Classification of LED energy-saving lamps
LED energy-saving lamps are called the fourth generation of lighting fixtures. Compared with ordinary energy-saving lamps, LED energy-saving lamps are environmentally friendly, mercury-free, recyclable, high luminous efficiency, long life, instant on, resistant to frequent switching, and low light decay. , rich colors, dimmable light, rich changes.
The classification of LED energy-saving lamps is mainly summarized into three categories:
1. LED energy-saving lamps made of 3528 or 5050 SMD medium-power LEDs generally use resistance-capacitance step-down circuits for power supply, and some manufacturers use constant-current circuits. Compared with straw hat-type LEDs, SMD LEDs have slightly better heat dissipation. The thermally conductive substrate, in conjunction with the aluminum substrate, can dissipate part of the heat. However, due to the neglected heat of LEDs, many medium-power SMD LED energy-saving lamps do not have radiators and still use plastic casings, and the light decay is still serious. Adopting resistance-capacitance step-down low-end power supply, because the grid voltage is unstable, the current fluctuates, and the brightness fluctuates, the price is moderate, and the quality is slightly better.
2. The LED energy-saving lamp made of straw hat type low-power LED, the power supply adopts the resistance-capacitance step-down circuit. The straw hat type LED continues to use the packaging form of the indicator LED, and the epoxy resin packaging makes the LED chip unable to dissipate heat, and the light decay is serious. After a period of use, the color temperature of many white LEDs becomes higher and gradually turns blue. become dim. There are also manufacturers who are committed to developing straw hat LEDs with low light decay, but because the packaging form has not been changed, the light decay has not changed much. Such LED energy-saving lamp products are transitional products with low price and poor quality.
3. For LED energy-saving lamps made of high-power SMD LEDs, the power supply generally adopts a constant current isolation circuit, that is, there is a constant current, such as 5W LEDs, usually using 5 pieces of 1W LED chips, connected in series, using constant current 300mA current source power supply, wide voltage power supply, when the power grid fluctuates, the current does not change, the luminous flux, that is, the brightness remains constant, 5 SMD LEDs are welded on the aluminum substrate, and the aluminum substrate is combined with the radiator. It dissipates quickly to ensure that the temperature of the LED chip is lower than the allowable junction temperature of the LED, thereby ensuring the real effective life of the LED energy-saving lamp. This kind of LED energy-saving lamps has high price and good quality, and is also the development direction of LED energy-saving lamps.
