LED is the English abbreviation of "LIGHTEMITTINGDIODE", Chinese referred to as light emitting diodes, because it has the advantages of environmental protection, long service life, high photoelectric efficiency ( the light effect has reached 100LM / W ), seismic and many other advantages, in recent years in the industry application to rapid development, theory, LED service life about 100000 hours, but the in the process of actual application, some LED lighting design of LED driving power insufficient understanding or improper selection or blindly pursue low-cost, resulting in LED lighting product life shortens greatly, poor LED lamp life of less than 2000 hours, some even less, resulting in LED lighting advantage cannot get very good play.
As a result of LED processing and manufacturing of particularity, lead to different manufacturers and even with a manufacturer in the same batch of product in the production of LED current, voltage characteristics have great individual differences. Now with high power white 1W LED typical specifications as example, according to the LED current, voltage variation to do a brief description, general white 1W application forward voltage of about 3.0-3.6V, that is to say, when nominal1W LED flows through a350 ma current, the voltage across it in 3.1V, and possibly also in3.2V or 3.5V may also be other values, in order to ensure the life of 1WLED, the general LED manufacturers recommend lamp factory using 350mA current to drive, when using LED ends of the forward current up to 350Ma, LED ends of forward voltage small increase, will enable the LED forward current substantially rise, make LED temperature become the straight line rise, thereby accelerating the LED light, the LED shortened life expectancy, or even damage the LED . Because LED voltage, current variation specificity, thus to drive LED power put forward strict requirements.
Constant current source driver is the best LED drive means, using constant current source driver, not in the output circuit is connected in series with a current limiting resistor, LED current through the external power supply voltage is not change, the temperature change of the environment, as well as the LED parameter discretization effect, which can keep the current constant, give full play to the LED various excellent characteristics.
Using LED constant current power supply for LED lamp power, because the power during the work will automatically detect and control the current flowing through LED, therefore, do not worry about the electrifying moments have excessive current flows through the LED, also do not have to worry about load shorting out the power.
Some manufacturers to worry about power supply driving plate selection of electrolytic capacitors will affect the life of the power supply, is actually a misunderstanding, for example: if the choice of105 degrees, life of 8000 hours of high temperature electrolytic capacitor, according to the passage of the electrolytic capacitor life estimation method "for every10 degrees lower, life doubled", then it is95 degrees in the environment work life of 16000 hours, in85 degree environment working life of 32000 hours,75 degrees in the work life of 64000 hours, if the working temperature is lower, so life will be longer! Therefore, as long as the choice of high-quality electrolytic capacitor to drive the life of the power supply is not affected! Led Kitchen light
Another point worth LED lamp enterprises note: due to the LED in the course of their work will release a lot of heat, so that the tube core node temperature rise quickly, LED power is high, the heat effect. LED chip temperature will cause a light emitting device performance variations and the conversion efficiency of attenuation, even a serious failure, according to the test results show: LED ¡¯s temperature rise by5 degrees Celsius, the luminous flux is decreased by 3%, so the LED lamps must pay attention to LED light source heat dissipation work itself, the possible increase of LED light source the radiating area, reduce the working temperature of the LED itself, if conditions allow, can be the best power part and the light source portion spaced apart, the pursuit of small volume and neglect the lamps and power working temperature is not desirable.
