solar powered led street light and Reliability

'Reliability' is a noun, a time when the spindle means that the equipment specified, limited period, the probability of the normal operation of equipment. Reliability of the concept has been applied in the electronic product design and R & D stage, its purpose is nothing more than to be able to meet the expected to the quality of their own product design and meet the needs of the users.

Of course, because between 2008 and 2009 global financial tsunami, the economic situation into a rare low tide, the 'carbon reduction' has become the world's only slogans and common goal, so the LED (light emitting diode - Light- Emitting Diode) and therefore become a 'save energy and reduce carbon' era of the product. As long as it is involved with the 'light' products on the relationship between the various manufacturers had no no attempt LED lights intercropping link. Such as: lights, lighting, indoor atmosphere lights, billboard lights, lights, panel backlight ... and so on, in the past two years, rapid development, and even the speed of development of these LED-related peripheral products is much larger than the international standard unit related to the development of LED testing regulations, resulting in the world, no one put universally applicable code of laws for LED related products used by the designers, the LED regulations on the market into a hundred schools of thought contend, respective interpretations of the Warring States.

So I see this situation, and judged the results ina short period of time should not have to reach a consensus, and thus would like to provide some recommendations for the majority of the LED product designers, the objective is not to call people to the regulations of LEDs to birth, but to share their personal experience in the reliability of the field to outline that there were no precedents or international standard methods under the guidance of origin as a product designer, how LED products designed to do preliminary and basic authentication Understanding developed by the tolerance of LED products, thereby enhancing their quality of design standards to improve market acceptance, as well as reduce the risk of customer back.

The following briefly describes the two major parts, regardless of the LED is showing the way of parts or finished products, can use and follow the following pattern to achieve the basic validation of the LED products.

(1) product life verification
In the electronics industry, the requirements of the products of life, usually using the three methods

(1) life prediction method (Prediction)
Methods: The principle of the counting method (Part count) and the parts stress method (Part stress) according to MIL HDBK 217 parts, the use of software to calculate the life of the product.
Advantages: short time-consuming, low cost
Disadvantages: the results with the actual product life far different

(2) lifetime measurement method (Demonstration)
Methods: Using the acceleration model (Acceleration model), calculate the acceleration factor (Acceleration factor) and the actual sample to the use of environmental test simulator samples measured in order to achieve the life of the product. Acceleration model to the Arrhenius model (high temperature accelerated), the Coffin-Manson, model (temperature cycle acceleration) and Hallberg,-Peck, (humidity accelerate) with the highest degree.
Advantages: compared with the results of estimation used real, industry-accepted high
Disadvantages: higher cost and time-consuming than the forecast method

(3) market feedback method (Field return)
Method: the user of recycled products used in the market situation.
Advantages: the result is equal to real life
Disadvantages: time and cost of longer market the use of difficult to obtain, usually only the brand field of self-preservation
The above three methods to obtain the product life life measured up to the industry using, because it will not only exempt from the results actually produced the gap is too big drawback, and it is derived through the measured, regardless of the buyer and the seller acceptance are high.

Environmental testing verification
I have proposed in the March issue of component magazine in 2009 on the definition of environmental testing of the LED-related products need to execute projects and these projects is simple. Therefore, in this test and details not to dwell. But this should be guided how to use these environmental pilot project has reached really improve the quality standards of product design.

Must first do the analysis of the contours of a life for their design of products, the existing environment of the product life cycle may be at? User why? The properties of this product? Are there other special requirements? These factors are likely to affect the future specifications of the test, not to fall into the norms of lost in the process, verify the specifications is by no means completely from a specification completely copied into a good, because no matter how good the specification can not simulate the actual environmental needs that are only futile, it will only waste more resources and cost. For example: LED lamp designers to design a street lamp to street use in Indonesia, and verify specifications and to develop low temperature of -40 ℃, very happy to do so, as proposed in the IEC where low temperature is -40 ℃. But please recall that Indonesia is located near the equator, a tropical climate, hot and humid throughout the year, how can encounter -40 ℃ climate? Therefore, never touch the environment to do product design, will only increase the design costs because the design can withstand -40 ℃ environment LED lamps cost is higher than the design enough to withstand the environment of 0 ℃.