I am trying to figure out how to operate a solenoid on loss of sunlight so that I can drop an insulating panel into place over a Trombe wall after roughly 3PM every evening in winter. I guess I could use a low voltage DC circuit to operate a relay which then operates the higher voltage DC solenoid circuit. How do I de-energize the DC solenoid circuit so that I don't run the battery down? I have zero electronics experience. Any help would be welcome. Thank you.

 

Typical way to put a system in standby is a limit switch activated when operation is complete.

Need a lot more information about the mechanics.

 

Yard light timer.
Or block heater timer for a daily fixed time operation.
Is there AC power available?
Max.

 

Unless cloudy day operation is needed, timer makes more sense.
Or temperature maybe.

How will a solenoid move the panel?

 

Timer would be OK. I saw a thread about using a kitchen timer hooked to a 555. Could use that concept but would have to use a 24 hour clock. The solenoid would merely release the insulation, which would fall and cover the trombe wall. I figure it's a way to boost the efficiency of the wall's heat transfer into the house. I can't get out there at 3PM myself everyday. 3PM is recognized as the cutoff time for solar heating for a vertical trombe wall. Thanks for the input. I've got a lot to learn.

 

I'd like to stay away from AC. Would like to use battery and solar power to recharge the battery or merely to move the solenoid.

 

The solenoid would pull in and release a wire. Gravity would do the rest. Thanks.