NLED Project Design Guide - Strip LEDs
Strip LEDs, 12 volt or 24 volt:
The most important part of a LED project, the LED didoes.
12 or 24 Volt LED Strips: The most commonly available and utilized type of LEDs. They are available in numerous configurations, colors, strip substrates, densities, and lengths. Strips are typically 1cm wide and come in lengths up to 5 meters. They come in single colors, RGB, RGBW with different packages of LEDs, but 5050 is the most common size.
LED Package: The 5050 is the most common, and will usually contain 3 LED diodes. For an RGB type, there is 1 diode per color. For a white LED in the 5050 package it will typically contain 3 white diodes, and can be considered 3 times as bright as compared to a single color of a RGB version. There are many other packages available, such as RGBW in a 5050, but also smaller ones like the 3528 is common. All the different package sizes can essentially produce the same amount of light per diode. A single red 3528 produces the same amount of light as the red of a 5050 RGB. Changing the density of the LEDs alters the maximum light output.
https://www.flexfireleds.com/pages/Comparison-between-3528-LEDs-and-5050-LEDs.html
LED Density: Specified in LEDs per meter. 30/Meter, 60/M, 90/M. Increasing the density increases the light output and current consumption.
Current Regulation: LED strips always have onboard current regulation in the form of resistors. Each section of LED strip has a set of resistors, one for each color. The resistor values chosen vary between manufacturers, and are chosen to fine tune the output colors, though some may use the same resistor values for every color.
Voltage Drop: A significant problem when using LED strip, covered more in the “Power Wiring” section. The strips can only carry so much current before the voltage starts to drop, usually in the areas furthest from the power supply. This causes color inconsistencies between LEDs. It is best to evaluate the project, but expect to inject power every 3-5 meters for best results.