X-Light II

Copyright © 1996 Jørn Yngve Dahl-Stamnes

Last modified: December 5th, 2001

Introduction

After the X-light was stolen from my bike (while parked in the basement where I lived at that time), I began to design a new light - the X-Light II. The major goal when designing this light was that it should be easy to remove. If the light was as easy to remove as a bicycle computer, I could remove the light when I parked my bike. This will prevet the light from being stolen.

To make a light that could be removed and installed as easy as a bicycle-computer require that there was no wires between the light and the battery and switch on the bike. It took Kolbjørn (who helped me make the light) and me a few weeks to find out how to make a "wire-less" connection that would work in all kind of weather conditions and that would not break after some use.

The X-light II unit

Just as the X-light was made from an aluminum tube, the X-light II also use an aluminum tube machined to fit a 20 Watt halogen bulb with a built-in reflector. The other end of the tube is closed by an aluminum plate.

The design of the X-light II is more or less a copy of the X-light. A plexiglass, a rubber gasket and a locking ring keep the bulb in the tube. The unit is not 100% waterproof, but it should resist rain and snow without much problem. Sofar I have not had any problem with water inside the unit.

The major difference between the X-light II and the old X-light is that it can be removed from the bike. This require a mounting bracket fasten on the bike. A small aluminum tube is mounted under the X-light II. This tube fits into a hole in the mounting bracket. A screw with a wing-nut on the bracket is used to secure the X-light II when mounted. By tightning the wing-nut, the hole get narrower to fasten the light.
Inside the tube is a small female power pin insulated from the tube. The power pin in is covered with gold to prevent corrosion. A gold covered male pin is located at the bottom of the hole in the mounting bracket. This pin is connectedt to the power switch.

With this solution it takes me only a few seconds to mount the X-light II unit on my bike (if I use more than five seconds my hands must be very cold!). I do not have to think about connection the unit to the wires on the bike.

Power to the light!

The X-light II is powered by a 12 Volt 3.4 Ah sealed lead-acid battery. A fuse (2A) and two connectors are mounted on the battery. The battery is placed in a water-bottle cage. The battery can easily be removed by disconnecting the wires and taking it out of the cage (just as you do with a water bottle). Even if the battery isn't round like a bottle, it fits very well in the cage as if it was a round bottle.

The power wires go from the battery to a main switch on the handle bars. The switch has three positions: On - Off - On. In the first on-position The X-Light II will be on. In the other on-position the old bicycle light is on, which saves energy on longer tours. In both on-positions The X-Light LED taillight is turned on.

Thanks to Kolbjørn Lindgjerdet how helped me with the light. If you have any questions about The X-light II, please e-mail me.

Long-term usage

Over time, the gold layer on the power pins was worn out. Several (dis)mounting caused the gold to disappear. This caused bad connection. After a few years I had to install a female bannana plug at the end of the housing for supplying the bulb with power.

Images

The unit Front view.
The unit Back view including the power switch.
The battery pack mounted in the water bottle cage.

Drawing

Electrical drawing Show how things are connected.