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LED daylight lamp - how to choose the power supply - how to configure - a compre

From: Data:29/08/2016

three LED fluorescent lamp driving power supply manufacturers will lead to the system defects:

first is development of LED chips and LED lights factory product quality, homeopathic downstream penetration, LED power supply circuit and LED fluorescent lamp power knowledge understanding is not much,

second class is had to do is to do ordinary lighting factory, to LED power supply circuit knowledge is not sufficient;

third class is switch to open a new factory, LED power supply for some limited understanding. Below I put in practice and learning (including network) found in some of the common problems summed up, welcome colleagues.

1, LED fluorescent lamp power why must the constant flow of it? It influenced by the environment determining the of

LED semiconductor properties, such as temperature, LED is a current sensor, LED current increases will directly lead to increased heating, long time more than rated current, the LED chip at the condition of high temperature in long time, will greatly shorten the service life of the LED. And LED constant current power supply can be guaranteed when the voltage and other factors change the operating current is unchanged, so as to protect the LED chip from high temperature damage, is the so-called — — power such as solution, easy to destroy.

2, LED fluorescent lamp power supply should be able to match with the light board?

some customers first design panel lights, to find the source, found it difficult to have a suitable power, or current is too large, the voltage is too small (such as I> 350mA, V <40V); or current is too small, the voltage is too high (such as I <40mA, V> 180V), caused by the result is severe fever, low efficiency, or input voltage range is not enough. Choose an appropriate string and connection mode, in each LED lamp voltage and current are the same, and the effect of the power supply can play the best performance. The best way is to first and power manufacturers to communicate, tailored.

3, LED fluorescent lamp power supply of the working current is how much is the most appropriate?

General LED lamp rated working current of 20 mA, some factories start is used to do, design 20 mA, in fact, this current work fever is very serious, the multiple comparison test, designed to 17 ~ 19 Ma is ideal, the design recommendations for 18 Ma, in order to ensure the life of the product higher than similar products many, although the cost will be increased by a few percent. What is the working voltage of

4, LED fluorescent lamp power supply?

General LED lamp beads recommended operating voltage is 3.0-3.5V, tested, most of the work in the 3.125V. So according to the 3.125V calculating type is reasonable. The total voltage =3.125× M lamp series; series parallel with wide voltage M

5, LED lamp panel is wide?

usually LED fluorescent lamp need to adapt to the wide input voltage range such as AC85 ~ 265V, so panel lights LED lamp series parallel manner is very important. As the current power supply is generally non isolated buck power supply, in the requirements of wide voltage, the output voltage should not exceed 72V, the input voltage range can reach 85 ~ 265V. That is, a series of not more than 23 series. Parallel number not too much, otherwise the work current is too large, serious fever, recommended for 6 and /8 and /12. The total current is not more than 240 Ma as well. There is a wide range of voltage programs, is to use the L6561/7527 to raise the voltage to 400V, and then buck, the equivalent of two switching power supply, the cost of your one times, this program is not high price, no market. What is the relationship between

6, LED series parallel connection and PFC power factor and wide voltage?

7, LED daylight lamp power supply constant current accuracy how much is the most appropriate?

constant current error is generally required in ± 3%. Market on the constant flow of the power supply is too poor, as popular in the market, such as constant flow PT4107/HV9910/BP2808/SMD802 program, the error of ± 8% or ± 10%, constant current error is too large. According to 3% of the error, 6 parallel, each error is about ± 0.5%, if it is 12 parallel, each path of the error of about ± 0.25%, the accuracy is enough. Accuracy is too high, the cost will be greatly increased. But for the LED lamp, the difference between 17 Ma and 17.5 Ma is not too large.

8, isolation /non isolated

in general, such as isolated power supply 15W, placed in the LED tube, the transformer is a large volume, it is difficult to put into. Especially for T6/T8 tubes, almost impossible, so the general isolation can only do 15W, more than 15W, and the price is very few, and the price is very expensive. So the isolation of the price is not high, generally non isolated accounted for more mainstream, the volume can be made smaller, the minimum can achieve high 8 mm, in fact, non isolated security measures well, is not a problem.

9, LED daylight lamp power efficiency

output efficiency = output voltage LED × output current /input power. This parameter is very important, because the LED fluorescent lamp is a big selling point is the energy saving. Power efficiency is low, then also installed in the lamp emits a lot of heat, so that the temperature balance after elevated temperature power supply, the power components accelerated failure, shorten the service life of components, and then affects the life of power supply, and ultimately affect the service life of LED fluorescent lamp; also sent by the power supply hot also make LED chip temperature increases, the LED fluorescent lamp lumen, will eventually lead to a shortening of the life of the product. In summary, the power efficiency is an important factor in the life of LED fluorescent lamp life, generally in more than 80% even OK, in addition, the efficiency of the matching connection with the lamp board.

10, LED daylight lamp power supply size

height is the main factor limiting, generally used for T6 tube /T8 the size of the requirements of the height can not be too high ≤ 9 mm. T10 tube height ≤ 15 mm. Length can be long, more easy to heat.

11, extend the LED daylight lamp power life of the idea of

first, choose a longer life of the power supply; second, switch to external power supply; third, the use of plug and play built-in power. From "the popularity of LED fluorescent lamp of how long the road"