48" LED Array - Up and Running...Mostly

[Ron99]

Originally Posted by hillegom

How many amps at 12V do you need?

Only a couple of amps. The Arduino itself uses very little current, it dependes on what is plugged into it. I will probably only be using it to generate the PWM signal and power a real time clock circuit so it will likely only be using a few hundred milliamps at most. the three fans will probably use more and fans typically draw around 300mA; maybe a little more. So a 2A power supply will likely be more than enough.

Originally Posted by StirCrazy

um, thats stupid, I figured the PWM models would be based on 5V as there is only need for a pulsed signal not a voltage.. oh well.

Steve

Yeah, but I guess they did not design it with microcontrollers in mind. You can apparently use lower voltage but it will not go to full brightness. I am using a 9V battery for test purposes just to get it to fire up. It lights but is probably not a full brightness. It is basically using a 10V signal for full bright that is then chopped up for the dimming.

Originally Posted by StirCrazy

Ron, what about using a 10V power supply to power the arduino, and then taking the power from your 9V out wich will actualy be 10V. this will eliminate that need of another power supply as I can't imagin you need much of any current for the PWM.

Steve

You are correct. I am still figuring out the Arduino and assumed it needed 5V in but it can take 12V in as it has it's own voltage regulator on board. So I can use a single 12V supply for the fans, the Arduino and then with a voltage regulator to supply the PWM. I don't see a 9V out on the Arduino, just a 3.3V and 5V outputs.