Dawn and Dusk 110V CFL/LED dimmer

Projects General Guidance
1

Hi,

I've been itching to use an arduino for a while and finally have a home project it may help with!

Project Goal:
To allow a dawn and dusk fade on a 110V LED lamp over a fish tank.

Functional Requirements:
The controller will dim a string of 10 12W GU10 LED's over the course of a 3 hour period
The control point must be the AC input to the lamp
There will be minimal visual flickering
On and off times will also be determined based on a 24 hour clock

Budget:
$75

I've looked into this and it seems like there are some expensive modular solutions, and many solutions that will work with incandescent lights but not LEDs or CFLs. I'd like to keep it cheap and simple (of course, hah).

Thoughts:

  1. Servo motor + Rotary Dimmer. Downside - relies on mechanical devices. Upside - conceptually simple
  2. Pirate an infra red dimmer's control signal. Downside - Huge variance between dimmers, would like some proof of concept before trying. Interference / exterior light may cause inconsistent operation. Upside - can be controlled remotely.
  3. DIY Triac circuit. Downside - more work parts etc. Upside - Clean solution.

Thank you very much for any help you guys can provide,
Rob

2

What troubles me about the preferred solution (the Triac) is not knowing what is in the AC module. If it relies on AC power to generate its own circuitry it might simply fail at a certain point rather than dim. Can you give more details about what this thing is, that plugs into the power point, and drives the LEDs?