1, what is the LED drive power LED drive power supply the power supply is converted into a certain voltage current to drive the LED voltage converter, normally: LED drive power supply input including high-voltage ac power frequency (
Dc, high-voltage direct current, low voltage, low voltage high frequency ac (
Such as electronic transformer output)
And so on.
And the output of the LED driver power supply are mostly can change with LED positive pressure drop values and change the voltage of the constant current source.
LED core components including power switch controller, the inductor, switch components (
, the feedback resistance, input filter, output filter parts, etc.
In accordance with the requirements of different occasions, also have input over-voltage protection circuit, input under-voltage protection circuit, LED open circuit protection, over current protection circuit, etc.
2, the characteristics of the LED drive power supply (
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.
LED is energy efficient products, the efficiency of the drive power supply.
For the power supply installed in the lamps and lanterns and 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.
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 the use of large amount of lighting at night, the same 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.
Drive way now prevailing are of 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.
LED anti surge surge protection ability 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.
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;
To conform to the requirements of safety and electromagnetic compatibility.
3, LED drive power supply according to the drive way classification (
Constant flow, constant current drive circuit, the output current is a constant, and the output dc voltage is different with the size of the load resistance within a certain range, load resistance is small, the output voltage is low, the greater the load resistance, the higher the output voltage.
B, does not fear the load constant current circuit short circuit, but it is forbidden to load completely open.
C, LED constant current drive circuit drive is ideal, but the price is relatively high.
D, should pay attention to use maximum current and voltage, it limits the number of using leds.
Voltage type a, when the voltage regulation circuit, to determine the various parameters of the output voltage is fixed, and the output current is as the load increase and decrease and change;
B, regulating circuit are not afraid of open load, but it is forbidden to load completely short circuit.
C, with voltage driving circuit to drive the LED, each string need to add the appropriate resistance can make average a string of LED display brightness;
D, brightness will be affected by rectification of voltage change.
4, the constant current and constant current work the advantages and disadvantages by road from the above comparison can also see that the road by constant current although drawback is more, the cost is high.
But it can really protect leds and prolong the life of the LED, so by constant current is the trend of the future.
5, LED drive power supply the deficiency of the LED driver power supply is also a product of form a complete set, currently on the market of power quality is uneven, according to the existing data query and project execution bad light problems encountered in analysis about the causes of deficiency of the LED drive power supply at present: a, production of LED lighting and related products of the company's technical staff understanding of switch power supply is not enough, the power supply can be normal work, but some critical evaluation and electromagnetic compatibility of the consideration is not enough, still has some hidden trouble.
B, most of the LED power supply production enterprise is from ordinary transformation come and do the LED power supply, switch power supply for LED characteristics and use of knowledge is not enough.
C, about the LED standard almost no at present, most of them are reference standard switching power supplies and electronic rectifier.
D, now most of the LED power supply is not regulated, so much quantity is small.
Small purchase quantity, the price is on the high side, also don't cooperate and components suppliers.
E, LED power supply stability, wide voltage input, high and low temperature, over temperature and over voltage protection and other issues are not solve one by one.
F, the first is driving circuit the whole life, especially the key parts such as: capacitance at high temperature directly affects the life of a power of life.
G, higher conversion efficiency is the LED driver should challenge, especially when driving high power leds even more so, because all not as light output power as heat dissipation, power conversion efficiency is low, influence the exertion of LED energy saving effect.
H, at present in the smaller power (
Applications, constant current drive power cost share is close to 1/3, is close to the cost of the light source, to some extent, affected the market promotion.