Types and uses of LED drivers

1.Classification

(1) Divided by power supply voltage: high voltage AC85-265V, low voltage 1.5-36V.

(2) Divided by power supply method: constant voltage source and constant current source.

(3) Divided by the isolation relationship between input and output: isolated power supply and non isolated power supply.

(4) Divided by the relationship between input voltage and output voltage: boost type, buck type, buck boost type.

LED lights can not directly use the power supply like the traditional light source, and the drive circuit needs to convert the power supply to DC current to work. The type and structure of the LED driver circuit are related to the type of power supply, which is usually divided into two categories: DC power supply and AC power supply.

DC Power

Various types of dry batteries, rechargeable batteries, and solar cells that can directly provide DC current , which can be classified into the following forms based on the provided power supply voltage.

(1)Low voltage drive

It means that the LED lamp is driven by a voltage lower than the leading voltage drop of the LED lamp. Low voltage drive LED requires the voltage to be raised to a voltage value sufficient to enable the LED to operate. For low-power lighting devices such as LED, this is a common use case, such as LED energy-saving table lamps.Due to the limitation of the capacity of a single battery, it generally does not need a lot of power, but it requires the lowest cost and relatively high conversion efficiency.

(2)Transition voltage drive

Refers to the power supply voltage to the LED power supply value changes around the LED tube pressure drop, this voltage may sometimes be slightly higher than the LED tube pressure drop, sometimes may be slightly lower than the LED tube pressure drop. The power conversion circuit of the transition voltage drive LED should solve both the problem of boosting voltage and the problem of reducing voltage, and in order to work with a lithium battery, it also needs to have as small a volume and as low a cost as possible. Under normal circumstances, the power is not large, and the circuit structure with the highest cost performance is the reverse polarity charge pump converter.

(3)High voltage drive

It means that the voltage value of the power supply to the LED is always higher than the LED tube voltage drop. High voltage drive LED to solve the problem of voltage reduction, because the high voltage drive is generally powered by ordinary batteries, will use a relatively large power, should have as low a cost as possible.The optimal circuit structure of the converter is the series switching buck circuit.

AC power supply, which is the most valuable power supply method for LED lighting applications, is the popular application of semiconductor lighting must be solved a good problem, AC power supply used in LED drivers, generally through buck, rectification, filtering, voltage regulation (or steady current) and other links, so that AC power into DC power supply, Then through the appropriate drive circuit to provide the appropriate working current for the LED, but also have a relatively high conversion efficiency, a smaller volume and lower cost.

2.Application

LED power supply is widely used in street lights, tunnel lights, LED floor tiles, LED point light sources, LED grille lights, LED indoor lights, LED ceiling lights, buildings, roads and bridges, square building facilities, lawn lights, curtain wall lights, LED wall washing lights, desk lamps, hotel lights, sport lights, LED plant lights, aquarium lights, etc.

The information plane display includes LED display screens, display boards, dynamic billboards, simulated animations, sports venues, indicator lights and internal reading lights inside the carriage, brake lights outside the car, tail lights, turn signals, side lights, explosion-proof lamps, mining lights in mining production, etc.