2012-10-16

High quality LED lamp

LED manufacturers and their distribution partners are working hard to improve product flux tolerance, at reasonable cost range to provide finer classification. For hope that the product can use 5 or 50000 hours, and in the use of period to maintain overall light output constant designers, even want to meet the most intensive flux classification and set the tolerance of 0.1% current source is also very difficult to achieve. Because the heat and over time and the attenuation performance of two important factors may reduce LED luminous flux, Viribright LED globe lamp dab8d29ck even if the current source tolerance and LED flux tolerance to achieve 0.001% can not solve the problem. To account for these losses, high quality solid-state lighting products designer must find additional feedback loop power, namely, find the heat and light. This requires the dimming control, the output current of the linear control and PWM ( pulse width modulation ) control IC has become the best choice.

The United States National Semiconductor LM3409 and LM3424 is a LED drive IC control, which is applicable to the semiconductor lighting second generation current source. Two products can be through the variable resistor or a voltage source to control the average LED value of current, and can provide PMW (pulse width modulation ) modulation optical signals to provide specialized input signal. In addition to the linear control circuit, LM3409 and LM3424 analogy regulation function also allows a system designer can weigh in the output current accuracy and the size, cost and current detecting resistor between the power to make their own choices.

Need a light control application

Street is a very good source examples, because it has a strict legal standard limit. The road lamp, EU countries set the minimum and maximum light output and lighting model. To conform therewith and provides five year or longer service life of LED lamps, the design must take into account the heat caused by the instant flux loss and longer time to bring down flux loss performance. A natural approach is to use light sensors, such as constituting a linear control circuit of photoelectric diode. The system is enabled on the first day, Viribright LED Bulb Brand shall use only a portion of the overall drive current, this is done by taking into account with the passage of time, the drive current will be increased to a cap, thereby ensuring constant light output. The photodiode bias, and converted to a pulse width modulation signal, which will help in the dimming range of maintain a more constant relative to the color temperature, the linear control circuit is more simple, generally dimming range is relatively small. According to the different time, motion sensors or other measures of saving power consumption, light output control, the PWM control will be more useful. Figure 6 gives a longer life, constant light output LED lamp putative principle diagram.

Output current accuracy evaluation of LED drive only one aspect of performance, but when LED itself flux tolerance remain at far higher than±1% level, even if the current source tolerance and several instruments processor voltage rail tolerance requirements as strict, almost without any meaning, the average LED current tolerance should be about to luminous flux tolerance. In this paper, based on a single classification error of an ideal situation, and gives some practical examples, the examples of the use of two or more classes of LED, its tolerance can also more easily reach± 5%,± 10% or higher. In additional to the control loop, should make money for 1% of the current control, and power in higher detection voltage can be. Some LED exhibit of lanterns emphasizes more simple and practical and low cost, and even using a linear light would be too complex and expensive, but if you want to play LED full performance lighting requires the use of linear control or PWM ( pulse width modulation control ) mode or the two coordination use, hkcar and upgrade the product performance and service life.

2012-07-05

light rate encapsulation structure

High take light rate encapsulation structure and technology

In use process LED, radiation from the photon in composite to launch the generation when loss, mainly includes three aspects: chip internal structure defects and material absorption; In a photonic forms face because of losses caused by refractive index difference reflection; And the greater than the total reflection LinJieJiao Angle and cause of total reflection losses.online ups power manufacturer So, a lot of light can't from chip shots to the external. Through the chip surface coating a layer of refractive index relatively high transparent cover (pouring sealant was), because the fillet in chips and air between, thus effectively reduce the photons in the interface of the loss, improve the efficiency of take light.

High power white LED encapsulation structure

In addition, the role of the pouring sealant was also including the chips for mechanical protection, stress release, and as a kind of optical structure. So, ask its light transmittance high, high refractive index, and thermal stability, good fluidity and easy to spray. In order to improve the LED package reliability, also requires pouring sealant was with low hygroscopic, low stress, ageing resistance and other properties. Now commonly used pouring sealant was including epoxy resin and silica gel. Because of the high silica gel transmittance, refractive index, heat stability, and stress is small, hygroscopicity low characteristic, is obviously superior to epoxy resin, in high power LED packages to be widely applied, but cost is higher. Research shows that increasing the refractive index can effectively reduce the refractive index of silica gel physical barriers brought the photon loss, improve the quantum efficiency, but by environmental temperature on the performance of silica gel is larger. As the temperature increases,LED Products dab4d56ck the thermal stress of silica gel internal increased, leading to lower the refractive index of silica gel, which affect LED efficacy and light intensity distribution.

The role of light color phosphor in compound, form white light. Its main characteristics including grain size, shape, the luminous efficiency, conversion efficiency, stability (heat and chemical), among them, the luminous efficiency and conversion efficiency is the key. Research shows that, with the temperature rises, phosphor quantum low efficiency, reduce the light, radiation wavelengths will also be changing, and cause a white LED colour temperature, the change of the color and the higher temperature will accelerate the aging of phosphor. Reason is that the phosphor coating is by epoxy or silica gel and phosphor deployment and become, the cooling performance is poorer, when moving or by ultraviolet radiation, vulnerable to temperature sudden destroyed and aging, the luminous efficiency to reduce. In addition, high temperature and potting glue of phosphor thermal stability problems. Due to the commonly used in 1 um above phosphor size, refractive index is equal to or greater than 1.85, and silica gel refractive index generally in 1.5 or so. Because do not match between the refractive index, phosphor and particle size light scattering far limit (30 nm), so the phosphor particle surface exist light scattering, reduce the light efficiency. Through adding in silica gel nano phosphor, can make the refractive index increased to 1.8 above, reduce light scattering, improve the efficiency of LED light (10% 20%), and can effectively improve the quality of light color.

The traditional phosphor coating way is to phosphor and pouring sealant was mixed, then click coated in the chip. Due to the lack of phosphor coating thickness of the shape and precise control, causes a shoot the light color not consistent, appear blue or partial partial wall. And Lumileds company developed the form coating (Conformal coating) technology can realize the phosphor uniform coating, safeguard the uniformity of the light color, as shown in figure 3 (b). But research shows that, when phosphor coating directly in chip surface, caused by the scattering of existence, a light low efficiency. In view of this, the United States Rensselaer institute presents a Photon scattering Extraction process (Scattered Photon Extraction method, SPE), through in the chip surface decorate a lens,LED PAR Light and will contain phosphor glass from the chip must be placed in position, not only improve components reliability, and greatly improve the efficacy (60%),

2012-06-27

lens wear up to 40 years

Contact lens wear up to 40 years
Contact lenses since invented, by the broad masses of the favorite in myopia patients. Although it is beautiful, but not for everyone.coriolus versicolor 15 years ago, people over the age of 40should not wear contact lenses.

Primary and middle school students are in the growth stage, eye axis has not finalize the design, if premature wear contact lenses, easy to produce corneal hypoxia and physiological metabolic disorders. If the lens diameter and corneal inconsistent, can cause corneal abrasion, severe cases can lead to corneal ulceration or perforation. Therefore, unless there is a special need,LED Lighting manufacturer dab4d55ck primary and secondary school students the best wear frame glasses.

After the person arrived 40 years old, ocular tissue will happen more pronounced degenerative changes, ocular tolerance to hypoxia reduced capacity, in this case on the eyeball surface wearing layer of lens, will cause the eyeball hypoxia, thereby inducing corneal infection, ulcers and other complications. Therefore, the people over the age of 40is best not to wear contact lenses.

Young man wearing contact lenses, as soon as you feel the eyes of a foreign body feeling, dry, hyperaemia, secretions, burning and other abnormalities, should immediately stop wear, and to the hospital.baby wholesale clothing Other not to wear contact lenses case also includes: the eyelid, conjunctiva, corneal inflammation, trachoma, dacryocystitis.

2012-06-19

times seem a bewildering

For boaters seeking to switch to LEDs, the aftermarket can at times seem a bewildering mish mash of unknown brands and confusing options.overseastudyhk.com/ With the huge popularity of marine LEDs has also come a large number of new distributors and suppliers, each seeking to gather his share of the market, and portion of the boaters funds.

Unfortunately, this has also led to a lot of unhappy boaters as they seek to purchase the cheapest LED fixtures possible without understanding some of the problems associated with bargain brand LEDs. While generally speaking LEDs outperform incandescent lights by a wide margin in almost every measure of performance, they still require some extra attention to detail that is often lacking in bargain brand versions. To avoid some of the problems, boaters need to understand a few salient points before embarking on their venture into LED lighting.

First and foremost, boaters need to understand that when it comes to LEDs, you do indeed get what you pay for.ipazzport dab4d53ck While those bargain LED spreader lights from China may look like a great deal, there is a high probability that they were manufactured with cheaper materials of an unknown quality.

The internal electronics may not have the needed extra attention to detail or durability that the marine environment demands as well, with thinner gaskets, lower grade circuitry, and cheaper metals and alloys used in their construction. While these lights may indeed work, and even look good once installed, it's a guessing game as to how long they will last, and there is a strong chance that should something go wrong, customer service may not be quite the pleasant experience one would hope for.

To avoid some of the uncertainty, the safest route to follow is the one paved with known brands and established manufacturers of marine lighting equipment. While it is true that many new startups and foreign brands may eventually develop a solid reputation for quality and service, as a cost conscious boater the wisest choice is to go with established companies that have the resources available to allow them to use only quality materials and designs and provide effective service when needed.

Look for names like Cree when purchasing LEDs as these indicate that a known and reputable design of LED is included in the fixture. Consider exterior lighting fixtures with IP ratings of IP65 or higher as this indicates the fixture can withstand the wet and corrosive marine environment well.LED Floodlight Utilize stainless steel mounting hardware and waterproof connectors when installing the lights to give them the longest possible lease on operational life.

Avoid LED fixtures with plastic housings and lenses if possible, and look for designs that use aluminum for housings and LEXAN for lenses as these offer the highest durability possible

2012-06-12

interior lighting popularity

LED light to the interior lighting popularity
" Sichuan Chengdu and LED industry raw material, the substrate wafer, LED chip, fluorescence powder, device package and application products, have a certain advantage, only in Chengdu and Mianyang, A19 LED Light Bulb dab4d52ck a gathering of more than 30enterprises engaged in the development and application of LED, LED related product sales income over2000000000 yuan."

Yesterday, the Municipal Science and Technology Bureau relevant responsible person told the reporter, in Chengdu, to Tung Chun, Sony source industry chain enterprises have already in LED sapphire epitaxial wafers production, rare earth fluorescent powder package and driving circuit design, with independent intellectual property rights of international competitiveness, and white LED lighting applications engineering involves the content of new and high technology new materials and new products, its industrial radiation pulling power will drive whole town LED chips, metal materials, machining, electronic components, transportation and many other industries development.

It is understood, in our city" eleven five" science and technology development planning of major projects," semiconductor lighting materials industrialization key technology research" has become one of key tasks, and has organized the implementation of the" high brightness white LED lighting demonstration project"," discrete user / municipal engineering of solar LED lighting system integration model" project, accumulative total extends more than 1000 lamps LED street lamps, tunnel lights, and in the pilot in the completion of the LED light source and the solar energy system integration integration technology research and design.

In accordance with the pilot overall goal, I will be in the pilot, LED lighting pilot demonstrative job, popularization and application of LED street lamp 10000above, tunnel lamp5000lamp lighting from above,ipazzport bluetooth keyboard LED road lighting into the industrial and mining enterprises and general interior lighting, Chengdu LED industry leading technology level, talent aggregation ability, product application scale will be maximum lift.