A (mechanical) clock ? With a slight 2:1 mod for 24h? As most small equatorial mounts have.

I think that an equatorial Mount with Step Motors for training and Elevation might be the case. It has been used for Sun-Tracking by the ARTEMIS-IV radiospectrograph. I am not sure if the system is low power (it uses standard 220 V grid power) but step motors come in all sizes... this been said, we must take into account that ARTEMIS-IV works unattended, so the elevation step motor is used once a day for setting declination. For more details (and technical description) see :

http://web.cc.uoa.gr/~artemis/

Best will be if you use a drive with a small integrated motor with

built in gear drive or planetary drive.

See the motors and drives we used in our system (detail in Annexure):

https://www.researchgate.net/publication/260844761_Automatic_positioner_and_control_system_for_a_motorized_parabolic_solar_reflector

Thesis Automatic positioner and control system for a motorized para...

Dear Shrikant, I am curious to know if you found any other motors. Will be interesting to learn if there is something better. Regards, Gerro

I recommend analog servo motors as they are cheap and provide high torque and can be easily controlled.

My experience with the TowerPro and Futaba motors was very good.

Conference Paper A Cost-effective Microcontroller based Sensor for Dual Axis ...