LED-driven horizontal adapter is a voltage converter that converts the supply of power adapter to a specific voltage and current to drive LED luminescence. Usually, the input of LED-driven power adapter includes high voltage power frequency AC (i.e. city power), low voltage DC, high voltage DC, low voltage high frequency AC (e.g. the output of electronic transformer), etc. 。 The output of the adapter of the LED driver power supply is mostly a constant current source which can change the voltage with the change of the forward voltage drop of the LED. The following is to provide some knowledge of LED driver adapter for new entrants.

 

1. What is an LED driver adapter?

 

LED driver power adapter converts the supply of power adapter to a specific voltage and current to drive the LED light-emitting voltage converter. Usually, the input of LED driver power adapter includes high voltage power frequency AC (i.e. city power), low voltage DC, high voltage DC, low voltage high frequency AC (e.g. the output of electronic transformer), etc. The output of the adapter of the LED driver power supply is mostly a constant current source which can change the voltage with the change of the forward voltage drop of the LED. The core components of LED power adapter include switching controller, inductor, switching component (MOSfet), feedback resistance, input filter, output filter and so on. According to the requirements of different occasions, there are also input over-voltage protection circuit, input under-voltage protection circuit, LED open-circuit protection, over-current protection and other circuits.


　　　　　　　　　　

 

 

2. Characteristics of LED Driver Power Adapter

 

(1) High reliability

 

Especially like the LED street lamp driver power adapter, installed at high altitude, maintenance is inconvenient, maintenance costs are also high.

 

(2) High efficiency

 

LED is an energy-saving product, the efficiency of driving power adapter is high. It is very important for the junction heat dissipation of the power adapter installed in the lamp. The efficiency of power adapter is high, its loss power is small, and the heat in the lamp is small, which reduces the temperature rise of the lamp. It is beneficial to delay the light fading of LED.

 

(3) High power factor

 

Power factor is the load requirement of power grid. Generally, there are no mandatory indicators for electrical appliances under 70 watts. Although the low power factor of single electrical appliances with small power has little influence on the power grid, the large amount of lighting used at night and the concentrated load of the same kind will cause serious pollution to the power grid. It is said that in the near future, there may be some power factor requirements for the 30-40 watt LED driver adapter.

 

(4) Driving mode

 

Now there are two kinds of current: one is a constant voltage source for multiple constant current sources, each constant current source for each LED power supply alone. This way, the combination is flexible, all the way to LED failure, does not affect the work of other LEDs, but the cost will be slightly higher. The other is the direct constant current power supply, which is the driving mode of "Zhongke Huibao". The LED runs in series or in parallel. It has the advantage of low cost, but poor flexibility, but also to solve a certain LED fault, do not affect the operation of other LED problems. These two forms coexist for a period of time. Multi-channel constant current output power supply mode will be better in cost and performance. Maybe it will be the mainstream direction in the future.

 

(5) Surge protection

 

The anti-surge capability of LED is relatively poor, especially the anti-reverse voltage capability. It is also important to strengthen protection in this regard. Some LED lights are installed outdoors, such as LED street lights. Due to the triggering and lightning stroke of power grid load, various surges will be intruded from the power grid system, and some surges will lead to the damage of LED. Therefore, the analysis of "Zhongke Huibao" plug-in charger in surge protection should have certain deficiencies, and as for the frequent replacement of power adapters and lamps, the LED driver power adapter should have the ability to suppress the invasion of surge and protect the LED from damage.

 

(6) Protection function

 

In addition to conventional protection functions, power adapter should add negative feedback of LED temperature in constant current output to prevent excessive temperature of LED, and conform to the requirements of safety regulations and electromagnetic compatibility.

Wendy
                                                                                                                                                                  2019-6-28

  Disclaimer: This article comes from individual, KRECO has the right of final interpretation.