flashing multiple Luxeon? (red Luxeon rear bike blinker)

[greenLED]

OK, that's it!!

I'm sick and tired of the dismal quality of the red, 5mm LED, tail light blinkers available for bikes. There must be something brighter and of better quality out there.

Since usually my wild dreams require custom solutions (which have slim chances of being completed by me, but I do trust somebody else will take off runing with the idea), I'm posting here.

This is my ideal bike taillight:

• 3-5 red Luxes: 3 pointing directly back and 2 pointing sideways (or a at 45-60º from the other 3), or 1 pointing back and 2 sideways.
• 2 modes: on/blinking/"chase" mode - none of those silly 7 mode lights that do nothing but annoy me when I have to cycle through all of them 3 times to turn the light off...
• waterproof to 1m
• appropriate heatsinking (which may require fins and/or a metal casing), since we're talking Luxeons here
• simple battery options - since I'm a geek, 123's will do, thankyouverymuch, but I don't mind AA's (no AAA's or external)
• small
• with a secure attachment system

Short of all that, does anybody know of a circuit that will drive 3-5 red Luxeons and provide flashing functionality?

[jch79]

+1 - To everything you wrote, although AAA's would be fine with me, provided they could be NiMH.

Other than that, my rear LED light has taken a huge beating the past year or so, and has started to fall apart, literally.

My "tweaks" to your request would be: On - Blinking - Alternating... the reason for this is that blinking lights attract attention, however a light that alternates really does it in some environments. My current rear light has 7x5mm vertically stacked LED's, and flows from top to bottom, and then back up, rather quickly... I think some drivers are used to seeing blinking lights, so this one is a real attention-getter.

Anyways, I'd sacrafice this if the light was actually powerful, sturdy, waterproof, and CPF-made!!!

Good idea on thread placement too... if we could get enough people interested in such a beast, maybe one of our many capable CPF machiners would give it a whirl!?!

john

[greenLED]

Other than that, my rear LED light has taken a huge beating the past year or so, and has started to fall apart, literally.

My "tweaks" to your request would be: On - Blinking - Alternating...

Totally agree on your tweak, jch79. I actually don't use the blinking mode on my bike's tail light; I use the "pursuit" mode where the LED's "chase" themselves rapidly. I figured it's more annoying than the regular blinking pattern...


I had been using some "cheap" tail lights I got from Nashbar a while back. They're the same construction as the Y/G ones Sigman is selling, but in red. I like them a lot (fairly sturdy, use AA, decent water seal -once I put some silicone on the gasket). The only problem is that the lens is brittle and it can crack just from opening the case (you gotta pry it open with a coin), or if you drop the blinker on a sidewalk (I'm a klutz, what else can I say?), or my "testing department" (that'd be the little one in the house) subjects them to a regular torture test... yeah, they do kinda fall apart.

Anyway, I'm down to my last blinkie (amber, not even red), so I ordered a new red one from Nashbar, but the quality of their new batch is... well The case doesn't seal properly, it's soft plastic, the attachment system is a joke...


Most of the other "cheap" ($10-20 range) blinkers I've seen share some (if not all) of the qualities of the POS I just got. If I add up all the money I've spent in cheap blinkies I probably would've saved myself some money by buying/building a $75 light to begin with. At the same time I'm sitting here thinking "there's gotta be something better without having to pay $130 (plus battery and charger) for a Dinotte tail light"...

So, that's what's behind this rant/post of mine. Thanks for letting me vent. Hopefully we can brainstorm and get something decent (both quality and price-wise) built.



In the spirit of full disclosure (for those of us/you not interested in DYI stuff), here's a decent hread discussing LED bike tail lights.

[damon]

just a suggestion
maybe ur can attach the fenix P1D CE with some red filter in strobe mode to the bike that might work

[Bandgap]

Kingbrite do some 10cd red-orange 5mm leds that are both cheaper per lumen and (as far as I can tell) use less power per lumen that red Luxeons.

And they don't need a secondary optic. You just drill 5mm holes pointing the way you want the light to go and epoxy them in.

How long are you expecting 5 Luxeons to run from AAA cells? - sounds like you might have to run them at less than full power.

I have a bicycle tail light made using 6 10cd 620nm 5mm leds and that is a pretty bright tail light (they do all point straight back).

Good luck

Steve

[Steve K]

Taillights!! My favorite subject, after headlights. :-)

5 red Luxeons does sound like a wonderful thing, except for how to power them. If you could power it from the headlight battery, then it might be reasonable. If it is powered from AA's, then it would need frequent recharging, which I would find annoying.

Maybe a single red Lux with an oval beam pattern optic? and 5 or 10mm red leds facing to the sides?

Well, in any case, either approach is possible.

Packaging is a big challenge, in my experience. I usually use an aluminum backplate, which also serves as the mounting bracket and as a heatsink if needed. I make the sides and top from plexiglass. The sides get epoxied together, and to the backplate. The top is RTV'ed on, so as to permit changing batteries. This is acceptable if you only change batteries once a year, but not if they get removed frequently.

If you use rechargables, then you might want to have a bulkhead connector to allow a charger to be plugged in. Or... find a commercial box with a screw-on top that uses a good o-ring or gasket to seal it. Catalogs like Digi-key or Newark sell a wide variety of boxes of this type.

In terms of circuitry.... this would be a good project for a small processor. For myself, I've considered using a 555 with a switchable frequency. Using a 20% duty cycle, at low frequency the light would look like a strobe. Selecting the higher frequency would result in a steady red light with a lower perceived intensity. For the best water resistance, I'd suggest rigging up a reed switch to control power. Or a good membrane momentary switch, if you can find one. There are also some switches with a rubber boot... not perfect, but sufficient for bike applications, I think.

regards,
Steve K.
(not to be confused with Steve the Bandgap :-) )

[sortafast]

Hmm.
I help run a bike shop with my stepdad, and the 10-20 dollar tail lights are what we do a lot of, and so we see various types come through on a regular basis. Right before christmas, we got in a new light from planet bike it looks to have 1 luxeon Led with a small optic and 2 5mm leds, but i havent torn it apart yet (i get yelled at for doing this to the lights). Its pretty small, but it might be worth looking into for you. For the last 2.5years, i have been running a cheap little $12 Serfas light, and i love that little thing. I have wrecked pretty good on it 2 or 3x and its still doesnt let water. only have to change the batts every 6-12mo.

But like Steve K said, your best bet (if you want to go DIY) would be to try to tap it into a main battery supply from the head light. I always thought it would be funny to hook up one of those 190 lumen luxIII's as a tail light and really get drivers' attention, but it would draw a bit of power. The real challege with the tail light is gonna be the enclosure to keep it away from the elements

[AndyTiedye]

If it's 5 blinking Luxeons in "chase" mode, you're only powering one at a time.

[wasBlinded]

Its not quite as bright as what you envision, but the Planet Bike ("Superflash", I think) has a very bright rearward fascing LED, might be a red Lux. Even on continuous, power draw is only about 120 mA, so even the AAA cells should last a long time, expecially on flash mode.

[greenLED]

damon, yes, I've thought of building my own red Lux-based AA light. The problem would be finding a suitable 0.55" converter that would power the Lux off 1 or 2 AA's and blink. (goldserve's FluPIC comes to mind, but that uses li-ion, at least until he refines the piglet).

bandgap, power issues is why I mentioned 123's or AA's, and dismissed AAA. I've modified a couple of Sigman's blinkies with 5mm red LED's that came off a street light. Yes, they're much brighter than stock, but that doesn't solve the issue I have with the flimsy cases.

Steve K, I love what you've done to the place! Building on your idea of using optics, using 3 Luxes with those 16x50º optics would give at least 120º of illumination (I'm accounting for some beam overlap), or even 2 Luxes (for, say, 90º beam?). Less Luxes mean less power is needed to feed them. Bare minimum would be 1 Lux with an oval optic, like you propose, but I'm not sure how useful 50º would be for lateral illumination.

I've read a couple of threads where the 555 switcher is used, but some people mentioned it wastes too much power. Are you aware of other blinking solutions that would not be as power hungry?

Sortafast, the one you're talking about is a Planet Bike Blinky Superflash Tail Light. The say it's a 0.5W power LED; the optic looks like a Lux, but it could be something else. If you could sneak a peek inside one of those, that'd be great (tell your step dad I made you do it, or something). I've been reading reviews on it, and it sounds really nice. My only concern is side visibility; with just 2 5mm LED's, and another LED pointing back, I'm not sure how much of a wide angle it might have (unless that optic already is one of those wide-angle ones).

Another off-the shelf option is the CatEye TL-LD1100. It runs off 2AA's and has 10x5mm LED's pointing in all directions.


But, back to the homemade stuff...

[n_den]

hey guys,

interesting thread. i don't bike but my uncle bikes everyday to work and complains alot about the hazards. so, i found a 556 timer ic laying around, and hooked up a red lux iii with a carclo elliptical optic to it, pushing around 800ma and WOW! this will absolutely get attention!

not sure how to take the pics or video, i may have to mount it far away. anyways, the 555 timer is small and only takes a few components. not sure about the bikes power supply. as, said earlier, not a biker.

just curious why is there no commercial product available? what would the average cyclist spend?

n_den

[greenLED]

just curious why is there no commercial product available? what would the average cyclist spend?

I really don't know. IMO, using Luxeons as rear lights might be seen as "too bright" by some people (there's reports that's the case with the Dinotte; they even tell you to aim it low).

I think part of it is the issues with powering a Lux (or more). Usually people just want to use AA or AAA batteries, and if you use a cluster of Luxes, you're pretty much stuck with using 123's or some sort of rechargeable battery pack (li-ion or Ni-MH). All this obviously increases the price, and people are used to paying around $12-35 (the local bike shop prices) for a "regular" LED tail light.

[n_den]

just got the 'what r u doing over there'? explained the process, and she said, 'that's too bright. u need 2 filter it or something.' 'they want to put 3 of those on their bike'!?

perhaps 1 would do. tried taking pictures and video, but my sony just doesn't do it justice.

working on packaging the thing now.

n_den

[greenLED]

just got the 'what r u doing over there'? explained the process, and she said, 'that's too bright. u need 2 filter it or something.' 'they want to put 3 of those on their bike'!?

perhaps 1 would do. tried taking pictures and video, but my sony just doesn't do it justice.

That's awesome. You are driving that thing at 800mA's, though. That's quite a drive level, even if done momentarily. Could you set the current to 350mA, or spread the 800 between 3 Luxes (I'm EE-impaired, so bear with me if it's a "duh!" question)?

[jch79]

Another concern of mine is, if you're going to spend this much money on a rear light (which I know I would!), even if you make the back housing and mounting parts out of aluminum, you're still stuck with using plastic if you want to get side visibility... and we all know what happens when (not if) you drop your rear plastic bike light!

I'm trying to think of a way to make a self-contained (no external battery pack) light that has rear and side visibility, without the use of brittle plastic...

I'm glad we're talking about this... my rear light is literally on its last leg! Another screw fell out last night, and some of the LED's are out!

john

[n_den]

greenLED, let me see what i can come up with. trying to keep the costs & parts to a minimum.

jch79, i'm thinking of using clear resin. the kind people use to embed spiders, insects, etc. this should spread the light and be pretty durable.

n_den

[jch79]

jch79, i'm thinking of using clear resin. the kind people use to embed spiders, insects, etc. this should spread the light and be pretty durable.

Interesting solution!!! I'm excited at the prospect of that!

[greenLED]

n_den's on a roll!

[AndyTiedye]

Make it out of TITANIUM!

I like the clear resin idea too.

[Steve K]

Clear resin is a lot like some of the harder potting compounds. The use of hard potting compounds has its risks.... mostly that as it heats and cools, the rate of thermal expansion is different than the components that are buried in it, and the expanding and contracting potting can damage parts. I'd keep the resin layer as thin as possible while still covering all of the components. Let us know how it works out!

Steve K.

[Timson]

This link may be of interest....


This thing uses a red Luxlll for 140 Lu.
It doesn't have emitters facing in different directions, but when something floods this much light out the back and onto the ground...who needs em'.

Try the link...DiNotte Lighting


Looks pretty awesome to me.

Edit - Just noticed that GreenLED has already mentioned the DiNotte light in post #3 - so has already ruled that out as an over-the-top price option.....I'll leave the link in as others (with deeper pockets) may be interested.


Tim.

[greenLED]

Here's one nice way of dealing with the "windows" on this light:
http://www.candlepowerforums.com/vb/...d.php?t=147583

[jch79]

If you drop something like that, chances are it'll crack in the corner.. it actually looks like it cracking from being tightened down too hard in one of the corners on a photo.

Although an interesting concept.

john

[n_den]

This is my ideal bike taillight:

• 3-5 red Luxes: 3 pointing directly back and 2 pointing sideways (or a at 45-60º from the other 3), or 1 pointing back and 2 sideways.
• 2 modes: on/blinking/"chase" mode - none of those silly 7 mode lights that do nothing but annoy me when I have to cycle through all of them 3 times to turn the light off...
• waterproof to 1m
• simple battery options - since I'm a geek, 123's will do, thankyouverymuch, but I don't mind AA's (no AAA's or external)
• small

Short of all that, does anybody know of a circuit that will drive 3-5 red Luxeons and provide flashing functionality?

using the KISS method, i've come up with this for the circuit as opposed to the 555 IC circuit:

• Driver: LuxDrive 3021-D-E-XXXX
• Control: Cheap off-the-shelf flashing LED & on/off toggle switch

on the work bench:
i'm using a 3021-D-E-1000 (you can use 350 or 700) it runs off of a 12v power supply and drives (1) Lux III-red & (2) K2's (don't have any spare reds), connected in series.

• connect the power and output leads of the driver to the power source and led array,
• connect one lead of the toggle switch to the power source(12vdc),
• connect the other lead of the toggle switch to the positive lead of the flashing led,
• connect the negative lead of the flashing led to the CTRL pin of the 3021 driver.

when power is applied the on/off switch controls the leds to flash or always on. to turn completely off, disconnect the circuit from the power source.

• cost of 3021 around $20us
• cost of flashing led around $3us
• cost of toggle switch around $5us

you can put it in your led array housing or keep it separate.

pros/cons: diy, cheap, quick & small / no control of flash rate, no chasing mode

well its a start. n_den

[65535]

I HAD a rear light form NiteRider and it was bright about 20 ultra high output 5mm red leds with 2 modes blinking and on. Easy use hold for on press for switching modes. Then it alogn with a battery pack and a headlamp got stolen. with bike.

[Bill]

I saw my son's DiNotte tailight over the holidays. It is extremely bright and looks like the photo on the DiNotte site (not the one on snow!). The light weighs little, works well on AA NiMH cells and seems durable. It is expensive, but I think it is a good value for safety during daily commuting.

Bill

[greenLED]

If you drop something like that, chances are it'll crack in the corner.. it actually looks like it cracking from being tightened down too hard in one of the corners on a photo.

The crack in the corner in that light was machining slippage, but you're absolutely right nevertheless; acrylic will crack under impact, which is the problem I've been having with my lights.


n_den, we need pics of that setup! I think you've taken many steps in the right direction. Can that circuit be powered with anything under 12V? I still would like to keep the batteries internal, if at all possible.

I saw my son's DiNotte tailight over the holidays. ... I think it is a good value for safety during daily commuting.

Yeah, I've drooled over that puppy almost as much as I drool over HID light packages... but purchasing one ain't gonna happen on my budget.

Your post got me thinking, though... how about modding a PT Eos? A red Lux is pretty much a direct replacement. Plop in a wide-angle acrylic optic and we'd be one step closer to a good rear light. If a crafty CPF were to make a somewhat translucent plastic polymer case exactly the same shape and size as the Eos's, we'd tackle the side-ways visibility. (There are some plastic polymers that can be molded at home with relative ease.) What do y'all think? An attachment thingy-ma-jig would be an issue, though...

So many mods, so little time!

[jch79]

Your post got me thinking, though... how about modding a PT Eos? A red Lux is pretty much a direct replacement. Plop in a wide-angle acrylic optic and we'd be one step closer to a good rear light. If a crafty CPF were to make a somewhat translucent plastic polymer case exactly the same shape and size as the Eos's, we'd tackle the side-ways visibility. (There are some plastic polymers that can be molded at home with relative ease.) What do y'all think? An attachment thingy-ma-jig would be an issue, though...

Wow - great idea! However, the strobe on the EOS is a little too slow for noticibility IMHO... I wonder how difficult it'd be to put a FluPIC or Piglet board in there?

Does anyone have the EOS bike mount that they can see how it rigs up to the vertical seat post? I'm assuming it'd be ok, however it's designed for the handlebar, and I don't know if it puts it on an angle that'd be weird for the bike post.

greenLED - I think you're on to something.

I bugged "Light & Motion" - an American-Made bike light company (www.bikelights.com) that makes some awesome HID lights & one LED, to see if they'd make a rear LED light, and their answer was:

"This is something our development team is looking into, however I would not expect to have one available for this upcoming light season."

So whatever that means!

john

[jch79]

I was looking at PT's website, and noticed that they also made the Aurora into a bike light... this has 3 LED's, and I wonder if it could somehow be modded to have them in chase mode.. ?

It's also a way more simple design than the EOS - so it'd be simpler to mold or even possibly machine? And the clear plastic covering the LED's already protrudes a bit from the body, which means side visibility is already there, however not as much as I would like, so perhaps a new window could be made?

One possible drawback of this light right now is that it has 5mm LED's, which would have to be swapped out for Cree XR-E's or Seoul P4's.

Just an idea!

john

[n_den]

i'll try to get some pics and vids of my project. the flupic sounds pretty good. how much? Vin/Max current? better yet, anyone point me where to go for more info, please. i know, do the search thing. typed flupic and there's too much to go thru. tia.

the idea about using existing housings has also crossed my mind. may be cheaper than trying to custom the whole thing.

n_den