Precautions of led lamp driver:
According to the characteristics of the power grid, the requirements of LED characteristics and related LED products, the following points should be considered when choosing LED driving power:
General principle
a. According to the characteristics of LED current and voltage, it is ideal to use constant current drive. It can avoid current changes caused by the change of the LED forward voltage, and at the same time the constant current makes the brightness of the LED stable.
b. In addition, the luminous flux of the LED is inversely proportional to the temperature, so the power supply should be minimized in use and a well-designed heat dissipation system should be used. Thereby reducing the ambient temperature of LED work.
c. In order to ensure the overall life of LED products, the junction temperature of the LED must be controlled within a certain range, that is, the working environment temperature of the LED product must be controlled well.
1. High reliability
LED products are mainly composed of LED chips and power supplies, heat dissipation shells, and control circuits. The quality of the LED power supply directly affects the quality of the product. Especially LED street light products, because they are installed at high altitude, it is inconvenient to maintain and the maintenance cost is also high.
2. High efficiency
LED is an energy-saving product, and the drive power must also meet the energy-saving requirements. Especially the structure of the power supply installed in the lamp is particularly important. Because the luminous efficiency of the LED decreases as the temperature of the LED increases. The efficiency of the power supply is high, its power consumption is small, and the heat generated in the lamp is small, which reduces the temperature rise of the lamp. It is beneficial to delay the light decay of LED.
3. Constant current drive mode
In order to match the volt-ampere characteristics of the LED, the LED power supply must be driven by a constant current.
4. Surge protection
The impact resistance of LED is relatively poor, so it is necessary to strengthen this protection. Especially for some products installed outdoors, the start and stop of the grid load and lightning strikes will have an impact on the power supply. Therefore, the input terminal of the LED drive power supply must have a surge suppression circuit to prevent the switch from damaging the LED instantly.
5. Temperature protection function
In addition to the conventional protection functions of the power supply, it is best to add negative feedback of the LED chip temperature to the constant current output to prevent the PN junction temperature of the LED chip from being too high.
6. LED power supply life
To improve the life of the LED driver power supply, it needs to be improved from many aspects: use a longer life capacitor, improve power efficiency, do a good job in the heat dissipation function of the power supply, and optimize the heat dissipation design of the lamp. LED power supplies are switching power supplies. The quality and reliability of switching power supplies depend on the circuit design, production process, and quality of the devices. Electrolytic capacitor is an essential part of high-power switching power supply. The normal working life of the switching power supply depends on the life of the electrolytic capacitor used in the power supply, and the life of the electrolytic capacitor depends on the life of the capacitor itself and the operating temperature. The operating life of the electrolytic capacitor varies greatly at different temperatures.
7. Working environment
Due to the different environments in various places, the environment of the LED lighting workplace should be considered, such as: temperature, humidity, installation location, etc.
Considering the working mode of the power supply, if the soft start circuit is not added, the output will have a voltage spike at the moment of power-on. In order to better protect the LED, it is necessary to add a soft start circuit. This is a key factor in the stability of the drive power supply
