LED lighting is used for LED power source selection
Application of LED in lighting lamps and lanterns is more and more widely, and is superior to the traditional way of lighting the uniqueness of, in addition to improve the quality of life, improve the light efficiency and extend the service life of lamps and lanterns, with its unique function of adjustable light the change of the light color temperature and brightness, and fully meet energy application for its greatest strengths.
The lighting effect of LED lighting lamps depends on the LED light source and the power supply.
In general, the LED light source can be simply divided into two broad categories: LED diode light alone or with a resistance of LED diode light source, on application, sometimes LED light source is designed to a module containing DC - DC converter, and such a complex module is not in the scope of this article. If the LED light or LED diode module to separate itself, common dimming method to adjust the amplitude of input current in leds, so the selection of LED drive power supply should refer to this feature, Ming weft company HLG/characteristic of the family of ELG is current can be adjusted, and can be by external 1-10 VDC * 10 v PWM pulse width modulation or even only through an external a simple variable resistance to control the output current of the modulation. While another is equipped with a resistor LED diode light source (commonly known as leds or LED STRIP), article LED lights are widely used is a resistance of LED diode in series, so the voltage are relatively stable, so users can access any sold the rated voltage of power supply to drive the leds. The common LED lights are typically powered by 12VDC or 24VDC, but they may be difficult to apply to leds. This paper illustrates the use current amplitude adjustable light way of the application of drive in the article LED lights, also discuss some common problems that move light, and at the same time introduced the using pulse width modulation (PWM) output adjustable light LED power driver, Ming weft companies have launched and recognition in national technical innovation product of series of the family of PWM, is currently on the market the most appropriate and most simple article LED lamp dimming solution.
Common LED lighting conditions:
Sounds that move light seems to be a simple thing to do, in fact want to have good and smooth dimming performance is need to consider many factors, common LED dimming bad, there are a lot of (a) as shown in the list below:
common lighting problem
Dead travel is a frequent problem when LED lights are switched on by an LED power driver with an output current. Although when LED drive power supply unit is in full load condition (such as attached figure 1 - a) can be in very good condition, but when the LED driver is not in full, the light status is obviously not smooth.
Figure 1: an LED drive HLG 100 is connected to an LED lamp bar (a) with 100% full load (a), which produces the best performance. (b) the load is 70% - and it shows an imperfect adjustment. (c) the load is 30% - showing a poor adjustment result because the dimmer range is too narrow.
Output pulse width modulation (output PWM) solution
There is no problem with dead travel when LED lights are applied using LED lights under full load conditions. Above argument that‘s right, but not very practical, in fact often article LED lights in a variety of applications (decorative lighting/auxiliary lighting/advertising lighting) because of the length cannot be accurately estimated under the condition of use, so the application of the simplest and best solution is to should have the right to choose which has the function of the output pulse width of the PWM dimming LED drive power to realize the article LED lamp dimming demand. While the output brightness with dimming signal load cycle to reduce the brightness of the light changes, choose the important parameters of drive power supply is dimming parsing and the frequency of the output pulse width modulation PWM, minimum dimming ability should be as low as 0.1%, in order to achieve 8 bit resolution to comply with all of that move light LED lights article dimming applications, the output pulse width modulation PWM frequency is should be able to raise as much as possible, in order to prevent the table (1) light flicker problem, according to the relevant technical research literature reports, frequency suggest at least above 1.25 kHz, ghost visible to reduce human eyes flashing.