Views:4 Author:Site Editor Publish Time: 2021-01-04 Origin:Site
1. 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. The LED constant current is to ensure that its operating current value remains unchanged when environmental factors such as temperature and voltage change.
2. What is the most suitable working current of the LED street lamp power supply?
For example, the rated working current of 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.
3.LED street lamp power supply constant current accuracy
Some power supplies on the market have poor constant current accuracy. For constant current solutions such as popular recommended solutions on the market, the error reaches ±8%, and the constant current error is too large. The general requirement is within ±3%. According to the 3% design plan. Production power must be fine-tuned to achieve ±3% error.
4. 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.
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 on the specific situation. Generally, the isolation can only be 15W, and it is very expensive to exceed 15W.
Therefore, the cost-effectiveness of isolation is not high. Generally, non-isolated products dominate the 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 isolated power supply.
6. 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 relatively wide range of input voltage range AC85-265V, the LED series and parallel 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 raise 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.