Hey guys,
I've been enjoying these forums for a while now, but have yet to find anything that can solve my dilemma. I will try to keep this short and clear.

I am trying to build a clock where the hands move once per their respective unit...i.e. the minute hand moves once and only once per minute, same with hour hand. Basically I want the minute and hour hands to move like a second hand does. Again, hour hand to move 30 degrees in one swift movement every hour, minute hand to move 6 degrees in one swift movement every minute. The only clock I have ever seen that does something similar is those old oven/stove clocks. They roll once per minute and hour.

So, I have read and thing that stepper motors may be the best way to go, but I don't know about a microcontroller, or which motors to use, or which programming language to use. I would like it to be very precise, so do I need to use some chip that contains a quartz. Or has anyone ever uses the chronodot?

See guys I'm green....super green. I would really like to make this clock and spread the word to ohers on how it can be done. Thank you so much for your patience and you help!!

Charlie

 

Quite a challenge there. Yes, I'd agree that steppers are the way to go. But think of the output--you need 3 concentric drives, each operated by its own motor. Little timing belts to run it, maybe?

I'm familiar with the PIC processors, and one of them could certainly do the job. They can get a timing signal off a 32KHz watch crystal, if you need accurate timekeeping. Other people will say their favorite processor is the best, and maybe they'd be right.

An additional complication you have to worry about: how does this clock get set to a known starting time? Steppers don't have any way to move to a particular place, so you'd have to have sensors on each drive system to tell the processor when the hands were at (let's say) 12:00:00.

This project combines mechanical and electrical engineering, plus software. It's, uh, a challenge.

 

Another way to do this is with the use of an intermittent drive mechanism - http://en.wikipedia.org/wiki/Geneva_drive