In the old days, if you wanted lights on your bicycle, you headed off to the corner bike shop. There you equipped yourself with a "dynamo" (actually, an alternator) and front and rear lights, both of which used incandescent light bulbs.

These days, however, generator-powered lighting systems are out of fashion, replaced by flashing front and rear LEDs powered by standalone AA cells. Which is fine if you don’t really want to see where you’re going and you don’t really want to be seen by other road users!

The main components of the author's bike alternator system are clearly shown in this photo: (1) knurled aluminium roller made from a video drum (the white centre cap is from the top of a vitamin jar); (2) alternator support frame; (3) stepper motor (used as an alternator); (4) cover over end of video drum bearing (the cover is the cap from a deodorant bottle); (5) bearing support and (6) bike support frame.

OK, that’s not quite the case – there are some excellent high-intensity LED tail-lights available on the market. And as for seeing where you’re going, if you’re rich, miniature halogen headlights with their own rechargeable battery packs can be purchased.

These latter systems, some of which retail at $300 or more, provide excellent illumination but there‘s a downside – the battery pack needs to be frequently re-charged. In fact, if you ride for more than an hour at night, the battery may well have insufficient capacity to last the full length of the journey. Even Luxeon LED headlights and tail-lights (see the "Universal High-Energy LED Lighting System" in the April & May 2006 issues) are limited in lighting duration if you’re away from a mains or car power source.

In short, if you want a lot of light over a long period, you must either carry a heavy battery pack or, alternatively, generate your own electricity as you ride along.