I would say, you need a time clock, a reversible gear motor, with limit
switches and whatever mechanical attachments needed to connect to your door.
I'm wondering if it wouldn't be simple enough to adapt a garage door opener
to the task



wrote in message
oups.com...
What do I need (relays? gears?) to have a small electric motor turn on
via a timer, run for the few seconds needed to raise a small (10 x 14
inch) piece of wood via string and pulley (door to a chicken coop),
turn itself off, then turn on again via timer hours later and run in
the opposite direction to lower (close) the door and turn itself off
until it's time to tbe turned on again? This seems to be on the
principle of a garage door opener, only smaller and opening/closing on
a timer switch instead of a push-button or transmitted signal, right?
Are there systems like this already in existence?

Thanks.

Lynn Willis
Indianapolis