Like many of us, [Tim]’s seen online videos of circuit sculptures containing illuminated LED filaments. Unlike most of us, however, he went a step further by using graph theory to design glowing ...

Before we describe how it’s done, note that we recommend that the result be checked as having sufficient brightness for a stop & tail-light application. That’s because the light output may be ...

This device was designed on request; to control the light intensity of four filament lamps (i.e. a ring illuminator) powered by two AA or AAA batteries, for close-up pictures with a digital camera.