An important reason for the low life of LED drive power supply is that the life of aluminum electrolytic capacitor required for the drive power supply is not enough. The main reason is that the ambient temperature inside the LED lamp is very high during long time operation, which leads to the electrolyte of aluminum electrolytic capacitor is quickly consumed, and the life is greatly shortened, generally only about 5000 hours. The service life of LED light source is 50000 hours, so the working life of aluminum electrolytic capacitor becomes the short rib of the service life of LED driving power supply.

In order to solve this problem, some suppliers have invented LED drive power supply without aluminum electrolytic capacitor. But not all LED driver power suppliers agree with this approach. At present, almost none of the mass-produced LED lighting drive power supplies adopt the drive scheme without electrolytic capacitor, because without it, many test standards can not pass, such as EMI test and flicker-free test.

The LED drive power supply scheme using aluminum electrolytic capacitor can easily pass the above tests. What if it is replaced with thin film capacitor, ceramic capacitor or tantalum capacitor? To achieve the same capacitance (generally 100-220UF), the film capacitance will be large and the cost will be too high. The ceramic capacitance is generally too small. If multiple ceramic capacitors are used to achieve such a large capacity, the plate area and cost will be too large. Tantalum capacitance should have such a large capacity. First, it is too expensive, but the withstand voltage is too low to meet the requirements. Therefore, to replace it with any other type of capacitance, it is basically not too large, but too expensive, If these shortcomings are replaced by capacitors with smaller capacity, the effect of eliminating ripple is not so good, and many export products cannot pass the strict certification test indicators required. Therefore, aluminum electrolytic capacitors are still widely used in high-quality LED drive power supply at present.

The LED drive power scheme without electrolytic capacitor claimed by many suppliers may only remove the aluminum electrolytic capacitor at the AC input end. The aluminum electrolytic capacitor at the constant current output end should be difficult to remove or replace.

In terms of the structure of LED drive power supply, Japan and the United States will take the non-isolated scheme as the mainstream, because their grid input voltage is only 110V. China and Europe will take the isolation scheme as the mainstream, because their grid input voltage is as high as 220V, and the safety of the isolation scheme is guaranteed, although the cost may be higher.