LED on a timer?

[copperfox]

Is there any driver or easy-to-DIY electronics that can supply power to an LED based on time of day? I have an idea for a project that would require an LED to ramp up in brightness in the morning (taking maybe 30 minutes to go from off to full), stay on all day, then ramp down in brightness at the end of the day and stay off all night.

I know they have those plug-in light timers like this one, but ideally I'd like one that doesn't just turn on at full brightness, but one that ramps up over a short period of time to mimic the rising and setting sun.

I am thinking of using a high-CRI SSC P4 emitter.

 

[TorchBoy]

Is there any driver or easy-to-DIY electronics that can supply power to an LED based on time of day?

Yes. It's called a solar panel.

:thumbsup:

 

[VegasF6]

Sort of like these?
http://www.thecompletesleeper.com/Soleil_Sunrise_Simulator_SA-300W_Controller_p/109004.htm

I don't know how you are going to work that with an LED, but still, interesting.

I think it is going to require a custom circuit utilizing an optocoupler to drive a triac or something, and the national LM3445 triac dimmable driver would be nice.

I tried to google optocoupler triac dimmer, came up with some discussions about it, but no schematics. However, I am sure it can be done, and not too hard.

In fact, here is an article about almost exactly that:
http://www.edn-europe.com/legacytriacdimmerscandriveledlampacdccontroller+article+2932+Europe.html

 

[VegasF6]

I found some more links you might enjoy.
http://www.instructables.com/id/LED-Sunrise-Alarm-Clock-with-Customizable-Song-Ala/

http://www.instructables.com/id/Blue-LED-dawn-simulator-for-Soleil-Sun-Alarm/

http://www.instructables.com/id/A-sunrise-and-sunset-lamp-with-LEDs/