Bicycle Lighting


LED lights

I have this configuration working on 4 bikes. Generally it is two LEDs in series, each series string in anti-parallel with each other for a total of 4 LEDs per dynamo. I've even experimented with optionally adding a supercap across *one* LED in each string to work as a standlight. If you add a supercap across every LED, your system won't work optimally and you'll need to resort to a bridge rectifier or other blocking diodes to regain the advantage.

The red LEDs I'm using are Luxeon Star/O with rating 2.85V 385mA. The white LEDs I'm using are Luxeon Star/O with rating 3.4V 350mA.

I did at one point use a Luxeon V Star which was twice the current and twice the voltage. These work fine on dynamos that don't have any protection electronics, but there is one that I have that is clamped at just over 7V so for that dynamo I had to put the string in parallel.

Since the rated output of the dynamo is on the order of 500mA, it is delivering effectively 250mA per string (500mA half-wave) since it is self-rectifying.

They are bright, flash at low speeds, which is fine, and flicker less at higher speeds, which is also fine.

I've made my own head and tail lights from 18AWG lamp cord, 1.25" compression plumbing drain fittings, a back cap and the discontinued Luxeon Star/O 1Watt LED. I use two white LXHL-NWG8 on the front and two red LXHL-ND98 on the back.

I'm now switching over to something like the Luxeon Rebel Star in red (generally) and Luxeon Rebel Star in Neutral White (generally) using the Fraen Elliptical Lens with holder, all available in Canada through Future Electronics.

Dynamos (Dynohubs)

I've been using a Shimano HB-NX60 front hub dynamo for a number of years now and have been extremely pleased.

I found a good value in a front dynohub in the Novatek hub from TallTree Cycles on Richmond Road near Tweedsmuir for $50 (now $65, 2011-06-08). I plan to get more. What I am currently using for dynamos are:

I'm about to purchase another four Shimano DH-3N72 dynohubs to equip more bikes.

I never need batteries and they are visible a kilometer away.

More recent designs have added a 1Farad supercap to make a German standard standlight.


Other resources


Thank you to Martin Hicks and the BikeCurrent mailing list for provoking this writeup.

(previous bike lighting writeup)

(C) 2002 Richard Guy Briggs Web Page last updated by Richard Guy Briggs Tue Dec 11 21:24:01 EST 2012