Industry news

2016August

Some suggestions on the power supply of LED fluorescent lamp

From: www.szbako.com Data:06/08/2016

LED fluorescent lamp power supply is LED fluorescent lamp in very important a part, if the choice is undeserved, LED fluorescent lamp develop a he proper function, and even can not normal lighting application. Below I LED fluorescent lamp power to do some small suggestions, for your reference.


1, LED fluorescent lamp power why is it necessary to the constant flow of it? LED

semiconductor characteristics of the decision by the impact of the larger, such as temperature increases, the current will be added to LED; voltage to add, LED of the current will be added to

. Long time beyond the extra current task, will greatly shorten the life of the LED. And LED constant current is in the temperature and voltage and other factors of the changes in the

, to ensure that the current task is the same.

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

some customers first design panel lights, to find the source, found it difficult to have a proper 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), the consequences are severe fever, low efficiency, perhaps input voltage Bureau

limit is not enough. In fact, choose one of the most outstanding series and connection method, plus the voltage current on each LED is the same, and the results of the power supply can carry forward the most

good function. The best way is to first and power manufacturers to communicate, tailored.

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

ordinary led the additional tasks current of 20 mA, some factories start is used to do, 20 mA design and practice of the current task fever is very strict

Jun and several comparative experiments, designed to 17 ~ 19 Ma is unmatched fantasy, introduce design for 18 Ma.

4, LED fluorescent power supply of the task voltage is how much?

ordinary led recommended working voltage is 3.0-3.5V. After testing, large local task in 3.125V. So according to the formula of 3.125V nuclear match reasonable. Series parallel and wide voltage M

lamp series total voltage =3.125*M

5, LED lamp panel is wide? LED to make the

fluorescent lamp task in the input voltage is limited to a wide limit (full voltage) AC85 ~ 265V, then the light board LED series parallel method is very main

to. Because the current power supply for the ordinary non isolated buck type power supply, in the requirements of wide voltage, the output voltage does not exceed 72V, the input voltage is limited to

to reach 85 ~ 265V. That is, the number of series does not exceed 23 strings. The number of parallel tasks is not too much, otherwise the current is too large, have a fever severe, 6

and /8 and /12 for the referral and. The total current does not exceed 240 Ma as well. There is a wide range of voltage program, is to use the L6561/7527 to raise the voltage to 400V, then

after the buck, equivalent to two switching power supply, the cost of your one times, this program is not high, there is no market. What is the relationship between the series parallel connection of LED and

6 with the PFC power factor and the voltage of the voltage?

currently on the market of power factor correction (PFC) has three kinds: without special PFC circuit a, the PFC in general about 0.65; a is with passive
PFC circuit, lamp panel horses prepared well and PFC in general about 0.92; also used a is active type automatic 7527/6561 circuit PFC can reach the
0.99 but the cost is the second scheme is one times more expensive than. So many of the second programs. On the passive PFC circuit: also called the valley fill type
PFC circuit, the task voltage limitation is half of the AC input voltage peak. If the input is 180V, the peak is 180*1.414=254V.
peak voltage half 127V and then minus step-down pressure 30V, the maximum output is 90V, so the LED lamp series number 28 on. Therefore, in order to obtain comparatively
power elements, beads series number cannot be too much, otherwise, it is not up to the requirements for low voltage.


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

market some power constant current accuracy is poor, as prevailing in Tianshui PT4107/HV9910/BP2808/SMD802 scheme, such as the constant flow scheme, error
difference arrival & plusmn; 8% or & plusmn; 10%, constant error, too. General requirements in the ± 3% on it. 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 added. And the
to LED, 17 Ma and 17.5 Ma has little impact.

8, isolation /non isolated

common isolation power, such as the 15W, put in the LED tube, the transformer is very large, it is difficult to put in. In particular, the T6/T8 tube, it is impossible to
, so the ordinary isolation can only do 15W, 15W beyond the very few, and the price is very expensive. So the isolation of the price is not high, average length of isolation
accounted for more mainstream volume can be made smaller, the minimum can achieve high 8 mm, practice, non isolation of the safety measures well,
does not exist.

9, LED daylight lamp power efficiency

output power (output voltage of LED * output current /input power). This parameter is particularly important, if low efficiency means great
a locally transformed into heat distributed input power; if it is installed in the lamp will occur a very high temperature, plus we led a luminous efficiency than the
calorific value, the stack will be more high temperature. And our internal power supply all electronic parts of life rhyme with increasing temperature and shorten. So efficiency
is resolution power life the most basic factor, efficiency cannot be too low, or spend too much heat in the power supply. Common in more than 80% can be,
, but the efficiency of the lamp plate matching connection.

10, LED daylight lamp power supply size

height is the most important factor, the size of the common used for /T8 pipe T6 is not too high to be less than ≤ 9 mm. T10 tube height ≤ 15 mm.
length can be long, more easy to heat.
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