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What is the Function and Principle of the LED Lamp Driver?

Date:2020.11.16   Views:2105

What is the LED driver ? I believe that many people have heard of LED lights, but they don't know much about its importance and function. For today, let's spread common sense together.

LED driver

LED is a solid-state light source. When a forward voltage is applied to both ends of it, the minority carriers and majority carriers in the semiconductor recombine, and the excess energy released will cause photon emission. Using different materials, LEDs with different colors can be made. LED is a kind of light emitting diode, in addition to its light-emitting characteristics, it also has the characteristics of ordinary semiconductor rectifier diodes.

If you compare a lighting fixture to a girl, then light distribution is her connotation, structure is her appearance, and electronics is her heart. Human beings have no life without a heart, and the role of power in the whole lamp is as important as the human heart. A good driving power supply can also determine the life of a lighting product.

Why should LED drive

1. LED lights cannot directly use the conventional mains grid voltage. Due to the characteristics of the LED light source, in order to meet the special voltage and current requirements of the LED, a specially designed voltage conversion device must be used to make the LED work normally. The lamp has a power drive mode that is different from traditional lamps.

Driving mode of LED lamp power supply

Constant current drive power

a. The output current of the constant current drive circuit is constant, but the output DC voltage varies within a certain range with the size of the load resistance. The smaller the load resistance, the lower the output voltage. The larger the load resistance, the output The higher the voltage.

b. The constant current circuit is not afraid of load short-circuit, but it is strictly forbidden to open the load completely.

c. It is ideal to drive the LED with a constant current drive circuit, but it is relatively expensive.

d. Pay attention to the maximum current and voltage values used, which limit the number of LEDs used.

 LED Driver

Regulated drive power supply

a. When the various parameters in the voltage regulator circuit are determined, the output voltage is fixed, but the output current changes with the increase or decrease of the load.

c. The voltage regulator circuit is not afraid of load opening, but it is strictly forbidden to short-circuit the load completely.

d. Drive the LEDs with a voltage-stabilizing drive circuit, and each string needs to add a suitable resistance to make each string of LEDs show an average brightness.

The role of LED driver

LED drive power is the key to LED lamps. It is like a person's heart. To manufacture high-quality LED lamps for lighting, you must abandon constant voltage drive LEDs. Constant current source drive is the best way to drive LEDs. It uses constant current source drive instead of connecting a current limiting resistor in the output circuit. The current flowing through the LED is not affected by external power supply voltage changes, environmental temperature changes, and discrete LED parameters. In this way, the current can be kept constant and the various excellent characteristics of LED can be fully utilized.

The LED constant current power supply is used to supply power to the LED lamps. Since the current flowing through the LED is automatically detected and controlled during the working period of the power supply, there is no need to worry about excessive current flowing through the LED at the moment of power-on, and no need to worry about the load short circuit burn Bad power supply.

Using constant current drive mode, it can avoid current changes caused by the change of LED forward voltage. At the same time, the constant current makes the brightness of LED stable, and it is also convenient for LED lighting manufacturers to ensure product consistency when implementing mass production. Therefore, many manufacturers have Fully aware of the importance of driving power, many LED lamp manufacturers have given up the constant voltage method, and chose a higher cost constant current method to drive LED lamps.