I'm new here, and new to trying to figure out my own little project. I've built a few electronics kits in the past, and have tinkered with a few little bits and pieces, but now I want to try something a little more advanced (for me anyway).
I'm looking to create some atmospheric lighting for my aquarium which will basically make a transition from day to night and back again. To do this i am going to install 2 rows of LEDs in the hood of my tank, a row of blue (to represent moonlight) and a row consisting of alternating red & orange LEDs, with some yellow or white at the centre (to represent the sunrise/set). I was going to do this simply by having each set of LEDs run off of an individual transformer, which is plugged into a timer. So for example:
7pm sunsets go on
8pm moon lights go on
9 pm sunsets go off
7am sunsets come on
8am moonlights go off
9am sunsets go off.
The LEDs would all be wired like this:
The resistors are all supplied with the LEDs, so will be the right values, 510 is just a guess based on other LEDs I've ordered in the past. The LEDs will be in parallel circuit so that the power it distributed evenly.
Question 1.
I had the idea of adding some additional resistors in series (or getting slightly larger resistors) for the LEDs at either end, so that the ends of the tank are slightly darker.
(Please ignore the 75 ohms in the top right, I don't know how that got there)
Would there be any issues in doing this? Would 100 ohms be too great a resistance?
Question 2.
I would like the light to fade out, preferably over 15-30 mins, rather than being a dead cut. Would a capacitor be the way to achieve this, as it would store power from when it is turned on, then as the power depletes would the LEDs dim before finally running out of juice?
If the light faded in, that would be better too, however that can happen quicker.
Question 3.
Is there any way to do this using only 1 power adapter on a timer?
Any help would be grately appreciated.
Thanks
Darren