Side glow cable with LEDs

Many projects require illumination.  An LED is often a good choice because it can be bright while using a minimum of current.  An ultra bright LED can even drive enough light through short lengths of side glow fiber optic cable.  This cable is flexible plastic cable with a reflective core to direct light to the side, as opposed to simply transmitting the light to the end of the cable.  While it is designed to be used with bright halogen bulbs that push light through hundreds of feet of cable, I was interested to see how well an LED could work with just a few feet of cable.

My wife and I are interested in making safety clothing for night bicycle riding and thought this might be useful. We ordered a five foot section of 3mm wide cable from here. Once I had the cable in hand, I attached a bright red LED to each end with shrink tubing.

End connections

A quick test shows that two LEDs provides a fairly even glow along the entire length of the tube. Each LED was rated to deliver 18,000 millicandelas of light.

Two LEDs powered up

This looks like it could be used on a bicycle helmet to provide a flashing illumination. More to come as we experiment.