And once that 'jerk' has gotten it off the switch lever will it continue to spin? I'll increase the cap and try to manually test it.
Yes, as once the switch releases, its NC contact holds Reset low (no reset) so the motor stays running (for up to 15 minutes), while C1 continues to charge so the switch can reset the '4060, stopping the motor, when its next hit.
Wow! This is great!
Works as intended now: the 10uF gives it a strong enough 'jerk' so it slides off the lever, then continues to spin 180degrees until it stops and rests on the lever.
Thank you very much for all your help Ian!! Your knowledge as help was invaluable.
I will post pics with the final result.
FINISHED!!
I built the circuit and after some mechanical and electrical tweaking it works exactly how I envisioned it.
Video of the spinning hourglass:
https://thumbs.gfycat.com/ZestyBlushingCoral-mobile.mp4I've added a few additional features:
- test mode switch: to switch between the 1 minute delay pin and the 15 minute delay pin;
- power switch
- female micro USB: to trickle charge the 3 NiMh batteries (via a resistor and diode)
- solar panel: used as a base and also charges the batteries via a Ge diode
For some reason, I built it with only 3 NiMh batteries in series, which don't give enough power if they are a bit discharged. Will add the 4th to give it more oomph and longer running time.
I am very happy with the result and it works very well and looks quite nice too.
Depending on how it works long term, I might replace the NiMh batteries with a used cell phone battery since it has a much larger capacity and it's easily charged with a small and cheap TP4056 based battery charger board
Thanks again to Ian.M and others for the help!