hours of LED lighting due to an internal lipo battery, which you can not even replace.-So, I would like to build my own LED bicycle headlight, and I would like to build it as a smart lighting device, with an ambient light sensor and an accelerometer that automatically modulate the PWM.LikeGarmindid with theVaria UT800, but powered by the dynamo, and with full control of its firmware to avoid being frustrated as you can read in some product reviews, because users want to use the light in one way, and theGarmin' firmwaredoes not allow them to.I would also like to add a button on the ergopower, to activate the boost mode, on the sections of road that are particularly worrying. In addition to the dynamo, I would also like to use super capacitors (from the material of a fake water bottle) to give extra current to the LED in the boost mode.There are no problems for the electronic/firmware part, but I am a bit stuck on the optical part where to find the lens.* * *Which lens to get, etc. Do you know of anything I can use?

author: Njk
author_rank: Frequent Contributor
timestamp: September 02, 2024, 12:37:49 pm
content: It's difficult. Sure you can come up with all your design files and find an affordable CNC machining service in your area. But custom optics manufacturing service can be much more expensive, I guess. While it's not an option for a bicycle headlight to use a COTS architecture lighting lenses

author: dave j
author_rank: Regular Contributor
timestamp: September 02, 2024, 12:45:27 pm
content: For the optics/housing, is repurposing an old bike light designed for incandescent bulbs worth looking at? There's got to be loads of old ones knocking around that people have replaced with LED lights and don't want any more.

author: Njk
author_rank: Frequent Contributor
timestamp: September 02, 2024, 12:58:18 pm
content: Quote from: dave j on September 02, 2024, 12:45:27 pmOne problem is that for an incandescent bulb, cooling is less critical than that for a LED. The old housings are not designed with that in mind. Very substantial changes will be required.

author: themadhippy
author_rank: Super Contributor
timestamp: September 02, 2024, 01:03:38 pm
content: Nip down the local motorbike scrappy and have a mooch

author: dave j
author_rank: Regular Contributor
timestamp: September 02, 2024, 02:19:47 pm
content: Quote from: Njk on September 02, 2024, 12:58:18 pmEven if the housing itself isn't suitable, it could be a cheap way of getting a suitable lens and reflector.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 02, 2024, 03:34:50 pm
content: Quote from: DiTBho on September 02, 2024, 12:21:00 pmFor the love of dog and all that is furry,pleasedon't let it visibly pulse or flicker. (Anything above 100Hz is fine, although I personally prefer much higher.)I'm one of those people who cannot tolerate light flicker. When I go for a walk in the late evening when a bit tired already, those low-Hz bright pulsing bike lights make me nauseous. In actually photosensitive people, they can trigger an epileptic seizure. I understand it prolongs battery life by 2×-5×, but the problems they cause to myself and others makes me believe they should be made illegal.

author: nctnico
author_rank: Super Contributor
timestamp: September 02, 2024, 03:48:23 pm
content: Quote from: Nominal Animal on September 02, 2024, 03:34:50 pmNot only that. When driving a car you can't follow where a blinking light is coming from or going to. So it actually doesn't help to be safer as you can't determine whether the bike is on a colission trajectory or not!Back to the design: I'd start out with high efficiency LEDs and put those into a suitable reflector housing. For riding off-road it could make sense to have two headlights. One with a narrow beam and one with a wide beam. But I think there are readily made headlights available with are good. I have a bike from a brand called Batavus (well known Dutch A-brand) and the LED headlamp that came with it is fine for riding when it is pitch black dark. Or put differently, the trick is to avoid the crap they mount on cheap bycicles.I would avoid using batteries of any kind. I specifically modified my bike to also power the rear light from the dynamo as changing the batteries is cumbersome and you never know when they cut out. Driving without proper lights on a bycicle in the dark is dangerous. People won't see you.

author: Njk
author_rank: Frequent Contributor
timestamp: September 02, 2024, 03:52:52 pm
content: Quote from: dave j on September 02, 2024, 02:19:47 pmPerhaps. But that lenses are typically of glass. What you'll do when it's accidentally broken? It can be a problem to find exactly that lenses for replacement. Moreover, you can't make as many products as you want. Generally, it's better to avoid a non-scalable solution.And from the engineering perspective, you'll be forced to use a classic optical scheme, where the light source is located at the focal point of the reflector. It's the only practical scheme for a bike light with an incandescence lamp. While with LEDs, it's possible to use a more advanced schemes, where the light from the source is rotated by the reflector (what Busch+Muller and Outbound Lighting does). That allows for better cooling and beam forming. So with old parts, all the design efforts will result in outdated product, in best case

author: DiTBho
author_rank: Super Contributor
timestamp: September 02, 2024, 04:21:10 pm
content: Quote from: Nominal Animal on September 02, 2024, 03:34:50 pmYup, usually, it's 1kHz.The control unit that does the dimming on the LED panels in the helicopter hold is even 10Khz.

author: DiTBho
author_rank: Super Contributor
timestamp: September 02, 2024, 04:41:32 pm
content: Quote from: nctnico on September 02, 2024, 03:48:23 pmThe night of the accident, I was using a LED headlight made by XOSSXOSS, XL-400, seehereIt costs between 20 and 30 euros, it's what Amazon suggests the most. The brand XOSS is not that bad, but I have to say that specific LED headlight didn't give enough light for the road conditions I was on, certainly not the 400 lumens declared, in addition to the fact that the battery lasts really little, again less then how declared.In my case, the bicycle is an old 90s steel road frame.For the front dynamo hub, I have two alternativesShimano Nexus, Shimano DH-C3000-family, 3W/6V, 36H, quick release mechanismSturney Archer X-FDD, 3W/6V, 36H, It also integrates a drum brake, has bolt tighteningFor this specific bicycle, which is my training one, I already have the Shimano hub at home, and I would leave aside the Sturney Archer alternative for two reasonsIt weighs 1.2Kg, and I don't need a drum-brake on that bike. The RIM-brake is fine.I will need it on a bicycle I will use in Norway, but that's another story, and another bicycleNot having the quick release mechanism is a real problem to take the wheels on a plane because you can't put them in the classic "bicycle bag" since the hubs have a protruding axles on both sidesYou need specific bags, made to measure, nobody produces them.I have already talked about it in another topic, it's a problem that I'm solving, but that I haven't solved yet.* * *In any case, both hubs offer 3W/6V, which is not much in terms of current.

author: nali
author_rank: Frequent Contributor
timestamp: September 02, 2024, 04:50:08 pm
content: If those hub gennys are like my Schmidt, they'll provide more than 3W over 20kph; in essence they act as a speed-dependent voltage source with a maximum current of around 500mA. So as a little side project you could build a MPPT regulator and switch in extra LEDs as an automatic "high beam".It's one of my "never got round to" projects

author: langwadt
author_rank: Super Contributor
timestamp: September 02, 2024, 04:51:07 pm
content: start with a cheap LED torch ?

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: September 02, 2024, 05:14:06 pm
content: You can buy aluminum-backed LED boards here:https://www.ledsupply.com/leds/cree-xlamp-xhp35-high-densityThere are many models to choose from, with different LEDs, color temperatures, etc. Once you've settled on an LED type and board, you can pick from the optics available on the same site. When I built a bike light, I chose an elliptical spot lens so that the beam is confined vertically to avoid dazzling oncoming cars, while giving a decent horizontal spread.https://www.ledsupply.com/led-optics/10510-carclo-lens-3-up-elliptical-spot-led-opticThey have many other lens vendors available, suitable for LED boards with different numbers and types of emitters. The single-emitter lenses also need a plastic holder to keep it aligned with the board. You can also find housings and compact LED drivers on the same site:https://www.ledsupply.com/led-heatsinks/dynamic-led-heatsink-housinghttps://www.ledsupply.com/luxdrive-constant-current-led-driversMouser seems to carry the lenses under "LED lighting optics", and are cheaper, but the parametric search doesn't have anything useful to search on.

author: mendip_discovery
author_rank: Super Contributor
timestamp: September 02, 2024, 06:07:43 pm
content: Just buy one of these,https://www.aliexpress.com/item/1005006723526188.htmlTBH I know it's heavy etc but can't you fit an LED headlight unit from a motorcycle, use a 12V battery pack from a UPS. At least you would have dip and main.Other options include looking at what they offer for the off road motorcycles, Polisport makes some headlight kits and if you feel rich then look up Touratech.If I can ride a 1961 Matchless G3LS at 6V at night while at times going more than 60mph it should be enough light or you need to slow down.

author: IanB
author_rank: Super Contributor
timestamp: September 02, 2024, 06:23:06 pm
content: Rather than use a purpose designed bike light, I would be inclined to consider a regular torch (flashlight) with a suitable mounting bracket. These are regularly designed with removable batteries (typically 18650 lithium ion or some such), so you are not limited to duration of a built-in battery. You could easily carry one or two spares with you. The optics of such a torch will be way better than anything you can concoct yourself.If you are really keen, you could cannibalize such a light by replacing the internal battery with the external supply from the dynamo, or arrange a charging circuit to keep the torch battery continuously topped up. But this seems like a lot of work, and I don't know if it would be worth it.

author: DiTBho
author_rank: Super Contributor
timestamp: September 02, 2024, 06:24:31 pm
content: Quote from: mendip_discovery on September 02, 2024, 06:07:43 pmWell, I'm not one to spend money on aerodynamic accessories ...such as { aero helmet, aero water bottle, aero fork, aero seat tube, aero wheels ... }but ... I do trips of 120km, and that big thing at 30-35km/h average ...... certainly creates so much air resistance that it gives me a sore neck

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 02, 2024, 06:27:12 pm
content: If you mostly drive at night with minimal extra weight, ignore this post.Edit: IanB basically said this better above.How about designing the power side so that you have a removable rechargeable battery pack, and lets you choose between charging it from your dynamo, isolating it and using only the dynamo for the light, or using only the battery pack for the light?You could even make different capacity packs for different types of trips. When going on a holiday trip without a support car, you'll have many kg of cargo anyway, so having an additional battery pack is likely not a big deal.Add optional 5V output regulation, and in an emergency, you could charge your phone with the dynamo enough to make a quick call.

author: radar_macgyver
author_rank: Frequent Contributor
timestamp: September 02, 2024, 06:30:27 pm
content: Battery pack: you can make a pack from 18650s, shrink-wrap them with poly film and zip-tie to aclip-on bottle holderto make them easily removable for charging/theft prevention. Waterproof barrel plugsare available(meant for dive lights, apparently). Alternately, use an old bike water bottle (I used one that got leaky), this makes the batteries waterproof, and you can use a standard bottle holder. This does make the wires a bit longer though.

author: DiTBho
author_rank: Super Contributor
timestamp: September 02, 2024, 06:33:08 pm
content: Quote from: IanB on September 02, 2024, 06:23:06 pmI listed 3 products in my previous post.They are all no less than 100 euro.The Garmin Varia UT800 costs 130 euro.Would you cannibalize it?They usually have waterproof protections, and designed to avoid you to be able to replace the battery.I do not even how to open them without breaking them.TheXOSS XL-400has a lens and rear cap glued with resin: how do I open it?It was damaged in the impact, the lens is horribly scratched and there are quite deep dents, so much so that they have damaged something, because it no longer turns on.For me it is to be thrown away, and I am tempted to use a mini Dremel to cut along the cap, which unfortunately they have glued, so I can open it.

author: IanB
author_rank: Super Contributor
timestamp: September 02, 2024, 07:05:55 pm
content: Quote from: DiTBho on September 02, 2024, 06:33:08 pmYou listed three specialized bike lights.My suggestion was to think outside the box and not look at bike lights, but look at regular "tactical" flashlights combined with a mounting bracket.A few years back, everything had removeable batteries, either AA or 18650. Now it seems times have changed, and most lights have a built-in battery and USB C charging. You need a time machineHowever, apart from the lights you listed, brands like Olight and Fenix have bike light offerings. If they have a USB C charging port, you could connect the dynamo to a USB C charger, and plug that into the light, so it would charge as you ride along. You would have to check that it can be charged while in use.If you did this, you would not have to cannibalize anything.But my suggestion was to possibly modify a $30 light, not a $100 light. There are inexpensive lights that take 4 AA cells, nominal 6 V, which would be compatible with a dynamo output.

author: themadhippy
author_rank: Super Contributor
timestamp: September 02, 2024, 07:17:10 pm
content: Quotenot road legal in the uk,all bike lights are supposed to be fixed to the bike

author: IanB
author_rank: Super Contributor
timestamp: September 02, 2024, 07:18:43 pm
content: For example, this inexpensive light has a nice adjustable beam pattern from wide to narrow, it is bright, and it runs from 4 AAA cells (nominal 6 V). It apparently has a regulation circuit inside to control the brightness of the light, so any approximately 6 V DC supply should work.https://www.harborfreight.com/590-lumen-tactical-led-flashlight-black-59362.htmMaybe you can find something similar in the UK, or online?To add an external power supply, you could drill a hole in the side, run a cable through, and seal it up with silicone. Or even fit a waterproof power jack and wire it up internally.

author: DiTBho
author_rank: Super Contributor
timestamp: September 02, 2024, 07:38:29 pm
content: @Nominal AnimalIn the Summer, when I don't have to work, I can wake up early in the morning, take my bike at 5 in the morning and go for a ride.On the day of the accident, I was late on my way back, otherwise I would have arrived home with the streets still lit.The problem is in Autumn and Winter, when it gets dark earlier than in the Summer, and, having to work.I can only train after work, that is, after 6 pm, returning home in the dark, 2 hours later.

author: nali
author_rank: Frequent Contributor
timestamp: September 02, 2024, 07:49:35 pm
content: Quote from: IanB on September 02, 2024, 07:05:55 pmBike lights (well mine, anyway) have a trapeziodal light pattern, so they have a more consistent illumination pattern when angled downwards. Plus side lobes to illuminate the kerb or verge.Edit: Added image (from sales literature, not mine)

author: IanB
author_rank: Super Contributor
timestamp: September 02, 2024, 08:00:22 pm
content: Quote from: nali on September 02, 2024, 07:49:35 pmI guessed that might be the case.In the old days before LEDs, bike lights were dim and couldn't light up the road at all. Now, they could be almost as bright as car headlights. So it makes sense to have a beam pattern to avoid dazzling oncoming vehicles, as well as putting more of the light where it's wanted.But a small LED light with the sole purpose of being seen might not need much in the way of a beam pattern, perhaps?

author: mendip_discovery
author_rank: Super Contributor
timestamp: September 02, 2024, 08:33:28 pm
content: Quote from: themadhippy on September 02, 2024, 07:17:10 pmWhat does legal stuff have to do with cycling? Its not like they can be told off or anything. Even these electric motorcycles are free for be used by everyone, the police are too busy to do anything about it.

author: deadlylover
author_rank: Frequent Contributor
timestamp: September 03, 2024, 02:32:54 am
content: Yeah I'd figure out a flashlight mount and just change the lens.Buy something like aConvoy S21Eand get anelliptical lens (they call it striped).I like the Nichia 519A emitters, relatively neutral (though sometimes a bit above the BBL) with good CRI. Make sure you get the version with the Anduril driver, you'll be able to flash the version to Anduril 2, though I'mpretty sure Anduril 1has a bike flasher strobe as well.

author: Njk
author_rank: Frequent Contributor
timestamp: September 04, 2024, 04:24:35 am
content: The lighting requirements depends on the untended use. A trail ride is a dumb case. To flood the front area with more light. Just attach any flashlight powerful enough to the bike and you're all set. But a road ride is a more complex case because generally, a well collimated beam of several degree of divergence angle is required (you can always add some diffusion if necessary, it's not a problem). According to the optics science (etendue etc.), the larger the aperture size (the lenses diameter), the more collimated beam can be produced with given light source aperture and target efficiency loss. That does not mean that such a beam can't be produced with a small lenses, I've old Inova X1 spotlight that has a lenses of the AA battery diameter and produces a beam like that of laser pointer. But that's with high losses. If you remember, old bicycle headlights were quite big, of more than 50 mm housing outer diameter. I presume that's because incandescence bulbs produce not so much light and it was essential to minimize the losses. But actually, a LED has less brightness density, it uses larger light emitting surface (source aperture) to produce higher perceived brightness. It's typical for a power LED to have 1x1 mm emitting surface area, which is much larger than that for the incandescence. That means that a LED requires even greater lenses aperture (at least 40 mm effective aperture diameter for automotive headlight applications AFAIR). While most of the modern bicycle headlights are much smaller. Perhaps that's because now it's not necessary to be an optics engineer to design and sell a cute LED lighting device packed with Wi-Fi, BT and Ant features.One of my former colleagues was a railway automation engineer by education. According to him, it usually does not make sense to build a hermetically sealed housing for an outdoor equipment. It's not a diving equipment, after all. It adds cost with little to no benefits. Even with no leaks, the water will appear from the internal air as the temperature change. Soon, the vapors will reach the electronic components (no matter of conformal coating) and start the corrosion. It's possible to fill the internal volume with a pressurized inert gas, but that adds even more cost and maintenance burden. A better approach is to build a splash-proof housing and fill the inside with a sticky viscous substance, like grease, fat, etc. That makes a visual inspection during the maintenance a nightmare, but it really works and it's cheap. For a bicycle accessory device, the water-tightness is a nonsense. It's not technically feasible for a cheap and lightweight device. Instead, it shall be made such that user can easy take it apart for periodic drying, cleaning and possible parts replacement. It's a very important requirement for bicycle headlight, but currently I'm not aware of such a headlights too.The images below are for B&M IQ-XS E headlight. The IQ2-Tec optics that uses additional small prism. It's a well known model so many reviews can be found on the internet (e.g.https://fahrradbeleuchtung-info.de/testbericht-busch-mueller-iq-xs-e) and some the images are not mine. It's not super easy to take it apart but that's perfectly doable with no damage using a plastic card of the right thickness. I'd used my old driving license for that. It's a E-bike version so there are no huge caps for energy storage inside. It's of recent batch with re-designed reflector for horizontally wider beam.It's a lighting device so optics is king while electronics is of secondary importance. But here is an electronics forum so some words about. There is no MCU (isn't it very good?) since the automatic switching between the night and day modes is done in a simple HW way by the mean of phototransistor. The BOM:IC1: TI LM3404MA (1.0 A CC buck regulator for high power LEDs)IC2: TI LM2731XMF (1.6 MHz boost converter with 22V internal FET switch)T1, T5: OnSemi FDC5614P (P-channel logic level MOSFET, 60V 3A, 105mΩ)T2: Diodes DMN2058U (20V N-channel enhancement mode MOSFET)T3: Diodes DMG3420QU (20V N-channel enhancement mode MOSFET)T4: Diodes BSS138W (50V 200mA N-channel enhancement mode MOSFET)T20: Osram SFH 320 FA (IR NPN phototransistor, 980nm, 120°), likelyLED1: Osram KW HHL532.TK (3.2W, 395 lm)

author: Zero999
author_rank: Super Contributor
timestamp: September 04, 2024, 09:47:51 am
content: Quote from: nctnico on September 02, 2024, 03:48:23 pmThat's true, but flashing lights are better at attracting attention. This is why emergency vehicles and roadwork sites use flashing, rather than static lights.I normally use flashing lights when it's not dark, but very cloudy or twilight, because it catches the attention of other road uses and drivers can still track me because I wear a fluorescent vest. At night, I use both a flashing and static light, which is the best of both worlds. Flash frequency is important. It mustn't be too high because it's annoying and can trigger photosensitive epilepsy.Perhaps the original poster could use a light which is static, but pulsed at a higher intensity every second, or one static light and a flashing one.

author: EC8010
author_rank: Frequent Contributor
timestamp: September 04, 2024, 11:02:20 am
content: Quote from: mendip_discovery on September 02, 2024, 08:33:28 pmSadly, it matters when you have an accident. I've been knocked off my bike twice by the Police (and my wife reminds me that I was nearly run over on a foot path by a Police car). First time, policeman suddenly opened his car door in front of me which I wrecked with my knee before sailing over the top to land in the road. Second time, going off-duty special constable turned right across my path forcing me to brake so hard that I stood the bike on its nose and saw his rear wing pass by about 6" from my nose. It wasn't a stable position and I broke my arm when I landed. In both cases, driver tried to find fault with me (cyclist). Nevertheless, despite not having a witness, I fought the cases and obtained compensation. Have an accident at night and even if your light is perfectly good and you are in the right it will be harder to fight your case.

author: thm_w
author_rank: Super Contributor
timestamp: September 04, 2024, 09:54:25 pm
content: Having built ~10 bike lights, its not really worth it for a front light, unless you need a very specific feature. For accent lighting or helmet lights it can be worth making your own.Buy a magicshine EVO1700 (cbl1600), or similar, and then use the dyno output to charge it over USB:https://www.aliexpress.us/item/3256806555421828.html- 1700lm with a flat cutoff- 4000mAh battery- wireless remote- downside: not good for daytime use, better at night

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 05, 2024, 05:20:42 pm
content: Quote from: Zero999 on September 04, 2024, 09:47:51 amYes; but the flashing one doesn't need to be the main nor the brightest one. That's the objectionable configuration.Things like reflectors in both your shoes and your head can make you more recognizable, too, because of the movement pattern; just a simple blinking light is not enough for someidiotshumans to recognize there is something to consider there. Some just don't associate a blinking light with a bicyclist or a pedestrian or a pet on a leash, just think of it as a blinky light.I've found the clip-on red LEDs some pet walkers use at night very intuitive; and when there are a couple in the leash also, very easy to detect from quite far off, and thus predict the movements of. Just something to consider, mind you.Quote from: Zero999 on September 04, 2024, 09:47:51 amIf it matters any, I don't ever recall getting nausea (I don't get seizures, so not "true" photosensitivity) from a static front light and flashing notification lights (like say the common red one in the rear reflector, or a weaker flashing white one in your hat); I've only gotten it from the main front white flashing one.(Blue lights are not legal here, they're reserved for emergency vehicles only. Some bike lights are too cold/blue.)

author: DiTBho
author_rank: Super Contributor
timestamp: September 08, 2024, 09:50:21 am
content: Quote from: Nominal Animal on September 05, 2024, 05:20:42 pmuh, I spent yesterday afternoon checking the pedals. I had bought them only five days before the accident and wanted to check their mechanical condition before thinking about removing the scratches and polishing them.Luckily I didn't mount the Campagnolo Super Light pedals made in the late 80s with titanium axle (~150..200 euro NOS) but the cheap japanese MKS Sylvan track (35 euro + 14 euro for a couple of ceramic ball-cages) still in production, because unfortunately, once inspected, I discovered that the axle of the right pedal is bent and the ball cage is damaged, or rather a pair of ceramic balls, a much harder material than aluminum, has deformed the internal raceway creating a hollow, something that now compromises the smoothness of the balls, you hear a terrible creaking, and that's the sound of what is not worth repairing them and you'd better thrown away.I don't like "road pedals", I prefer "track pedals", which are 1 inch shorter and usually without the extra protection for dust cups.Track pedals usually don't have any reflectors installed and don't even have a hole to screw them in.For strange reasons all orders in my area of that model of pedals have a two month waiting period, but Good News!!! I found exactly the same pedals second hand in perfect condition and with an interesting modification: two M4 holes to install reflectors!I was thinking of drilling them myself, but hey? Good Job already done

author: Zero999
author_rank: Super Contributor
timestamp: September 08, 2024, 10:51:08 am
content: Quote from: Nominal Animal on September 05, 2024, 05:20:42 pmI nearly had an accident because some idiot had blue lights on their bike, on a cycle track which has blue illuminated studs, near the edge. It was dark and foggy and I thought the cyclist was the edge of the cycle track, until I got close and realised.Quote from: DiTBho on September 08, 2024, 09:50:21 amAlternatively you could stick reflectors on your shoes.Or how about designing some lights to sick on your shoes? A flexible PCB, high brightness amber LEDs (phosphor converted might be the best), a lithium ion cell and charging IC, are all that's required. You could cover it in a few layers of conformal coating to keep the moisture out.

author: Nominal Animal
author_rank: Super Contributor
timestamp: September 08, 2024, 03:24:03 pm
content: I'd say reflectors on shoes or pedals or calves suffice. Also, one or two reflectors in the spokes of each wheel makes one very distinctive when seen from the side; the dual motion is key.There are huge differences between reflectors, though. Some of the reflective tape I've seen is amazingly reflective/effective. I've seen many quite poor red ones (as used at the back) and amber ones (spokes) and even white ones (for pedestrians), that look like they should work but when tested in dark do not reflect at all well, so pay attention to what you use and check before trusting.Having the bike helmet reflect light is particularly useful, because even the oblivious ones associate such reflections with a human head. (I don't mean it should be completely reflective, just that any part on it reflecting light, combined with static or moving reflections on the bike, is almost always associated with a bicyclist.)Using the quirks of human perception to convey theideaof a bicyclist being there is what I'm driving at. Pardon the pun.

author: themadhippy
author_rank: Super Contributor
timestamp: September 08, 2024, 04:48:29 pm
content: QuoteSo last century, strip of individually addressable rgb leds on a spoke is were its at,the rotation of the wheel enables some pretty good animations and patterns

author: Someone
author_rank: Super Contributor
timestamp: September 08, 2024, 09:18:05 pm
content: Quote from: Nominal Animal on September 08, 2024, 03:24:03 pmCheap too, quick way to add night time visibility to any hard surface.

author: cosmicray
author_rank: Frequent Contributor
timestamp: November 19, 2024, 11:55:58 pm
content: OP, I have something that may interest you. It is a work in progress, and has been sitting waiting for TLC for a few years, but I'm making progress again. A single 100mm x 100mm PCB, with two LM317L regulators, 100x 2835 white LEDs, and about 56 SMD resistors.Powered by a Ryobi 18V 2 aHr pack, using an adapter I found on eBay to pick off the voltage. Measured current is ~109 mA. When I did an endurance test, I got ~19 hours of full brightness, then 2 hours of fading brightness which is when I called it quits. Pack recharged in less than an hour. I'm now working on a box housing for it, so that I can mount a pair of these on my recumbent trike, and light up the bike path before sunrise.