The nominal voltage of lamp
The nominal voltage of lamp has a big significance, All of these lamp products have a detailed datasheet. These file all refer to a nominal voltage to indicate that lamp work voltage. the lamp will be damaged if It’s over nominal voltage. we can through the common lamp to be clear about the importance of nominal voltage.
1、Incandescent lamp
for the development of luminescent materials
the tungsten filament as a electroluminescent material .This format does have some drawbacks, however, such AS the tungsten filament which can be burn off at high voltage and big work current.
2、Fluorescent lamp
The work voltage which is more than that in effort can cause severe damage of fluorescent lamp starters. right now in status, the fluorescent lamp was break.
3、LED
The voltage and electric current of LED not exceeding specified limits. the LED structure may be impacted.

Reasons for frequent failure of LED
LED is freeze-sensitive electronic components. 20mA was the maximum value for LED work electronic current . likely to cause the LED failure in the process of using., If the steps are not followed, in some cases the led may not work. This paper analyzes the causations of LED damage,
1, The electricity supply short-circuited has been a sudden rise.
2, Then the slope rises ever more steeply as other device temperature, until it reaches an damage point.
3. There’s a short circuit somewhere in the circuit , caused these current to enhance,
4. The PCB board is taking in water, Water pipes conduct electricity.
5. The missionary hadn’t been wear antistatic clothing and shoes when assemble the led. The operation failed due to led internal damage.

The causes of failure and protection measures taken in the design, fabrication and operation of LED tank were discussed for next article.

CRI( Rendering Index) and color temperature
We studied the theory of CRI and color temperature of LED in my previous articles. but Many asked me to say that Understand correctly both relations .This article examines the relationship simply.

 CRI( Rendering Index) and color temperature  in test report

The popular understanding of the color temperature that the color at the yellow or in the blue The popular understanding of CRI is light object to the target image color range . Of course, the two are not entirely related. But for the Cree is concerned(high CRI are generally low color temperature),we copied the relevant data out of the datasheet.

Notes:
• Cree maintains a tolerance of ±7% on flux and power measurements, ±0.005 on chromaticity (CCx, CCy)
measurements and ±2 on CRI measurements. See the Measurements section (page 10).
• Typical CRI for Cool White (5000 K – 8300 K CCT) is 70.
• Typical CRI for Neutral White (3700 K – 5300 K CCT) is 75.
• Typical CRI for Outdoor White (4000 K – 5300 K CCT) is 70.
• Typical CRI for Warm White (2600 K – 3700 K CCT) is 80.
• Minimum CRI for 80-CRI White is 80.
• Minimum CRI for 85-CRI White is 85.
• Minimum CRI for 90-CRI White is 90.
• Flux values @ 25 °C are calculated and for reference only.
** Calculated flux values at 700 mA, 1 A and 1.5 A are for reference only.

led power and led Illumination
We are covered the theory of led power and led Illumination . As for these theory , But many of our users don’t think that’s enough. today we has done experiments complementary to those of theory , please see the table as follows;

Light intensity of LED
Unit of LED light intensity is lux. Lux (Illuminance) is a measurement of the light intensity at any point. It is equal to 1 Lumen per square meter. Light intensity is calculated for each surface/ polygon. The physics concepts of LED light intensity can not be divorced from its laws. it will beneficial to organisms ‘photosynthesis . we can measure is the light intensity by illuminometer .

Spectrum characteristics of white LED

The white LED is composed of a blue LED chip(( In. Ga) N) and a color conversion layer of YAG: Ce3+ phosphors dispersed in a medium such as epoxy resin. other words it mainly assembled by a blue and yellow. Please see Spectrum characteristics photo of white LED as follows;

The wither LED create light of the spectral curve. is indicated by a solid line . View the first wavelength of the peak of the spectral curve. be matched dollar-for-dollar with 460nm，and the blue and their corresponding relationship . the secondly wavelength of the peak of the spectral curve. be matched dollar-for-dollar with 580nm，the 580nm corresponding to the yellow. As you see (white LED), there are two elements: 460nm(blue) and 580nm (yellow) . This would be considered an white . light susceptibility of curve is indicated by a dotted line

Lens with the transmission rate
The transmission rate is physical verbs. it represents that the efficiency of transmission rate in display device.
The main products are all kinds of material: creamy white PC, stripes PC, transparency PC, creamy white glass cover . and they have different the transmission rate.
Type                                                Transmission Rate
creamy white PC                          80－85％
stripes PC                                        85％
transparency PC                        90－92％
creamy white glass cover      90% above

lighting principle of LED
First we know what light are different ways of changing energy from one form into another. this photoelectric transformation is implemented by diode. that happens when two atomic nuclei collide with each other, releasing energy in the form of photons. i picked on simple work to illustrate these LED principles.

LED–Light Emitting Diode, it is Semi-conductor electronic components that can lighting, and LED is a current injected device whose characteristic and life are greatly dependent on the performance of LED-used current supply. the recombination of photogenerated holes and electrons to radiating copious amounts of light when led is also observed under forward voltages .

Restraining the complex of the electrons and cavities on the reversal voltage .

And we’re talking about numbers of release energy, because it is the fundamental condition that light wavelength .(From a physical standpoint, there ought to be as many colours as there are different wave lengths)。
Calculating formula of wavelength：

LED current

The current of normal led as 10~20MA, other kind led solutions Which Adopts Low-current LED(the threshold current ranges from 1.5~2mA)
In addition to, we also measure the other color led current, as follows,

RED led voltage: 1.82-1.88V     RED led current: 5-8mA，
Green led voltage: 1.75-1.82V     Green led current: 3-5mA，
Orange led voltage: 1.7-1.8V     Orange led current: 3-5mA  ，
Orchid led voltage: 3.1-3.3V       Orange led current: 8-10mA ，
White led voltage: 3.1-3.3V       White led current: 8-10mA ，

Does this LED want install a ground cable?
If bulb has ground line ,please note that the ground line should also be connected in the lamp .because we are make sure the machine is earthed properly, Proper grounding is required. Periodically check the insulation of every electrical components to prevent possible electric shock and injuries.In generally the user should see two lines on the lamp. :neutral wire and live wire respectively! Along with this lamp. normally ,the high-power led would have connected ground cable through External rectifier(the work voltage of External rectifier is alternating current, the External rectifier with its own ground cable ). when the overloaded security protection.