I found a good looking Twemco flip clock. Unfortunately the unit is only a slave without control unit. The unit works with some type of two position “step motor”. If you supply the unit with +24vdc impulse, the minute changes. Then you need to supply -24vdc impulse to get the next minute. And then again +24vdc… I tested this manually with power supply and the clock works perfectly.
I read the instructions on http://arduino-info.wikispaces.com/ArduinoPower. Based on examples on that page I think my project can be solved with Arduino, relay and 24vdc power supply. Am I right? And an open issue is how to make the – and + change, do I need two relays (one supplying – every two minutes and other supplying + every two minutes?)
I would appreciate if somebody could guide me how to approach this project.