Solari clocks

I am new to Arduino and this forum. In fact I have not yet bought a board or built a project. But I have read books, understand how Arduino works and that it should work for what I need. After years of looking, I finally bought a Solari clock. Mine is from a German train station. After some investigation I found out that it changes minutes with a 24VDC pulse, with a 1-5s duration. At the next minute it requires another 24VDC pulse, but this time of opposite polarity, -/+ if you will, because of the synchronous motor it uses. So I need to build a board which provides a 24VDC+/-, 24VDC-/+, 24VDC+/-and so on pulse. This will require relays, triacs or SCRs. Two questions:

  1. Is the crystal on the board accurate enough to be used as a clock? I am not looking for "atomic clock" precision, just something that needs resetting may be once a year. Alternatively, I suppose, the board can get its signal from an internet connection to be more accurate. Ideally it should also go forward an hour when "daylight savings" happens and stop for an hour when "standard time" returns (the Solari cannot be made to go backwards). Again, these would be nice but not crucial.

  2. Has anyone built such a circuit? While I have built many circuits in my life, now, as a middle-aged man with a family and a full time job I am not sure I will realistically have the day or two to design this myself. Is anybody in the community interested in developing such a circuit for me, of course for compensation?

I will appreciate any responses.

Maybe this - - is your ideal board. The owner of that "shop", RuggedCircuit, is an active forum member, so you might PM him on this one.


I'm thinking you could accomplish this with an H-bridge motor controller... to give you your +24/-24vdc; controlled by an arduino. you could even syncronize the time by parsing data with a gps module and/or a WWVB reciever like this one...

Sounds like an interesting project, keep us informed on how you proceed!

I want one of those flip clocks so much :D