This clock concept uses big dominos with changing faces to display the time. As far as we can tell they haven’t made it through to a finished product yet, but we loved the explaination of the engineering that went into the prototype. After the break you can watch [Eric] explain how he accomplished the design requirements of a slowly changing digit that uses no power to keep its state, which also uses low-power when changing state. To accomplish this he designed a flipping circle that stays put in both the white and black positions once set. When it’s time to change the digits, a coil is energized to push against a magnet in what he calls a single poled motor. Whatever the name, we want to build one ourselves!