I want to use 5 meters 5050 RGB Waterproof 300 LED Strip + 20 Key Music IR Remote Controller Sensor. Is it okay if I use a 12V 6A Power Supply?
The manufacturer or supplier should specify current per length of strip.
As a "rule of thumb" most small LEDs are rated at 20 mA and groups of 3 are connected in series plus a series resistor to 12V. So approximately power dissipation for N LEDs =
Power = V x I = 12V x 20 mA x N/3 = 80 x N mW.
And I = 20 mA x N/3
For N = 300
Power = 80 x 300 mW = 24 Watts
& I = 20 mA x N/3 = 20 x 100 mA = 2A.
The two answers differ.
I think this one is correct :-).
I'll check the ratings of some 5050 LEDs but I think the other answer may not have allowed for the 3 LEDs per package.
The datasheet of 5050 LEDs says forward current is 60mA at 3.6VDC.
60mA * 300 pcs = 18000mA or 18A at 3.6VDC.
In addition you must calculate wasted power in resistors and in wiring of the strip. It's hard to say how much power it uses without knowing what kind of LED strip it is, and how it's designed.Does it have input voltage of 12V? Or do you have to bring the voltage down?