LED driver power supply in the application of the LED lamps and lanterns - (AddTime - 2013-03-21)

LED or light emitting diode, due to it has environmental protection, long life, high photoelectric efficiency (the luminous efficiency has reached 100 lm/W), seismic, and many other advantages, rapidly developed in recent years, applications in various fields, in theory, the service life of the LED in the 100000 hours, but in the process of practical application, some LED lamps and lanterns design personnel understanding of LED drive power supply is insufficient or improper selection or pursuit of low cost, LED lamps and lanterns is greatly shorten product life as a result, LED lamps and lanterns of poor life of less than 2000 hours, or even lower, the result makes the advantage of LED lamps and lanterns is not very good play.

Due to the particularity of the LED manufacture, LED to different manufacturers and even the same manufacturer in the same product in the production of the LED current, voltage characteristics all have large individual differences. Now in typical specifications high-power 1 w white LED, for example, according to the LED current, voltage change rule to do brief description, generally 1 w white light application forward voltage of 3.0-3.6 V or so, that is to say, when nominal for the 1 w leds through the current 350 ma, it may at the ends of the voltage at 3.1 V, may also be at 3.2 V or 3.5 V also can be other values, to ensure the longevity of wled 1, general LED lamps and lanterns manufacturer recommended factory use current of 350 ma to drive, when after the forward current of 350 ma at the ends of the through the LED, the LED on both ends of the increase in forward voltage is very small, can make the LED forward current sharply rise, LED, the temperature in a straight line rise, increasing the LED light failure, the LED life shorten, serious when even LED burn out. Due to the particularity of leds change of voltage, current, and therefore puts forward strict requirements on LED drive power supply.

Constant current source driving is the best way of 200W led Flood light , driven by constant current source, not in the output circuit in series current-limiting resistor, LED on the flow of current is not affected by the outside power supply voltage, ambient temperature changes, and the influence of LED parameter discreteness, thus can keep current constant, give full play to the LED all kinds of good qualities.

Using LED constant current power supply power to the LED lamps and lanterns, because working in the power supply during the current through the LED will automatically detect and control, therefore, does not have to worry about electric current to flow through the LED at the instant of the electricity is too high, also don't have to worry about load short circuit burned power supply.

Some worry the power driver board manufacturer chooses electrolytic capacitor will affect the service life of power, in fact is a kind of misunderstanding, for instance: if choose 105 degrees, for high temperature electrolytic capacitor, 8000 hours of life, according to the passage of the electrolytic capacitor life estimation method "for every 10 degrees below, double life", in 95 degrees it work under the environment of life of 16000 hours, in the work life of 32000 hours in 85 - degree environment, the working life of 64000 hours in 75 - degree environment, if the actual working temperature is lower, so life will be longer! It seems that as long as it selects high quality electrolytic capacitor to drive is no effect on the lifespan of power supply.

It is also worth note: LED lamps and lanterns of enterprises due to the LED will emit a lot of heat in the working process, make the tube core is junction temperature rising rapidly, LED the higher power, the greater the heating effect. LED chips will lead to the rise of temperature electro-optic conversion efficiency with the change of light emitting device performance attenuation, serious when even failure, according to the experimental tests show that the LED itself every 5 degrees Celsius temperature, flux fell by 3%, so the LED lamps and lanterns must work to pay attention to the heat dissipation of 200W led Flood light source itself, where possible, try to increase the cooling area of the LED light source itself, and minimize the working temperature of LED itself, if conditions allow, best can to separate power supply and light source part, blindly pursuit of small volume and ignores the working temperature of lamps and lanterns and power supply is not desirable.