LED drive power
LED drive power is a power converter that converts the power supply into a specific voltage and current to drive LED light. Generally, the input of LED drive power includes high-voltage power frequency AC (that is, mains), low-voltage DC, high-voltage DC, low-voltage Frequency AC (such as the output of an electronic transformer).
The output of the LED driving power is mostly a constant current source that can change the voltage as the forward voltage drop of the LED changes.
According to the power consumption rules of the power grid and the characteristics of LED drive power, the following points must be considered when selecting and designing LED drive power:
1. High reliability Especially like the driving power of LED street lights, installed at high altitude, there is a waterproof aluminum housing driving power. If the quality is good, it is not easy to break, reducing the number of maintenance.
2. High-efficiency LEDs are energy-saving products, and the efficiency of driving power should be high. For power installation
LED drive power
LED drive power
The structure inside the luminaire is particularly important. Because the luminous efficiency of the LED decreases with the increase of the LED temperature, the heat dissipation of the LED is very important. The efficiency of the power supply is high, its power consumption is small, the heat generation in the lamp is small, and the temperature rise of the lamp is reduced. It is beneficial to delay the light decay of LED.
3． High power factor Power factor is the load requirement of the grid. Generally, there are no mandatory indicators for electrical appliances below 70 watts. Although the lower power factor of a single power consumer has a smaller impact on the power grid, everyone lights up at night, and similar loads are too concentrated, which will cause serious pollution to the power grid. For 30W ~ 40W LED drive power, it is said that in the near future, there may be certain index requirements for the power factor.
4． There are two driving methods: one is a constant voltage source for multiple constant current sources, and each constant current source supplies power to each LED individually. In this way, the combination is flexible, and LED failures along the way will not affect the work of other LEDs, but the cost will be slightly higher. The other is direct constant current power supply, LEDs run in series or parallel. Its advantage is lower cost, but poor flexibility. It also needs to solve the problem of one LED failure, which will affect the operation of other LEDs. These two forms coexist for a period of time. Multi-channel constant current output power supply method will be better in terms of cost and performance. Maybe the mainstream direction in the future.
5. Surge protection LED's ability to resist surge is relatively poor, especially its ability to resist reverse voltage. Strengthening this protection is also important. Some LED lights are installed outdoors, such as LED street lights. Due to the induction of the grid load and the induction of lightning strikes, various surges will be invaded from the grid system, and some surges will cause damage to the LEDs. Therefore, the LED drive power must have the ability to suppress the intrusion of the surge and protect the LED from damage.
6. Protection function In addition to the conventional protection function, it is best to add negative feedback of LED temperature to the constant current output to prevent the LED temperature from becoming too high.
7. In terms of protection, the lamps should be installed outside, the power supply structure should be waterproof and moisture-proof, and the shell should be resistant to sunlight.
8. The life of the drive power must be adapted to the life of the LED.
9. To meet the requirements of safety regulations and electromagnetic compatibility.
With the increasing application of LED, the performance of LED driving power will be more and more suitable for LED requirements.