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Showing posts from June, 2020

LED Lamps Aging and Life Test

Many customers need aging LED lamps, but do not have a clear concept of aging test and life test. Aging test usually use aging test racks. What is aging test rack? Aging rack is dedicated to simulate the products in real conditions involved in the use of various factors on the aging of the product conditions to strengthen the process of the corresponding conditions. Why we need aging test? Electronic products, no matter components, parts or machines, all need aging test. Aging and test is not one concept, aging firstly and then test. Electronic product after manufacturing forms a complete product, which is able to play its role. But users may find a variety of problems after use, most problems occurs in the first few hours to dozens of hours. Later, formulate electronic products aging and test to simulate the using state or equivalent products. This process is done by the product manufacturer. The problem products will stay in factory, products without problems will sell to users...

Surge generator: IEC 61000-4-5-2014 Surge Immunity Test

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The International Electrotechnical Commission (IEC) has published IEC 61000-4-5 :2014, “ Electromagnetic Compatibility (EMC)  – Part 4-5: Testing and Measurement Techniques –  Surge Immunity Test .” “IEC 61000-4-5:2014 relates to the immunity requirements, test methods and range of recommended test levels for equipment with regard to unidirectional surges caused by over-voltages from switching and lightning transients. Several test levels are defined which relate to different environment and installation conditions. These requirements are developed for and are applicable to electrical and electronic equipment. The object of this standard is to establish a common reference for evaluating the immunity of electrical and electronic equipment when subjected to surges.” “The test method documented describes a consistent method to assess the immunity of an equipment or system against a defined phenomenon. This standard defines a range of: test levels; test equipment; test set...

LISUN 3M Integrating Sphere Test Results Comparison with Third Party Laboratory

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Lisun engineers visited Barcelona recently, this visit was mainly to install the  3m Integrating Sphere Test System for the customer and provide training service. This customer compared the test results of Lisun’s 3m Integrating Sphere Test System with the test results of Holophane(HEL) and LIA Laboratories.  This customer provided 4 samples to the third lab. Compared with LIA Laboratories, our tolerance are controlled within 5%: HAL – LED Highbay: 4.6% VMX LED Luminarie: 2.3% Corn Lamp: 2.5% Platek – Target Medium Prioette LED Luminaries: 0.5% The test report of Platek tested by Lisun 3m Integrating Sphere Test System The test report of Platek tested by LIA Laboratories-1 The test report of Platek tested by LIA Laboratories-2 Lisun Instruments Limited was found by LISUN GROUP in 2003. LISUN quality system has been strictly certified by ISO9001:2015. As a CIE Membership, LISUN products are designed based on CIE, IEC and other international or n...

Can we use LMS-6000 portable CCD spectroradiometer to test luminous flux lumen?

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With the rapid development of LED lighting market, the competition becomes more and more intense. So more and more LED lighting manufacturers began to focus on the quality of their products in order to gain a greater share in the market. Thus, LED lighting test instruments became the indispensable equipment.  On the LED test equipment, there are  goniophotometer ,  integrating sphere ,  spectroradiometer ,  LED driver power tester ,  EMI & EMC test equipment , and  IP waterproof ,  dustproof environmental test chamber  and so on. And goniophotometer, integrating sphere and spectroradiometer is the most common and also basic equipment, mainly used to test the LED luminaires photometric, colorimetric and electrical performance, such as lumen (luminous flux), luminous intensity distribution, luminous efficiency, correlated color temperature, color rendering index, voltage, power and other basic parameters. However,...

How to predict and test the life of LED?

In general, LED can be used for more than 50000 hours, and some manufacturers are promoting their LED to operate for about 100000 hours. The main problem in this area is that LED is not simply no longer operational.  Its rated service life can not be calculated by traditional lamps and lanterns. In fact, when testing the life of LED, no one will be waiting for it to stop functioning. However, there are other ways to measure the life of LED. The reason why LED is durable is that it does not produce filament fuses. LED will not stop operation directly, but it will gradually deteriorate over time. It is predicted that high quality LED can maintain more than 60% of the initial lamp brightness after 50000 hours of continuous operation. Assuming that LED has reached its rated service life, it may still be luminous, but the light is very weak. Without considering the power and driving failures, the life span of LED is characterized by its decay, that is, the longer the time is, the more...

Equivalent Test Between Normal & High Frequency Fluorescent Lamp and LED Tube

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Comparing with traditional fluorescent lamp, the LED tube have high light effects, low power consume, long life time and stable luminous efficiency advantages etc. At the same time, for the LED tube performance testing is became more simple, in recent years more and more customers has chosen the LED tube to replace fluorescent lamp. Due to the main lighting products are consist of traditional fluorescent lamp, like the CFL and fluorescent lamp are still occupy a large part of market, it’s impossible to replace all of them immediately, specially at the business centre and market still have many fluorescent lamps and compacted lighting products; if replace all fluorescent lamp to LED tube, it’s need lots of tome and huge cost, the most important is this way can’t be approved. In order to make replacement work more effective, the IEC issued the IEC 62776 standard dated December of 2014, this standard explain how to do equivalent test between normal & high frequency fluorescent lamp...

LED packaging principle

LED package is mainly to provide a platform for LED chips, so that LED chips have better performance of light, electricity and heat. Good packaging can make LEDs have better luminous efficiency and good heat dissipation environment, and good heat dissipation environment can enhance LEDs. The service life. LED packaging technology is mainly built on five main considerations, namely optical extraction efficiency, thermal resistance, power dissipation, reliability and cost performance (Lm/$). There are many kinds of LED chip packages, and different styles of packages should be used according to the actual photoelectric characteristics. However, the common LED packages have the following five common patterns. First, the LED chip soft package, this package style is generally used in the LED display of character display, digital display, and electric display. The soft package of the LED chip is to directly bond the LED chip on the PCB printing plate, and connect the desired characters an...

How to measure electric, photometric and colorimetric parameters for LED lamps and lanterns?

The main parameters of LED lamps and lanterns include: A: Electric parameters: voltage, current, lamp power, power factor, harmonic, etc B: Colorimetric parameters: correlated color temperature, color rendering index, chromaticity tolerance, color coordinates, SDCM, etc C: Photometric parameters: luminous flux, output luminous efficiency, beam angle, UGR table, intensity distribution, candela table, IES LDT files, etc (1) Electrical parameters are very easy to measure. Just apply one power meter to the integrating sphere system or goniophotometer system. (2) There are two methods for colorimetric parameters measurement. First, we use spectroradiometer integrating sphere system . Second, we put a spectroradiometer and color sensor in the goniophotometer darkroom. You can  measure color property parameters and also color temperature distribution according to the angle. (3) For total lumen, luminou flux measurement, there are also two methods. First, we use spectroradiometer ...

Characteristics of LISUN GDJS series High and Low Temperature Humidity Chamber

LISUN GDJS series High and Low Temperature Humidity Chamber  is according to IEC60068-2-1 ( GB/T2423.1 ) and IEC60068-2-2 ( GB/T2423.2 ). It is used to test the CFL/LED which meets  IES LM-80-08 , electricity products, electronic components, material and so on. There is some other manufacturers in China also produce High and Low Temperature Humidity Chamber, and our equipment is mainly different from the following four points: (1) Display temperature: We use Schneider or Omron’s relay. And the temperature that can be reached is the temperature under load. But many manufacturers refers to the temperature without load. If under load, the temperature must be different from the original temperature. (2) Water purification device: To generate humidity inside the equipment, there must be distilled water. And there is a water purification device in our High and Low Temperature Humidity Chamber, so we can use tap water directly, to save the cost of distilled water. But ...

Why should you choose a constant current power supply for the LED driver?

The LED is a light-emitting diode, and its characteristic curve is basically the same as that of a normal diode. When the applied voltage reaches the diode conduction voltage, the slight change of the applied voltage can cause a great change in the diode current. The constant current is used to ensure that the current in the LED is constant. No matter how the voltage changes, the current flowing through the LED does not change, which can ensure the life and light decay of the LED. If a constant voltage source with an output of 12V is used, an electric 16 ohm resistor is connected in series to supply three strings of 0.5W 5630 lamp beads. The lamp voltage is calculated according to 3.3V, the current flowing through the lamp bead Io=(12-3*3.3)/16=0.131A, and the power of a single lamp bead is P=0.131*3.3=0.4323W. Because the temperature of the lamp bead is high The voltage of a single lamp drops to 3V. At this time, the current Io=(12-3*3)/16=0.187A, the current increases by 5...

The differences of the test result between LISUN WT2080 LED power driver tester and multimeter when testing LED power driver

 Some customers suspect the accuracy of the WT2080 because there is some differences of the test result between LISUN WT2080 LED Power Driver Tester and multimeter when testing LED power driver. In fact, the test results are different because the test principle is different: the WT2080 test result is the real effective value (RMS), the multimeter test result is the average value. LISUN WT2080 is according to GB/T 24825-2009 and IEC 62384:2011 . It can measure the following parameters: Input Characteristics Test (AC/DC), Output Characteristics Test (AC/DC), Start Characteristics Test (DC) and Hormanic Test. It is specified in the standard that the test result should be RMS. The results of the general multimeter test are average values, so the test results are naturally different because of the different standards. WT2080 can print data and communicate with PC, displaying all the dates and curves in PC. There is also the average value in the test report, but on the display sc...