The second category: LED energy-saving lamps made of 3528 or 5050 chip power LEDs, power supply is also commonly used to resist the capacitance of the buck circuit, and some LED lamp manufacturers use constant current circuit, compared to straw hat type LED, SMD LED heat dissipation Slightly better, there is a heat-conducting substrate, and a part of the heat can be led out in conjunction with the aluminum substrate.
However, due to the neglect of the heat of the LED, many medium-power SMD LED energy-saving lamps, without a radiator, still use a plastic casing, the light fade is still serious. The RC is used to reduce the voltage of the grid, the current is fluctuating, the brightness is fluctuating, the price is moderate, and the quality is slightly better.

Three types: LED energy-saving lamps made of high-power SMD LEDs, the power supply generally uses a constant current isolation circuit, that is, there is a constant current, such as 5W LED, usually using 5 1 watt LED chips, connected in series, using constant 300mA current source, wide voltage power supply, when the power grid fluctuates, the current does not change, the luminous flux is the brightness is kept constant, 5 patch LEDs are soldered on the aluminum substrate, and the aluminum substrate is combined with the heat sink to use heat. Dissipate in time and quickly to ensure that the temperature of the LED chip is lower than the allowable junction temperature of the LED, thus ensuring the true and effective life of the LED energy-saving lamp. Such LED lamps are expensive and of good quality, and are also the development direction of LED energy-saving lamps.