Requirements for the selection of film capacitors used in LED lighting products

There are many types of LED lighting products, such as bulb, fluorescent lamp, industrial lamp, street lamp, etc. Some of the products have small use space and high temperature, so the required capacitors should also have small volume, high temperature resistance and good current and voltage resistance.

LED products inside the space is little, slow cooling, use for a long time will cause temperature backlog, need small volume, high temperature resistant film capacitor, but ordinary film capacitor heat resistance at 85 ℃ on the market, may can't stand high temperature making internal dielectric film contraction deformation, cause the loss of capacitor capacity and voltage current resistance. Therefore, the film capacitor made of material at 110℃ is selected, and the ultimate temperature resistance of this kind of film capacitor can reach 120℃.

Generally, LED lamps on the roadside and factory lamps should be powered on for a long time in 24 hours. However, due to the structure of thin-film capacitors, long working hours will attenuate the capacity to a certain extent, especially in the case of resistance and capacity lowering. The main reason is that when the film is wound, the gap between the film and the film will produce ozone when the electricity is turned on for a long time, which will oxidize the metal layer after the accumulation, resulting in the decrease of the capacity. Therefore, it is necessary to reduce the internal gap through high temperature hot pressure during the production, improve the sealing performance of the capacitor, and choose the plastic case to seal the product.

Common on the market of polyester film capacitor loss is high, temperature can reach more than 10 ℃, if long time used for communication breakdown, easy to heat the wastage of the capacitance than polyester and polypropylene film capacitor is 10 times smaller, low temperature rise, high resistance to impact strength, under the condition of high frequency ac has a good compression performance, so try to use polypropylene capacitor.