Voltage
Electric potential, also called as electric potential difference, electric pressure tension, is the difference in electric potential between two points.
For LED Pkg, the voltage is 3Vdc(Normally, from 2.8V to 3.2Vdc), which means the Chip inside the LED Pkg is 3Vdc.
In Low voltage DC LED strip lights, most of them are 12V and 24Vdc. However, there are some LED strip lights in 5Vdc and 48Vdc.
In High voltage AC LED strip lights, they are 110Vac and 220Vac.
LED Package
3Vdc
LED strip Lights
12/24Vdc
COB Strip Lights
110/220VAC
Watts
Electric Power, is the rate of doing work(electrical energy transferred by an electric circuit), measured in watts, and represented by the Leter P, the unit is Watt, one J(joule) per second. The watts are customizable for LED strip lights.
FOr LED Pkg, the watts maybe 0.2W or 0.5W:
SMD 2835, 3Vdc, 60mA, 3Vdc x 60mA = 0.18W≈0.2W.
SMD 2835, 3Vdc, 150mA, 3Vdc x 150mA = 0.45W≈0.5W.
For Low voltage DC and High voltage AC strip lights, the power is measured in watts/meter, like:
SMD 2835, 60LEDs/m, 12Vdc, 4.8W/m
COB, 320Chips/m, 12Vdc, 8W/m
Optical Parameters
Color
Color Temperature(Kelvin, K)
Kelvin, degree Kelvin, is the Standard International unit of thermodynamic temperature.
Color Temperature of a light source is the temperature of an ideal black-body radiator that radiates light of a color comparable to that of the light source.
The Kelvin is used to describe the white color, from warm to cold, the Kelvin rising. The common Color Temperature as following:
2700K/3000K/4000K/5000K/6500K
Color(Spectrum, nm)
White color is a mixed color, it including many colors, like Red, Green, Blue, Purple, Orange and Pink etc.
In LED lighting, the wavelength is used to specify the colors. Like:
Red: around 630/660nm
Green: around 520nm
Blue: around 460nm
However, Color Name(R/G/B/etc) is used normally during communication.
Color Quality
Color Rendering Index(CRI/Ra)
Color Rendering Index(CRI/Ra), used to describe how close between the light source and sunlight.
If the quality of the sunlight is 100, the LED light source could be as following:
Ra70+: poor quality
Ra80+: normal
Ra90+: good
Ra95+: superb
To learn about the difference between CRI and Ra, please read:
What is the difference between CRI and Ra?
Color Consistency(SDCM)
SDCM used to describe how close between the light source and Stardard (ANSI and ErP etc).
ANSI or ErP issued standards on regular Color Temps, like 2700K/3000K/ 4000K/5000K/6500K, they can be marked in CIE 1931, so as the Color Temps of LED light source, the distance between them as the SDCM:
SDCM>6: not good
3
For more details, please read: What is the difference between ANSI and ErP standard on Color Temperature?
Brigtness(Luminous flux)
In photometry, luminous flux or luminous power is the measure of the perceived power of the light. The Standard International unit of luminous flux is the lumen(lm). One lumen is defined as the luminous flux of light produced by a light source that emits one candela of luminous intensity over a solid angle of one steradian.
Lumen is used to describe how strong a light in LED strip lights, the Lumens of LED strip lights are quite different due to there are thousands of LED strip lights. The lumen may vary from below 300Lm/m to above 6000Lm/m. There are some typical Lumen for reference:
SMD 2835, 60LEDs/m, 4.8W/m, 450Lm/m
SMD 2835, 120LEDs/m, 9.6W/m, 900Lm/m
COB, 320Chips/m, 8W/m, 800Lm/m
COB, 528Chips/m, 15W/m, 1800Lm/m
Light Efficiency(Lumen/watt)
Light/Luminous efficacy is a measure of how well a light source produces visible light. It is the ratio of luminous flux to power, measured in lumens per watt in the International System of Units (SI).
The light efficiency use to describe the transfer rate from electricity to light, the higher the better, however the cost of the LED strip lights would be higher too. There are some typical lighting efficiency for reference:
SMD 2835 LED strip lights, 22-24Lm/LED, 6 LEDs/Cut, 95Lm/W
SMD 2835 LED strip lights, 22-24Lm/LED, 7 LEDs/Cut, 110Lm/W
SMD 2835 LED strip lights, 22-24Lm/LED, 8 LEDs/Cut, 127Lm/W
However, when using 33-36Lm LED Pkg, the efficiency could reach 200Lm/W.
For COB strip lights, currently the max efficiency is 135Lm/W. Typical efficiency is 100Lm/W.