Relationship between voltage/current & LED strips?
You are partially correct. All three: power, current, and voltage are limiting factors for your power supply. If your power supply is labeled 0-24VDC @ 5A max, then it means it can handle these max ratings:


Max Voltage: 24V
Max Current: 5A
Max Power: 120W


So you say your LED's draw 18A total. This is only half of the equation. You also need to know what voltage the strip needs to be supplied. If the voltage that the strip requires is less than 1/18 of 120 (6.67V), then congrats, your power supply can handle your LED strip. If the required strip voltage is > 6.67V, then your total power draw will be > 120W which is no good. However, you can't just willy nilly plug the LED strip into the power supply because remember, your power supply can only handle 5A. The easiest way to overcome this problem is through the use of a power transformer to turn 24V into your required voltage.







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