Anybody controlling lights with photocell?
 

I have a grow chamber that utilizes 2 48" LED light strips. The lights are on a battery backed-up timer. The set-up has been running for close to 3 years. I try to adjust the on-off times to "somewhat" match the seasons as this seems important to the Cattleya's and probably the other plants to to some degree. Naturally, I am fairly lax about resetting my timer, which maybe gets done 2-3 times a year.

It seems that ideally, a photocell device that simply turns ON the lights when DAYLIGHT is detected, and OFF when DUSK is detected would be ideal.

Does anybody know if something like that exists? Has anybody designed something like that? I. E. Photocell to AC relay arrangement.

Thanks,
Joe

Small screw-in-socket devices exist for porch lights. I'm not sure how you could adapt one to a terrarium some distance away.

There are also computer-controlled switches. You could program one to turn the lights on and off at sunset and sunrise anywhere on Earth. For orchids, most of which originate much closer to the equator, you probably don't want a day length similar to Iowa in the winter.

They switch the power just the opposite of the OP's request - on at dusk, off at dawn, rather than matching the sun's normal light/dark cycle.

Like you, I think Joe is overthinking it. Using a simple timer to set on/off hours is sufficient, adjusting it twice a year for different day lengths is sufficient, if necessary at all.

I agree for OP's application, but one idea I had was to use a photocell to turn supplemental lights on for cloudy days only. I'd also turn them off when the sun sets, because while lights during the day are fine, grow lights in a window can be quite annoying for pedestrians if you (like me) live at street level in a city. They also draw unwanted attention if you live in an unsafe neighbourhood like I do.

I did overthink this, and am probably sure my orchids would not really like an Iowa latitude day/night cycle. Thanks for the feedback. I'll find something else to overthink.

Hah! It's an easy trap to fall into!