LED driver is a power converter that converts the power supply into a specific voltage current to drive LED light. Normally, the input of LED driver includes high-voltage industrial frequency ac (i.e. power supply), low-voltage dc, high-voltage dc, low-voltage high-frequency ac (such as the output of electronic transformer), etc.The output of the custom LED driver China is mostly a constant current source that can change the voltage with the change of LED forward voltage drop.
Buying a drive is important for two reasons
A: to identify the brand of capacitance
Two: whether to take IC control chip, because the IC control chip has to stop short circuit, overvoltage, overload, overtemperature and other protection functions.
As long as these two points are in place on the drive, the quality has been very good.
The following considerations should also be taken into account when selecting an LED driver:
General principles
A. according to the characteristics of LED current and voltage, it is ideal to use a constant current LED driver. It can avoid the change of current caused by the change of LED forward voltage, and at the same time, the constant current makes the brightness of LED stable.
B. In addition, LED light flux is inversely proportional to temperature, so the heating of power supply and well-designed cooling system should be minimized in use.Thereby reducing the ambient temperature of LED operation.
C. In order to ensure the overall life of LED products, the junction temperature of LED must be controlled within a certain range, that is, the working environment temperature of LED products should be well controlled.
1 high reliability
LED products are mainly composed of LED chip and power supply, cooling housing, control circuit and so on.The quality of LED power supply directly affects the quality of the product.In particular, LED street lamp products are not convenient for maintenance because they are installed at high altitude, and the cost of maintenance is also large.
2 high efficiency
LED is an energy-saving product, and the driver should meet the requirements of energy-saving.In particular, the power supply is installed in the structure of the lamps, especially important.Because the luminous efficiency of LED depends on the temperature of LED
Go up and go down.The efficiency of power supply is high, its consumption of power is small, in the lamp heat is small, also reduced the lamp temperature rise.It is beneficial to delay the light decline of LED.
3. Constant current driving mode
In order to match the volt-ampere characteristics of LED, the LED power supply must be driven by constant current.
4 surge protection
LED impact resistance capacity is relatively poor, so we should strengthen this aspect of protection.In particular, some products installed in the outdoor, the grid load of the start and stop and lightning will have an impact on the power supply.Therefore, the input of the LED driver should have a protective circuit to suppress the surge, so as to prevent the switch from damaging the LED instantly.
5. Temperature protection function
In addition to the normal protection function of the power supply, the LED chip temperature negative feedback is added in the constant current output to prevent the temperature of the PN junction of the LED chip from being too high.
6 LED power life
In order to improve the life of LED driver, it is necessary to improve it from many aspects: use the capacitor with a higher life, improve the power efficiency, perform the cooling function of the power supply, and optimize the cooling design of the lamp.LED power supply belongs to switching power supply, the quality and reliability of switching power supply depend on its circuit design, production process, and the quality of the device.Electrolytic capacitor is an essential component of high power switching power supply.The normal working life of the switching power supply depends on the life of the electrolytic capacitor used by the power supply, and the life of the electrolytic capacitor depends on the life and working temperature of the capacitor itself. The working life of the electrolytic capacitor varies greatly at different temperatures.
7 work environment
Due to the different environment in different places, the environment of LED lighting workplace should be taken into consideration, such as temperature, humidity, installation location, etc.Considering the working mode of the power supply, if the soft start circuit is not added, the output will have a voltage peak at the moment of energize.For better protection of LED, soft starter circuit is needed.This is a key factor for the stability of outdoor LED driver.
Outdoor Led Driver
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