There are three compartments of LED down lamps that can determine their lifetime: LED beads (LED chips car led ), LED power supplies (LED drivers), cooling sections. LED beads are the core part of LED down lamps, which will directly determine their performances and service lives. Currently, most high quality LED beads are from Cree (American) and Nichia (Japan). Other LED chip manufacturers with higher cost performances are Epistar, Everlight from Taiwan and Sanan optoelectronics, Yingrui from the mainland.
Undoubtedly, Cree is the best LED chip manufacturers in the world, LED lights used these beads have higher output luminous flux, longer service life, but also higher selling prices. These products are more suitable for European and American markets. Chips from Taiwan are weaker than Cree chips in performances, but still have very long lifetime, can be afforded by customers from developing countries and regions, like the mainland, Southeast Asia and Mid-east.
LED power supplies are the heart of LED down lamps, having significant influences on them. LED down lights usually work under 110-220VAC. Since the development of LED lights is relatively shorter than other traditional lamps, the Chinese Government still has no uniformed standard for LED power supplies. Currently, LED power supplies that sold in domestic market have different qualities, different standards, many of which have very low power factor (PF) and cannot pass the EMC electrical tests. The lifetime of electrolytic capacitors within power supplies are directly determine the lifetime them. In order to reduce the cost as low as possible, producers tend to use low quality electrolytic capacitors, which will weak the efficiency of power supplies, making “long lifetime” LED down lamps become “short life” lights.
The cooling design of LED down lights also impacts their lifetime magnificently. Heat generated by LED beads will be conducted to PCBs and finally covers, then dissipated into the air though covers. Among these parts, it is the PCBs’ heat dissipation performances that determine the quality of cooling sections. PCB must have a higher thermal conductivity. The thermal conductivity of grease should be good enough. The cooling area of the enclosure should be large enough. Reasonable design of these parts can maintain the working temperature of PN junctions under 70 degrees, which can guarantee the normal working conditions of LED down lights.