What's New
- iriver Lplayer teardown
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- Robotic locomotion
- Finding value in work
- ZFS: the final straw
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- Running AbstractSpoon ToDoList under Wine
- Aoyue 906 Hot Air Rework Station review
- What I learned from setting up ZFS on my fileserver
- Nokia E65 review: how does it stack up against a 5-year-old Siemens ME45?
- Extending battery life on the Dell XPS M1210
- A quick guide to using MySQL in Python
- Market segments and tactility: the new Apple iPhone
- Cree XR-E LEDs
- What's New block for Drupal
- Google calendar for Sydney adventure and MTB races
- Background Check Antivirus
- Multithreading and performance
- DVI on laptops
- Dell XPS M1210 review
- Improving university for developers
- Automatic Wealth for Grads, by Michael Masterson
- Converting Access databases to PHP/MySQL webapps
- Testing the board
- Assembly
- Making a PCB
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- One weekend, one PCB layout
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- Introduction
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- Integrating the H-bridge and its controller
- Using CPLDs and FPGAs in hobby electronics
- A simple logic analyzer
- I2C-based H-bridge controller with PWM
- The virtues of small development teams
- Building a Sumo robot (summary)
- High-power LED mountain bike light
- Optimizing your Start menu for fast program access
- The best batteries in the world...
- Battery-powered USB iPod charge cable that requires no special components
- How to build a simple Luxeon LED bike headlight
Cree XR-Es work well
Hi Ian,
I've also been building LED bicycle lights. I just upgraded my single Luxeon III to a Cree XR-E with Fraen FC optics. The difference is impressive, as shown by the beam shots. A triple XR-E light will be brighter than a 20W halogen. I did this test on the weekend and the results are
http://www.ghostgum.com.au/misc/BikeLight.htm
Note that some of the info I wrote in a previous comment on your blog is no longer current.
http://www.mouldy.org/projects/Ultimate-Luxeon-K2-bike-lights
The data sheet for the XR-E has changed. 1A drive current is now Ok, but with reduced efficiency. The beam width is 90 deg not 75 deg, so the older 7090 optics should be Ok.