I live in a place where there is little daylight in winter, so I would like to use a light therapy lamp. Also, I would like to use it to wake me up, gradually increasing the intensity of the light over a preset time, starting at a preset time. There exist light alarm clocks that do just this, but they are way darker than a light therapy clock, so I would like to combine those two functionalities.
My idea is to buy a simple light therapy lamp that is on/off only and create some kind of controller circuit that varies input voltage according to my settings, possibly with a mini-computer to get the alarm clock functionality.
The features I would like to have:
- a gradual increase of light intensity (doesn't need to be smooth, 5 steps or something like this are fine as well)
- some kind of control buttons so I can turn the alarm/the light on and off as well as change the alarm time (it is okay for me to use my computer to change more advanced settings, but I would like to be able to do these ones directly)
- ideally some kind of display/led combination to show me alarm time
- as little as possible stand-by energy consumption
- as cheap as possible
- not overly complex - I have little experience in electronics and would still like to understand and build the circuit. I have some knowledge in programming and feel comfortable to implement an alarm clock software in an Arduino/Pi etc.
I know that some of the features could be mutually exclusive. It's just to give you an idea of what I am looking for. The most complicated part for me is to figure out if and how I can dim the lamp, since I do not know how to do that.
This is an example for the lamp I might buy. The power specs for this lamp seem to be input 100–240 V ~ 50/60 Hz, and the output is 12 V DC, 650 mA. It seems to me that the power supply is external, i.e. it has a externally available 12 V DC input, but I don't know that. If it's possible to work with the 230 V input that would be best.
How can I dim the LED lamp in a programmed way? What do you suggest to control the dimmer as an alarm clock?