I'm looking for a simple circuit that would drive a large number of LEDs for a sunrise simulator. It would obviously have to be able to perform a long fade up phase, up to an hour.
Have looked at various circuits, including Bill Marsden's excellent posts, but not managed to think of anything I could work with, fader wise. Could anyone point me in the right direction?

 

Hello,

You could have a look at PWM control with a counter and a DAC for the control voltage of the PWM.
For instance a 256 step counter will raise the voltage on the DAC about every 14 seconds.

Bertus

 

Even a lowly Arduino has PWM'able pins with duty cycles ranging from 0/255 to 255/255 at a frequency of 500Hz. A 14sec delay is trivial.
I could write the code in ~ 5min.

 

Thanks for your replies!
The oscillator - counter - DAC approach seems a bit too complex for me.
Have more experience with web development than electronics, so perhaps an Arduino with a MOSFET would be the easiest solution after all? Would an Arduino mini or nano be enough? I am just looking for anything with PWM capable output right?

 

A nano is quick and easy. The mini would do it, but requires a bit more wiring. If you need to build ten of them, do the development on a nano and incorporate minis into the final product...
If you need a thousand, learn how to program an ARM or PIC.