watch winder project

Hi

I would like to make a watch winder (to keep an auto watch runing). I have made a simple one already but would like to have a go at a more sophisticated one.

For my next one i intend to use a dc motor with gearbox that will rotate about 8 rpm (i have seen a 12v one). I would like it to rotate in one direction for a period of time, stop and then reverse for the same period of rotation.

The period of time is not critical as auto watches cannot be overwound. The more sophicated bought models rotate for about an hour in each direction with a few minutes pause inbetween then stop.

I have a very limited knowledge of electronics but am practical, can follow instructions and can solder. I have gleaned some information fromvarious sources and have been told:

a 555 timer would do the job
long run and pause periods are not practical because of the resistors and capacitors needed.

If i could make one that would run for a few minutes, pause for a few seconds and reverse for a few minutes that would be great. If it could do this for about an hour and turn off that would be a bonus but i am aware of my limitations.

Thanks in advance

Gary

You need two different signals, one to turn the motor CW, and the other to turn the motor CCW. These signals would be used to drive an H-Bridge which reverses the current through the motor.

I would use a 555 astable (oscillator) running at a period of 5 minutes. Use the 555 to advance a CMOS 4017 counter which counts 0-9 with decoded outputs. Use count 1 as CW, and count 3 as CCW. This gives you a cadence of 5min of CW, 5min of stop, 5min of CCW, and then 35min of stop. Both the 555 and the 4017 will run off 12Vdc.

Mike

Thanks for your reply. At 8rpm i need to rotate for about 2 hours to fully wind. It would be better to wind in each direction (5 mins?) with a few seconds break between. It also might be better for me if it kept going and i turned it off after a couple of hours.

Thanks again

Gary