What does a LED driver do?
LED driver is a kind of power supply, which is a device that provides power to electronic equipment, also known as power supply. It provides lighting power and power required by all components in the computer.
LED driver is widely used in:
1) LED Lights: Street lights, tunnel lights, LED grill lights, LED indoor lights, LED ceiling lights, buildings, roads and bridges, square construction facilities, lawn lights, curtain wall lights, mobile phones, computers, etc.
2) Information plane display: display panels, dynamic billboards, simulation animations, sports venues, indicator lights and internal reading lights in the carriage, brake lights outside the car, tail lights, turn signals, side lights, explosion-proof lamps, mining production Miner’s lamp, etc.
As the driving objects are different, the LED driver is different. Basically divided into constant voltage power supply and constant current power supply.
1) High Reliability: Especially like the driving power supply of LED street lamps, it is installed at high altitude, and maintenance is inconvenient and expensive.
2) High-efficiency: LED is an energy-saving product, as a result the efficiency of the LED driver must be high, which is particularly important for the structure of the power supply installed in the lamp. Because the luminous efficiency of the LED decreases with the increase of the LED temperature, therefore the heat dissipation of the LED is very important. If the efficiency of the LED driver is high, its power loss is small, and the heat generated in the lamp is small, which reduces the temperature rise of the lamp, and is beneficial to delaying the light decay of the LED.
3) High PF: High power factor (PF) is the requirement of the grid for the load. Generally, there are no mandatory indicators for electrical appliances below 70 watts. Although the power factor of a single electrical appliance with low power is low, it has little impact on the power grid, but everyone turns on the lights at night, and the same load is too concentrated, which will cause serious pollution to the power grid. For the 30W to 40W LED drier and power supply, there are certain index requirements for the power factor.
4) Current Driving Methods: There are two current 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 the failure of one LED does not affect the work of other LEDs, but the cost is slightly higher. The other is direct constant current power supply, with LEDs running in series or parallel. Its advantage is the first point of cost, but the flexibility is poor, and it has the problem of single LED failure without affecting the operation of other LEDs. The two forms coexisted for some time. The multi-channel constant current output power supply method will be better in terms of cost and performance, and may be the mainstream direction in the future.
5) Surge Protection: The ability of LED to resist surge is relatively poor, especially the ability to resist reverse voltage. It is also very important to strengthen the protection in this regard. Some LED lights are installed outdoors, such as LED street lights. Due to the activation of the grid load and the induction of lightning strikes, various surges will invade from the grid system, and some surges will cause damage to the LEDs. Therefore, the LED driver must suppress the intrusion of surges, and protect the LED from being damaged.
6) Protection Function: In addition to the conventional protection function of the power supply, it is better to increase the negative feedback of the LED temperature in the constant current output to prevent the LED temperature from being too high.
7) Protection: the lamp is installed outside, the LED driver’s structure should be waterproof and moisture-proof, and the shell should be resistant to sunlight.
8) Lifespan: The life of the driving power supply should be adapted to the life of the LED.
9) Safety Requirements: Meet the requirements of safety regulations and electromagnetic compatibility.
With the application of LEDs everywhere, the quality of LED drivers are continuously improved, and the performance is more and more in line with the requirements of LEDs.
