Ten characteristics of LED street lights
Why must the LED street lamp power supply have a constant current?
The characteristics of LED lighting materials determine that they are greatly affected by the environment. For example, as the temperature changes, the current of the LED will increase, and the increase of the voltage will increase the current of the LED. Long-term work beyond the rated current will greatly shorten the life of the LED lamp beads. And LED constant current is to ensure that its operating current value remains unchanged when environmental factors such as temperature and voltage change.
LED street lamp power supply constant current accuracy
The constant current accuracy of some power supplies on the market is poor, and the constant current schemes such as popular recommended schemes on the market have an error of ±8%, and the constant current error is too large. The general requirement is within ±3%. According to the 3% design plan. The production power must be fine-tuned to achieve ±3% error.
Working voltage of LED street light power supply
The recommended working voltage of general LEDs is 3.0-3.5V. After testing, most of them work at 3.2V, so the 3.2V calculation formula is more reasonable. The total voltage of N lamp beads in series=3.2*N
What is the most suitable working current of the LED street light power supply
For example, the rated working current of the LED is 350 mA. Some factories use it up at the beginning. The design is 350 mA. In fact, it is very hot to work under this current. After many comparison tests, it is ideal to design it to 320 mA. . Minimize the amount of heat generated, so that more electrical energy becomes visible light energy.
How wide is the series-parallel connection and wide voltage of the LED street lamp power supply board
To make the LED street lamp power supply work in a wide range of input voltage range AC85-265V, the LED series-parallel connection mode of the light board is very important. Try not to use a wide voltage, which can be divided into AC220V and AC110V as much as possible, so as to ensure the reliability of the power supply.
There is also a wide voltage scheme. APFC active power compensation is to use L6561/7527 to increase the voltage to 400V first, and then step down, which is equivalent to two switching power supplies. This program is only used under certain conditions.
Isolated/non-isolated
Generally, the isolated power supply is made into 15W and placed in the LED street lamp power tube. The transformer is very large and difficult to put in. The space structure depends mainly on the specific situation. Generally, the isolation can only be 15W, and it is rare to exceed 15W, and the price is very expensive.
Therefore, isolation is not cost-effective. Generally, non-isolated ones are more mainstream, and the volume can be made smaller, with a minimum height of 8 mm. In fact, non-isolated security measures are in place and there is no problem. Space permitting can also be used as an isolated power supply.
How can LED street lamp power supply match the lamp bead board?
Some customers design the light board first, and then look for the power supply. They find that it is difficult to have a suitable power supply. Either the current is too large and the voltage is too small (such as 7X1WI>350mA, or V<20V); or the current is too small and the voltage is too high (such as I<200mA or V>25V), the result is serious heating, low efficiency, or insufficient input voltage range.
In fact, choose the best series-parallel connection method, the voltage and current applied to each LED are the same, but the power supply effect can exert the best performance. The best way is to communicate with the power supply manufacturer first, and tailor it. Or produce your own power supply.
LED series and parallel connection and PFC power factor
The number of LED street lamp power beads in series should be up to 45 strings or less. Therefore, in order to obtain a relatively large power factor, the number of lamp beads in series should not be too small, otherwise the best working condition will not be achieved. The number of series connected on the isolated power supply is related to the number of turns of the secondary winding, which must be done. The power of the power supply must meet the output power.
The smaller the working current of the electronic components in the rated voltage working range is, the longer the heating is, the longer the service life is, and vice versa, the shorter the service life. LED street lamp power beads are very sensitive to the amount of AC, the higher the amount of AC, the worse the light comfort.
Generally, electrolytic capacitors are used to maintain the voltage, and the amount of AC output voltage should be reduced as much as possible. The electrolytic capacitor capacity at the bottom voltage side should not be too small. The ratio of capacity to output current is 1UF<1.5MA, otherwise the LED will flicker. The selection of non-isolated input end high voltage electrolytic capacitor is the same as that of isolated type, and the output end capacitance is 1UF<6MA. The electrolytic capacitor at the output end of the dimming LED power supply should meet 1UF<0.5MA.
LED street light power supply efficiency
Input power minus output power value. This parameter is particularly important. The larger the value, the lower the efficiency, which means that a large part of the input power is converted into heat and emitted. Therefore, efficiency is the most fundamental factor that determines the life of the power supply. The efficiency cannot be too low, otherwise the heat consumed on the power supply is too large. The efficiency of the non-isolated type is higher than that of the isolated type, generally above 80%. However, the efficiency is related to the matching connection method of the light board.
LED street light power supply cooling
The main factor of the heat dissipation scheme is that the LED street lamp power beads can greatly extend the life when they are used under overheating conditions. Generally, aluminum alloy is used, which is easier to dissipate heat. That is, the LED street lamp power beads are attached to the aluminum substrate, and the external heat dissipation area is maximized.
Facing such a vast LED market is really full of vitality, mainly for scientific development, and can achieve a leading position in certain technical fields. I believe that my country’s LED companies will become more powerful.
Benwei Solar Street Lights Outdoor Lamp
Product Features:
>LED light, solar panel, lithium battery and controller,all in one compact design.
>No wiring,100% solar powered ,easy to install and ship.
>Built-in infrared sensor,can adjust the light output automatically(time control + light sensor control+ motion sensor control).
>Rust-proof, dustproof and waterproof IP65.
>5 years warranty.
