Analysis of the key problems in the design of LED lighting power supply

In the design of LED lighting power supply, there are several design problems: electrolytic capacitor life and LED does not match, LED light flashes in the common causes and treatment measures, PWM dimming of LED life, what is the effect of using TRIAC dimming control LED brightness potential problems.

LED lighting is an important consideration is that the LED driver circuit and the working life of the LED itself should be able to compare. Although there are many factors that affect the reliability of the drive circuit, the electrolytic capacitor has a crucial impact on the overall reliability. In order to prolong the working life of the system, it is necessary to analyze the capacitance in the application and select the appropriate electrolytic capacitor.

In fact, the effective working life of the electrolytic capacitor is largely affected by the ambient temperature and the internal temperature rise caused by the ripple current acting on the internal impedance. The rated life of the electrolytic capacitor provided by the electrolytic capacitor manufacturer is based on the conditions of exposure to the highest rated temperature and the maximum rated ripple current. At 105 C, the rated life of a typical capacitor may be up to 5000 hours, and the lower the working stress of the capacitor, the lower the rated level. Therefore, on the one hand, it is possible to extend the operating life of the electrolytic capacitor, which has a long service life and is capable of withstanding a high rated operating temperature. On the other hand, according to the actual stress and working temperature, still can choose a relatively low capacitance rated temperature and rated life, so as to provide a lower cost solution; from another perspective, consider maintaining proper stress and temperature in the design, can effectively prolong the working life of the electrolytic capacitor. It can match with the LED life.