LED lighting professional lighting and lighting project, both by the global environment and its professional particularity. The LED street light power supply is precisely the top priority of LED development. For the related planning of LED technology, there are already many plans and unique planning methods. Let's take a look at it one by one.
Why must LED street light power supply be constant?
The characteristics of LED lighting data are determined to be greatly affected by the environment. For example, if the temperature changes, the LED current will be added, the voltage will be added, and the LED current will be added. Long-term surpassing the extra current operation will greatly shorten the LED life of the LED. The LED constant current is to ensure that the operating current value does not change when environmental factors such as temperature and voltage change.
LED street light power supply constant current accuracy
The constant current accuracy of some power sources on the market is poor. Like the constant current schemes such as the popular referral plan on the market, the error reaches ±8%, and the constant current error is too large. The general requirement is ±3%. According to the 3% planning plan. The production power supply needs to be fine-tuned to reach ±3% error.
LED street light power supply operating voltage
The general LED recommended operating voltage is 3.0-3.5V. After testing, most of the operations are at 3.2V, so it is reasonable to calculate according to 3.2V. Total voltage of N lamp beads in series = 3.2*N
What is the most suitable operating current for LED street light power supply?
For example, the LED's extra operating current is 350 mAh. Some factories use it at the beginning, and plan 350 mA. In fact, the operation of this current is very hot. After repeated comparison tests, it is ideal to plan 320 mA. Minimize heat and turn more electrical energy into visible light.
LED street light power board series and parallel and wide voltage
In order to make the LED street lamp power supply work on the scale AC85-265V with a wide input voltage scale, the LED series-parallel method of the lamp board is very important. Try not to use a wide voltage, can be divided into AC220V, AC110V as much as possible, so as to ensure power reliability.
There is also a wide voltage scheme. APFC active power compensation is to first raise the voltage to 400V with L6561/7527, and then step down, which is equivalent to two switching power supplies. This plan is only used under certain conditions.
Barrier/non-blocking
Generally, the barrier power supply is made into 15W and placed in the LED street lamp power supply tube. The transformer is large in size and difficult to put in. Mainly depends on the specific structure of the space, the barrier can only be achieved 15W, less than 15W, and the price is very expensive.
Therefore, the cost performance of the barrier is not high, generally the non-blocking is more mainstream, the volume can be made smaller, the minimum can be 8 mm high, in fact, the non-blocking security measures are done, there is no problem. The space promises to also be able to block the power supply.
LED street light power supply can be matched with the lamp bead
Some customers first plan the light board, then find the power supply, and find that it is difficult to have a suitable power supply, or the current is too large, the voltage is too small (such as 7X1WI>350mA, or V<20V); or the current is too small, the voltage is too high (such as I<200mA or V>25V), the result is severe heat generation, low power, and perhaps the input voltage scale is not good.
In fact, to choose the best string parallel connection method, the voltage and current applied to each LED are the same, and the power supply can play the best function. The best way is to first communicate with the power supply manufacturer and tailor it. Or self-produced power.
LED series-parallel and PFC power elements
LED street light power bead series number is up to 45 strings or less. Therefore, in order to obtain a relatively large power factor, the number of series connection of the lamp bead should not be too small, otherwise the optimal operation condition will not be achieved. The number of series connection on the barrier power supply is related to the number of turns of the secondary winding, which must be done. The power supply should be satisfactory for the output power.
The smaller the operating current of the electronic component in the extra voltage operation scale, the longer the end of life, and the shorter the life. LED street light power beads are very sensitive to the amount of communication. The higher the communication volume, the worse the light comfort.
Generally, electrolytic capacitors should be used to maintain the voltage, and the voltage of the output terminal should be reduced as much as possible. The capacity of the electrolytic capacitor at the bottom end should not be too small. The capacity and output current share is 1UF<1.5MA, otherwise the LED will shine. The non-blocking input high-voltage electrolytic capacitor is selected in the same way as the blocking type. The output capacitor is 1UF<6MA. The dimming LED power supply is satisfied with 1UF<0.5MA at the output.
LED street light power supply power
This parameter is especially important for the input power minus the output power value. The higher the value, the lower the power, which means that a large part of the input power is converted into heat. Therefore, power is the most fundamental factor in determining the power life, and the power should not be too low, otherwise the heat consumed on the power supply is too large. Non-blocking power is higher than the barrier type, generally more than 80% can be, but the power is related to the matching method of the light board.
LED street light power supply cooling
The main element of the heat dissipation plan is that the LED street lamp power supply bead can be used in a hot condition to greatly extend the lifespan. Generally, the aluminum alloy is used, which is easier to dissipate heat. That is, the LED street light power bead is attached to the aluminum substrate, and the external heat dissipation area is maximized.
Faced with such a broad LED market is really full of vitality, mainly scientific development, in some areas of technology can get a leading position, I believe that China's LED companies will become stronger and stronger.