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LED with low energy consumption, long life, low calorific value, environmental protection and other characteristics, has been widely applied in many field, such as:
1 lighting field street light, tunnel light, LED grille lamp, LED indoor light, LED ceiling lamp, etc
2 landscape lighting of buildings, bridge, square building facilities, lawn lamp, wall lamp, etc
3 as a back light mobile phone, computer, etc
4 information graphic display display board, billboards, dynamic simulation animation, sports venues, commerce and industry and other industries
5 cars car lights and internal reading lamp, car brake lights, tail lights, lights, side lights, etc
6 special application in the field of explosion-proof lamps, miner's lamp in mining production, etc

LED is a light-emitting diode characteristics, it can only be one direction electricity.Usually LED brightness output is proportional to the current by LED, but white LED in the big electricity flow saturation phenomenon appears, luminous efficiency greatly reduce, or even failure, so LED to use current rating should not exceed its specifications.In addition, the LED brightness output is inversely proportional to the temperature, so use in the design should try to reduce the power of fever and good cooling system.

Now LED by dc drive, so between the mains and LED need to add a power adapter or the LED driver power supply.Its function is to convert the ac mains to fit the LED of direct current.According to the rules of the grid electricity and LED driver feature requirements, in the choice and design of the LED drive power supply should consider the following:
1. The high reliability, special like LED street lamp driver power supply, in a high altitude, maintenance is not convenient, the cost of maintenance is also big.
2. LED is energy efficient appliances, drive power efficiency is higher.For the structure of the power supply installed in the lamps and lanterns, is particularly important.Because the LED luminous efficiency with the rising of LED temperature drops, so the LED heat dissipation is very important.Power supply of high efficiency, its power consumption is small, in the lamps and lanterns of calorific value is small, also lower the temperature of lamps and lanterns.Good for delaying the LED light failure.
3. High power factor power factor is the requirement of load of power grid.Generally below 70 watts of electrical appliances, there is no mandatory indicators.Though the power of a single use lower electric power factor, the impact on the grid is not big, but at night you light a lamp and its load is too concentrated, can produce serious pollution to grid.For 30 ~ 40 watts of the LED drive power supply, it is said that in the near future, may be the index of power factors have certain requirements.
4. Drive way prevailing now has two kinds: one is a constant voltage source for multiple constant current source, each constant-current source separately for each LED power supply.This way, flexible combination, LED failure all the way, don't affect the work of other leds, but the cost would be slightly higher.The other is a constant current power supply directly, leds in series or parallel operation.It has the advantage of low cost, but poor flexibility, but also solve a LED failure, does not affect other LED running problem.These two forms, for a period of time.Multi-channel constant current output power supply way, in terms of cost and performance will be better.Maybe the mainstream direction of the future.
5. The ability of anti surge surge protection LED is relatively poor, especially the reverse voltage resistance.Strengthening the protection is also very important.Some LED lights installed outdoors, such as the LED street light.As a result of the power grid load and sling and lightning induction, into the various surge from the grid system and some surge can cause the damage of the LED.So the LED drive power to suppress surge intrusion, ability to protect the LED was damaged.
6. Protection power supply in addition to the conventional protection function, the best in the constant current output increase LED temperature feedback, prevent LED temperature is too high.
7 protection type lamps and lanterns is installed outside, the power supply structure to waterproof, moistureproof, shell to fast.
8 the life of the drive power supply and LED the life of the adapter.
9 to accord with the requirement of safety and electromagnetic compatibility.

As the LED application is becoming more and more widely, the performance of the LED drive power supply will be more and more suitable for the requirements of the LED.