Views:77 Author:Site Editor Publish Time: 2020-03-03 Origin:Site
The LED drive power supply is a power converter that converts the power supply to a specific voltage and current to drive the LEDs to emit light. The inputs of the LED drive power include high-voltage power frequency AC power supply, low-voltage DC power supply, high-voltage DC power supply, low-voltage high-frequency AC power supply, and so on. The output of the LED driver power is mostly a constant current source which can change the voltage as the LED's forward voltage drop changes.
According to the power rules of the power grid and the characteristics of the LED driving power supply, the following points should be taken into account when selecting and designing the LED driving power supply:
Especially like the driving power supply for LED street lamps, it is installed at high altitude and has a waterproof aluminum shell driving power supply. If the quality is good, it is not easy to damage and it can reduce the number of maintenance.
LEDs are energy-saving products, and the efficiency of driving power supplies should be high. It is especially important for the structure in which the power supply is installed in the luminaire. Since the luminous efficiency of the LED decreases as the temperature of the LED increases, the heat dissipation of the LED is very important. If the power source has high efficiency, its power consumption is small, and the heat generated in the lamp is small, which reduces the temperature rise of the lamp. It is beneficial to delay the light decay of LEDs.
Power factor is the load requirement of power grid. Generally, there are no mandatory indicators for electrical appliances under 70 watts. Although the low power factor of single electrical appliances with small power has little effect on the power grid. But when people turn on the lights at night, the same load is too concentrated, which will cause serious pollution to the power grid.
There are two driving modes: one is multi-channel constant current output power supply mode, and the other is direct constant current output power supply mode. The first way means that each constant current source supplies power to each LED individually. In this way, the combination is flexible, and all the LED faults do not affect the work of other LEDs, but the cost will be slightly higher. The second way needs LEDs running in series or in parallel. Its advantage is that the cost is lower, but the flexibility is poor, and it is also necessary to solve a certain LED failure, which will affect the operation of other LEDs. These two forms coexist for a while. Multi-channel constant current output power supply mode will be better in terms of cost and performance.
The ability of LEDs to withstand surges is relatively poor, especially against reverse voltage capability. It is also important to strengthen protection in this area. Some LED lights are installed outdoors, such as LED street lights. Due to the grid load and the lightning strikes, various surges will be invaded from the grid system, and some surges will cause LED damage. Therefore, the LED driver power supply must have the ability to suppress the intrusion of surges and protect the LEDs from damage.
In addition to conventional protection functions, it is better to add negative feedback of LED temperature in constant current output to prevent excessive temperature of LED.
For the external installation of the lamp, the power supply structure should be waterproof and moisture-proof, and the outer casing should be light-resistant. The lifetime of driving power supply should match the lifetime of LED. The driving power supply should meet the requirements of safety regulations and electromagnetic compatibility.
With the increasingly wide application of LED, the performance of LED driver power supply will be more and more suitable for the requirements of LED.