i need some help for my masterthesis.
I plan an Light and Sound installation and for this I decided to use the shape of an Dodecahedron and I want to put LED RGB Pixel Stripes on the surfaces to light the space. Imagine it like a huge ceiling light in shape of a half Dodecahedron.
What I have:
1 x Arduino Starter Kit
4 x RGB LED Pixel Stripe: BTF-LIGHTING WS2811, 5M, 60 LEDs/m, 300LEDs RGB, DC12V
(0,3W/LED = 90W/5 M (1 LED Stripe) = 360 W/20 M (4 LED Stripes))
2 x LED Stripe: Minger SMD 2835, 5m, 300 LEDs, Dimmable, 6000K Kaltweiß, DC12V
(?)
The half of the Dodecahedron has 6 surfaces. Each surface gets like 300 to 350 cm RGB LEDs and 150 cm of Cold White.
My plan is to program the RGB LEDs with Strobe-Light (10 Hz) and changing colours and at the End of the installation the Cold White ("Daylight") is lighten up the space. (But this is another challenge for me ;))
I don't know which switching power supply I have to use?
You have worked out that your 20m of RGB strip is 360W. You need to convert that to current, because most PSU are specified by current. The formula for power is
P = V x I
where V is the voltage, in Volts, I is the current, in Amperes, and P is the power, in Watts.
Re-arranging that to get the quantity we need to know, which is the current:
I = P / V = 360 / 12 = 12A 30A
Add to that the white strip. You don't have the power rating for that, but we can estimate the current. It's normally around 20mA for every 3 LEDs. 600 LEDs would be around 600 / 3 x 20mA = 4,000mA = 4A.
So your PSU needs to supply 16A 34A minimum. For long life and safety, make that 20A 40 A. That will be able to power the Arduino also. But do not power the strips from the Vin pin on the Arduino. The Arduino board cannot handle 16A 40A, so you must take power separately to the Arduino and to the strips.
If you are not cutting the strips, you need to take separate power wires to both ends of each 5m strip. If you do not, the voltage drop along a 5m strip will cause the white LEDs to fade gradually towards the end of the strip, and in the RGB strips, they will both fade and change colour slightly, loosing the blue and becoming more pink-hued.
You are right with 40 A. I hope I can find a switching power supply. Most of them are with 30 A...
Please check my .png. (2D unfolded) to see how I plan to install the LEDs.
I just draw the RGB LED. All 5 LED stripes have to show the same programmed LED show later on.
So, I think the best way is to give every Stripe it's own connection of 12 V, right?
Yes, as long as the Arduino is not directly powering more than a handful of other components. 12V can cause Uno's regulator to overheat if it needs to power (power, not simply control) many components at 5V.
You have cited an Arduino UNO. UNOs are really for play, not for practical projects unless a particular "shield" happens to perform the whole of your requirements in one go. Otherwise a Nano is more practical, can be wired with direct soldered connections or its pins soldered on and used to mount it on a custom PCB or "breakout".
The regulator on the UNO (and Nano) is essentially not suitable for powering anything beside the microprocessor, certainly not if powered by as much as 12 V. If you plan to connect anything to the "5 V" pin (and that includes "shields"), you really should instead provide a 5 V power supply, perhaps to the USB socket (a USB "phone charger" is very practical) or a switchmode "buck" regulator module from your 12 V supply powering the "5 V" pin.
