So, I'm designing a reef tank light controller using an Uno and a Relay Shield.
The goal is to create a dawn-dusk light cycle. The lights are LEDs, and they have a PWM controller that powers the LEDS, but needs a 0-10VDC input voltage to control the dimming level (this I would provide through programming the Arduino). I also have a set of 2 "moonlight" LEDs (total 4V required), which don't have a controller, and just need on/off control. There are also 12V fans that I need to have on when the main LEDs are running. Obviously the Arduino can't supply all that power, so I bought a Relay Shield that has 4 relays that can handle up to 30VDC each.
I already have 10V and 12V wall-warts for the existing setup (10V to provide dimmer voltage and 12V for the fans), but what I REALLY would like to do is craft a circuit which would use just one power supply that I could split the output voltage to provide the correct power to both the loads.
Does anyone have a good reference design on how to go about doing that?