I have used the 4017 decade counter for a number of projects in the past and it's perfect. The trouble is that for this job I need to make a rotary indicator like a clock and I need to count to 12 or 16 (something that easily divides by four).

I've routed around the internet and I can't find anything suitable .. There is an octal version of the 4017 (4022?) so in theory I could make a circuit to use two of them to make 16. But if anyone know of an off the shelf solution it would be perfect ..

 

You need a 4-bit binary counter something like a 40161B (although there are other types) followed by a 4 to 16 line decoder like the 4514B. For 12 outputs use 0 - 11. You can make your counter reset to zero at 12.

 

You need a 4-bit binary counter something like a 40161B (although there are other types) followed by a 4 to 16 line decoder like the 4514B. For 12 outputs use 0 - 11. You can make your counter reset to zero at 12.

I ended up using a HEF4514BP (simply because of easy availability) .. It works perfectly ..

http://www.portablemotioncontrol.com/usync.html