Daily Archives: August 15, 2013

What‘s the next notes when designing the LED tube light

1,the  relationship among the series and parallel of the LED and PFC power factor and wide voltage:
there are three cases of the PFC power on the market,: one is a non-dedicated circuit PFC, the PFC is generally about 0.65; the other is PFC circuit with passive, the light board well matches, PFC is usually about 0.92; the other is made of 7527/6561 circuit with active, PFC can reach 0.99, but the cost of this program is twice as expensive as the second option. So the second option is more. For passive PFC circuit: which is also called valley-fill PFC circuit, the operating voltage range of AC input voltage is half of the peak. If the input is 180V, the peak is 180 * 1.414 = 254V, half of the peak voltage is 127V, which minus 30V that is the differential pressure buck, its maximum output is 90V, so the number of series LED lamp is up to 28 strings. Therefore, in order to obtain relatively large power factor, lamp beads series number is not too much, otherwise, it can not reach the low voltage requirements.
2, the current precision:
There are some power supply whose precision constant current is too bad on the market, such as the PT4107/HV9910/BP2808/SMD802 programs constant solutions that is popular in the market, error is ± 8% or ± 10%, constant error is too large. it generally require± 3%.As the 3% margin of error, 6-way parallel, each of the error is about ± 0.5%, if it is 12-way parallel, each of the error is about ± 0.25%, the accuracy is sufficient. High precision, the cost will be greatly increased. And for the LED, 17 mA and 17.5 mA have little impact.
3, isolation / non-isolation:
Generally speaking,the isolated power supply is made into 15W, which is placed inside the LED tube light, the volume of transformer is large, it is difficult to put. Especially for T6/T8 lamp, almost impossible, so the general isolation can be made into 15W, the few is more than 15W, and the price is very expensive. Therefore, the cost performance of the isolation is not high, more non-isolated is generally mainstream, the volume can be made into smaller, the minimum height 8 mm can be done, in fact, the safety measures of non-isolated is well done, it is not problematic.
4, the power efficiency:
Output power (output LED voltage * Output Current) / input power. This parameter is particularly important if the efficiency is low,which means that a large part of the input power is converted into heat that comes out; if it is mounted inside the tube ,there will be a very high temperature produce, combined with our LED light efficiency than that of a distribution of heat, it will produce a higher temperature superposition, as the temperature increases, a the life of all the electronic parts of our internal power supply will be shortened, so the efficiency is the most fundamental factor determining the life of the power,if the efficiency is too low, or too much heat will be consumed on the power supply. Generally above 80% is OK, however, the efficiency has to do with the connection of the light board.
5, Size:

The height is the main limiting factor, the height generally used to tubes T6 / T8 should not be too high, the dimensional requirements is ≤ 9 mm. T10 tube height is ≤ 15 mm. Length can be rather long, so that and it is easier to dissipate heat.

LED manufacturers should know who engage in producing and selling the LED light should master these considerations, for us ordinary consumers, we have to choose a prime quality LED manufacturers.Meanwhile,there are a large number of manufacturers specializing in developing and producing LED light, lead lighting is one of them,Lead lighting has been continuing to strengthen the use of certified raw materials such as  LED chips, LED drivers, heat sinks, shell, etc., and improve R & D and production team, striving to adopt the best materials and technology to produce best quality LED flood light, LED tunnel light, LED tube light and other indoor and outdoor lighting, using highly integrated high-brightness COB as the light source of the  LED Flood light and LED tunnel light and other outdoor lighting,adopting high brightness SMD LED as the light source of the LED tube light, the low-voltage constant current driver ensure the alternating current can be convert into direct current so that improve the energy use and reduces the stroboscopic effect stimulating the human eye, fully guarantee octahedron illuminated area of LED flood lights and bright light to adapt to outdoor open environment ,the soft and bright light of the LED tunnel light and LED tube light makes us safe driving in tunnels and enjoy work and study.As an ISO 9001:2000-certified factory,the lead lighting can meet the strict standards of CE, RoHS, FCC certificate, these strict producing standards guarantee our products distribute smoothly both in domestic and international markets. visit http://www.ledclan.com to Learn more vivid and specific characteristics of the LED tube light or click www.lead-lighting.com/products/bid32-1.htm for more detailed and professional features and uses of the LED tunnel light.

What need to be paid attention to when designing the LED tube light

Five common  questions of LED tube light

Current, LED tube light market is very active, the manufacturer is mainly divided into three categories: one is the original factory that manufacture LED chip, taking advantage of an opportunity to penetrate downstream,not much understanding on the knowledge of the circuit and the power of the LED tube light; II is that the factory originally doing general lighting has entered a new field, understanding some of the knowledge of the circuit; three is the factory that did other products or new business completely engaging in new entrants, and some understanding the LED power supply, and some do not. The power is the most important part of the LED tube light, improper selection, the performance of the LED fluorescent lamp can not be played, or even can’t be normally used.

1, why must constant:

The characteristics of LED semiconductor determines its influenced by the environment. such as the temperature rises, LED current increases, the voltage increases, LED current will increase. Working under the current over the rated for long time will greatly shorten the service life of the LED. The LED constant current is that ensure that the operating current is constant even if the environmental factors such as temperature and voltage changes.

2, the power match the light board of the LED tube light:

Some customers firstly design the light board, then find the power, it is difficult to find a suitable power, either too much current or the voltage is too small (eg I> 350mA, V <40V); either the current is too small, the voltage is too high (eg I < 40mA, V> 180V), the result is a severe fever, low efficiency, or the input voltage range is not enough. In fact, selecting  one of the most excellent string and connection mode make that the voltage and current added to each LED is the same so that the effect of power is able to play the best performance. The best way is tailoring prior to communicate with power supply manufacturers.

3, LED operating current:

The LED rated current is generally 20 mA, and some plants used to make the outset, designing 20 mA, in fact, the fever generated under this current is very serious, after numerous comparison test, 17 mA designed is ideal . The total current of N-way parallel = 17 * N;

4, LED’s operating voltage:

Generally speaking, the LED recommended operating voltage is 3.0-3.5V, tested, most of the work at 3.125V, so 3.125V is a more reasonable. The total voltage of M series LED = 3.125 * M

5, series and parallel LED light board and wide voltage:

For LED lamp operating at a relatively wide range of that the input voltage is AC85-265V, then the series and parallel mode of the light board is very important. Due to the current power is generally non-isolated step-down power, when require the wide voltage, the output voltage should not exceed 72V, the input voltage range can be reached 85-265V. That is, the serial number should be no more than 23 strings. Number of parallel must not too much, otherwise the high operating current generates too serious fever, and the 6/8 and / 12 is recommended .Not more than 240 mA total current is better. There is a wide voltage solution that is firstly using L6561/7527 to raise the voltage to 400V, then the buck, which is equivalent to two switching power, twice as expensive as the costs, the cost of this program is not high, there is no market.

Nowadays,the LED flood light and LED tube light is most widely used as the representatives of the home lighting and decorative lighting in daily life,the LED tube light enjoys a great popularity in our corridor, restaurants, shopping, leisure and entertainment, galleries, exhibition halls and other indoor environments everywhere, the LED flood light is mainly used in city squares, parks, stadiums, the facades of large commercial buildings and hotel, stage, waiting rooms, airports etc. where the higher brightness lighting is needed to illuminate. Lead Lighting adopts high brightness SMD as the light source of the LED tube and highly integrated and high brightness COB as the light source of the LED flood light, which fully guaranteed stability and soft light of the LED tube light and octahedron breadth and brightness irradiation range of the LED flood light, the low voltage constant current driver convert the AC into DC so that improve energy efficiency and reduce the waste heat energy and stroboscopic effect excite the human eye, the most important is that the LED tube light  and LED flood light without adding mercury and other heavy metals harmful to our body and pollution the environment, that’s why the LED light is famous for energy-saving and environmental protection login http://www.ledclan.com to learn more features and uses of the LED tube light and surf www.lead-lighting.com to know more awesome LED floodlights and other LED lighting.