LED driving power using electrolytic capacitors led to low lamp life? It is a subject that has many opinions and endless controversies. LED driver power supply is generally divided into isolated and non-isolated type, in the utility power assembly lamps, due to security considerations, most customers choose to use isolated LED driver power supply, and the mass production of LED driver power supply in the market also Almost all use electrolytic capacitors for design.
The role of electrolytic capacitors in LED driver
The application of electrolytic capacitors in isolated LED driver power sources roughly distinguishes between primary (Cp) and secondary (Cs) capacitors and has energy storage and filtering capabilities. Apart from absorbing lightning strike energy and preventing the flicker caused by power transients, Cp's EMC countermeasures also have the effect of reducing EMI; while Cs is mainly filtered at the output side, it can reduce the output low-frequency current ripple and improve the flicker phenomenon. Currently, low-power LED driving power supplies commonly available in the market generally adopt Cp-free single-stage Flyback or PSR architectures in order to pass regulatory requirements for power factor and harmonic currents and low-cost requirements.On the circuit, because Cp is omitted, it is necessary to add additional countermeasure parts in the lightning strike test, and outputting high and low frequency ripple problems will not meet the requirement of low flicker (low frequency luminous flux change ratio less than 8%).
LED lamp life factor
The key factors affecting the life of LED lamps are nothing more than the electrolytic capacitors used in the lamp source and driving power supply, both of which are directly related to the temperature. The current commercial lighting fixture life is as low as 15,000 hours, and as many as 50,000 hours. According to data from LED manufacturers, the average life expectancy of high-power LEDs is estimated from the test results of LM-80 or TM-21, which is about 5 10,000 hours, and the life of the LED driver power supply depends on the level and temperature of the electrolytic capacitor used in the design, usually not less than the life of the LED, is a reasonable design choice.
It is not at all a problem that the design of the LED driving power source using electrolytic capacitors affects the life of the lamps.What is really important is that the lamp power supply must be selected and matched with a high-efficiency circuit design, and the LED drive power supply with high-quality electrolytic capacitors for the part design is the fundamental solution to the life of the lamp.