1. High reliability, especially for the driving power supply of LED street lights, which are installed at high altitudes, making maintenance inconvenient and costly.
2. High efficiency LEDs are energy-saving products, and the efficiency of the driving power supply should be high. The structure of installing the power supply inside the lamp is particularly important. Because the luminous efficiency of LED decreases with the increase of LED temperature, the heat dissipation of LED is very important. The power supply has high efficiency and low power consumption, resulting in less heat generation inside the lamp and reducing the temperature rise of the lamp. Beneficial for delaying the light decay of LEDs.
3. High power factor is the requirement of the power grid for the load. Generally, there are no mandatory indicators for electrical appliances below 70 watts. Although individual appliances with low power have a lower power factor and have little impact on the power grid, lighting up at night and concentrating similar loads can cause serious pollution to the power grid. For LED driver power supplies ranging from 30 watts to 40 watts, it is said that in the near future, there may be certain requirements for power factor indicators.
There are two common driving methods: one is to use a constant voltage source to supply multiple constant current sources, and each constant current source supplies power to each LED separately. This method is flexible in combination, and if one LED fails, it will not affect the operation of other LEDs, but the cost will be slightly higher. Another method is direct constant current power supply, with LED series or parallel operation. Its advantage is that it has a lower cost, but its flexibility is poor. It also needs to solve the problem of a certain LED failure without affecting the operation of other LEDs. These two forms coexist for a period of time. The multi-channel constant current output power supply method will be better in terms of cost and performance. Perhaps it will be the mainstream direction in the future.
5. The ability of surge protection LED to withstand surges is relatively poor, especially its ability to withstand reverse voltage. Strengthening protection in this area is also important. Some LED lights are installed outdoors, such as LED street lights. Due to the initiation and shedding of power grid loads and the induction of lightning strikes, various surges can invade the power grid system, some of which can cause damage to LEDs. Therefore, the LED driving power supply should have the ability to suppress the intrusion of surges and protect the LED from damage.
6. In addition to conventional protection functions, it is recommended to add LED temperature negative feedback in the constant current output of the power supply to prevent excessive LED temperature.
7. In terms of protection, the external installation type of the lighting fixtures, the power structure should be waterproof and moisture-proof, and the shell should be sun resistant.
The lifespan of the driving power supply should be compatible with the lifespan of the LED.
