1, What is the difference between the 5050 SMD LED and the 3528 SMD LED Mainly represents specifications outline dimensions: 35mm*28mm, 50mm*50mm size is not the same, the power is not the same, in SMD 3528 application, whether in brightness or in life are not advantages compare with SMD 5050, size is not the same. 2, What are these use for the 3528 and 5050 SMD LEDSMD 3528 and SMD 5050, is surface encapsulation size of SMD. Using the package dimensions as name. Compare with The DIP lamp ,the lamp brightness of Surface mount type SMD lamp is low , but compared other, convenient repair, angle is bigger. So the general almost use the SMD chip LED in indoor LED display screen　 3, LED soft lamp strip 50505050 is the LED package types. The package dimensions as Name (SMD5050). Refers to the 5050 type LED lamp.
4, what does mean about compatible with piranha 02.03.04? How are SMD? What is big power?
Piranha is composed of a SMD chip, 02.03.04 is LED the type of the bracket. SMD=”Surface Mounted Devices”, meaning: surface mount device SMD is a unified model of product. For example: TOP, Chip, can become a SMD, is also belong to the flat package.SMD chip is a bit vague, encapsulated with 5050 or 3528 SMD chip to do the piranha.
Of course, there are many kinds of the chip size. Used to do the SMD size ranging from 7 * 9mil–24 * 10mil.High power: voltage is more than 0.5W, can call the big power.
Basic knowledge of LED Testing Technology
The forward voltage: through the forward current of light emitting diode in order to determine the value, the voltage drop generated in the polarization .

Reverse current: in order to determine the value of the reverse voltage across the light-emitting diode (when the current flowing through the light emitting diode).

The peak wavelength: power maximum of spectral radiant.

Half intensity angle: the luminous (or radiant) intensity distribution, luminous (or radiant) luminous intensity is greater than or equal to the maximum intensity constituted half angle.The dominant wavelength: any color can be looked at as a spectral color, according to a certain proportion and a reference light source (such as the CIE standard light source A, B, C, etc. can source E standard illuminant D65) phase mixing and matching color coming out, the main wavelength of the spectral color is the color. Dominant wavelength is equivalent to the human eye observation to color palette (mental capacity). If you have obtained the chromaticity coordinate measured LED device, can use to white E light source (x0=0.3333, y0=0.3333) as a reference to calculate the main wavelength and determines the color of the light source. Calculation based on a chromaticity diagram connection reference slope straight line light source color point and the sample color chroma point of intersection line, look-up table read and spectral locus, determine the main wavelength.

The average intensity of light source: ratio of units in a given direction on a solid angle element is contained within a small flux D Phi V and the solid angle of D Candela (CD)

Radiation bandwidth: spectral radiant power is greater than or equal to the maximum value of half the wavelength interval