Designed to be compact yet bright enough to ride by, these lights used a driver of my own design and construction, controlled by a PIC micro controller. They featured two brightness levels and a battery monitor to indicate the charge status of the battery. The inspiration for these was partly from the series of adventure races in which I competed (the Challenger World series), where handle-bar mounted lights were not allowed.
For this design, I designed and made up my own surface mount PCBs, soldering the components in place under a microscope. I also developed and loaded my own software for the PIC. I must have had more time on my hands back then!
The aluminium tube, containing the lens, LED and the PCB controller, is 25mm diameter and about 45mm long. Only a battery needs to be added.