Friday, May 12, 2006

DIY Bike light systems

Have been thinking about upgrading my bike's lighting system for a while, as I have a Cateye HL-EL300 at the moment. It is apparently one of the first LED lights to meet Australian standards. It has 5 LED's that are very directional, and as I found out a few weeks ago on a rainy night, no real side visibility (a car didn't giveway at all).

DIY LED Luxeon lighting

I was initially looking at the DIY high power Luxeon LED's. I can't remember what got me thinking this, must of seen a mention of them at one point (maybe seeing the new Cateye double/triple high power LED lights, costing upwards of $450AU !!)
Update: My Google search History shows I hit the Wikipedia bike lighting page when looking up details for a Powerbeam halogen headlight from Torpedo7 (great site).

  • Wikipedia article: Bike Lighting
    As always, a Wikipedia article that is a good introduction to the subject that covers it broadly. It used to have ~4 links under the "Home Made LED lights" section (since removed):
  • 3W Luxeon bike light
    Very well made (and machined) LED light system, if only we all ad a lathe handy. Include a design diagram as well!!
  • 3W Luxeon bike light
    Another Aussie one, this time with parts straight out of a hardware store. Nice a cheap option, using some plumbing PVC pipe and heatsink from an Electronics store. A little dodgy though, like holding the batteries in a cut up VHS case and the switch just hanging, but then again its cheap, and the article provides heaps of construction details and part numbers.
  • DIYcycleLEDs Wiki
    A nice page detailing the prototyping & construction of 3x 3W Luxeons using 12x 2000mAh NiMH batteries (about $60AU worth). Nice photos and going into the finer details.
  • Twin 5W Luxeon bicycle lights MK2
    A whole series of articles, from the prototype to 3 different version. Given the detail that these articles go into & technical quality of the approach, I was thinking of following this route. Though maybe use 2x 3W Luxeon's, as they seem easier to drive and keep cool (& therefore service life).

Even Silicon Chip had an article on a Luxeon LED driver circuit.
Update:They now have a article on "Universal High-Energy LED Lighting System" which specifically uses a bike (a recumbent) as the example system, need to check it out big time!!!

Update (2006-07-11): Found the High-power LED mountain bike light page. Another Aussie LED project (are they all) so includes some good suppliers. Some nice design ideas here, especially the AA NiMH bottle.

DIY Halogen lighting

Then I stumbled on the Bicycle Lighting Systems page by Steven M. Scharf. It goes into so much detail (especially technical and sourcing parts) its scary. This site seems to have convinced me that a DIY Halogen system might be better and cheaper than a DIY LED light system. I think it was the "Watts Versus Lumens" section that convinced me of that, with the table comparing Halogen, LED and HID. Also the 5W LED Luxeon's sound as if they have a short life span. It also helped me reach the conclusion that for my night time commuting (with street lighting), it is better to be seen rather seeing (especially after the above mentioned close call)

Particular sections that are good are:

  • Seeing versus Being Seen
  • Watts Versus Lumens
    Includes a table of common Halogen (MR11 & MR16) globes, High power LED's and HID (High Intensity Discharge). It also includes data for when over-volting Halogen by 10% & 20% (it improves the effeciency, but trades life)
  • System Recommendations
    My current theory is to follow this almost spot on with:
    • Globes: 2x 20W MR16 Halogen (hopefully a 7/8o and a 24o, but sourcing is hard)
    • Headlamps: Cheap, compact set of car halogen driving lights, as the housing (turf the 50W globes)
    • Battery: 12V 5-7Ah SLA, hopefully housed in the bottle cage near the bottom bracket
    • (Thinking in future) a Xenon rear flashing light (like on trucks/trailers)
  • Headlights
    Has so many details about MR11 & MR16 Halogen globes it's not funny. Also includes the options for the headlamps, mainly different car driving light sets.
  • Batteries
    Includes discussion of choosing a battery system, includes techincal data and equations. Goes through the pros & cons of SLA and NiMH systems (NiMH are good for over-volting Halogens). Also talks about housing the battery on the bike.
  • Charger
    Again a discussion of the different types, models, requirements and options. Talks about a few DIY system additions, but nothing concrete.

While looking for sources of Halogen globes in Australia for Bec's NiteFlux Visionstick 5.5 (a MR11 6V 5W 10o that I can't find anywhere except $$bike shops$$), I found a link to another DIY Halogen system from a web forum.

the fat hippy's home made bike lights is an Australian site so the details of sourcing parts should be very useful. It shows 5 different iterations of the system, including part details, costs and sourcing. It also comes to the same conclusions as the Bicycle Lighting Systems page and myself :)
The tow bar cower housing seems pretty good, except for the hose clamps holding it together, kills the look if you ask me. But this page really is great, it goes into lots of the kind of details I like. The last version (Mk V) even has a digital controller circuit which uses one button to control the power and sounds like it helps a battery last longer.

Update: Just discovered the bikecurrent FAQ page from fat hippy's site. Seems very promising, with lots of details, equations, pros/cons of choices and many links to other sites.

Update (2006-07-11): Found the BIKE LIGHT 500 Lumen "Mt.Bike" for under 10 bucks by Veggiecycle page. Another great article on using products from hardware stores (Home Depot so US). The comment section is also good, with some useful links such as Home Depot Homebrew Headlight, using Landscape Spotlights and which has a great range of Battery packs, chargers, leads, mounts & bike light systems.

Update (2006-07-11): Found the Beenz Meanz LIGHTZ ???!!! page. While tin cans seems a little cheap, there's some great thrifty ideas here.

Globe sourcing

Had lots of trouble trying to find Bec's globe, as well as the one I want. Couldn't find a website (mainly US ones via Google) that had the globes I wanted (none had Bec's) for a good price that shipped to Australia :-(
Bec's globe: Halogen MR11 6V 5W 10o (ANSI code = FTB for 10o)
My globes: Halogen MR16 12V 20W 7-8o (ANSI = EZX) and 24o (ANSI = BBF)
Did find the following:

  • GMT Lighting (03) 9819 1777 Hawthorn
    MR16 in 13o (ANSI = ESX) for ~$10 (GE 5000hr model)
    MR16 in 38o for ~$8
    MR11 in 30o for ~$10 (FTD - Wide Flood maybe?)
  • Lamp Technologies (03) 9874 8100 Nunawading
    MR11 in 30o for ~$11
  • Koala Wholesale Lamps (03) 9326 8244 West Melbourne
    MR16 in 15o for $9.5 (GE)
    MR16 in 36o for $6.95
  • Calmatronics (03) 9326 5888 West Melbourne
    MR16 in 10o for $4 (Osram)
  • John R. Turk (03) 9318 9955 Yarraville (also in Fairfield
    MR16 in 12o for ~$2.5 (Compton)
    MR16 in 24o for ~$2.5 (Compton)
    MR16 in 38o for ~$2.5 (Compton)