How to effectively test the leds start, rising and stroboscopic effect

Due to the LED solid-state lighting products with good luminous efficiency, long life, high reliability features, unique and therefore more and more popular with the market and consumers. But at the same time due to the LED fast response speed, but also do not have the thermal inertia of lamps and lanterns and traditional afterglow effect, so deeply affected by the fluctuation of the current fluctuations in current directly affect the output of luminous flux, light blinking is the external embodiment of luminous flux change, so the LED lighting products of flicker problem has aroused the attention of all. On December 14, 2012, the eu formally released the first on its official gazette ( EU) Regulation NO 1194/2012 of the European parliament and the European Union council directive 2009/125 / EC about directional lights, LED lights and its related equipment detailed rules for the implementation of ecological design requirements. Corresponding to the commission released on March 18, 2009 the first ( EC) Regulation NO 244/2009 of the European parliament and the council's 2005th / 32 / EC instruction of non-directional household lights detailed rules for the implementation of ecological design requirements, thus the eu of leds to form the complete mandatory ecological design requirements. Start-up time and rise time as two indicators of functional requirements, more and more get the attention of the manufacturers in the industry.

just we have said to the scintillation effect of LED lighting products, but many people don't know what it means. Is the essence of the light blinking light flux fluctuation, substantial light source under the exchange or pulse dc drive, luminous flux, intensity of illumination brightness or cycles with the current amplitude of the corresponding change, the human eye to the brain response to the change of subjective. The feelings of people is flashing into visible flashing ( 可见闪烁) And not visible flashing ( 看不见的闪烁) 。 Frequency is greater than 100 hz, the human eye feel flicker phenomenon, but still can cause eye fatigue, headache, etc. , this is yan flash effect, this effect is generally believed that within 500 hz. The U. S. energy star ( 能源之星灯V1。 Zero draft 4 in dimming performance requirements specified in the conditions to be fulfilled, used for all lamps and lanterns. As shown in the figure below

light blinking allowed is

1, the range of frequency is not less than 120 hz;

　　2、120Hz- 800 hz frequency range, F1

3, when the frequency is greater than 800 hz, no request for F1;

4, frequency is uncertain, PF

in addition, the output frequency need a 20 - to compact fluorescent lights 30 KHZ, or greater than 40 KHZ.

light blinking light flux is the nature of instability. In detecting light fluctuate over time, can not only test the brightness change curve, also can test the change of light flux or curve in the same conditions. 能源之星( V1。 0) Specifies the flicker flicker measurement requirements

1, the power source and the measuring instrument, to meet the LM - 79 - 08 requirements;

2, with the function of storing multi-channel oscilloscope, and attenuation probe when necessary. Sampling rate is greater than 2 KHZ, sampling time is more than 100 ms;

3, photometric probe, V ( In) Correction, and the corresponding time to meet the requirements;

4, for absolute photometry ( 绝对光度法) Measure the absolute value need integrating sphere; For relative photometry ( 相对光度法) To ensure that the probe can measure the relative light output, and only accept from metering source of light.

before measuring, compact fluorescent lamps need burn-in 100 hours, need to preheat before measurement. LED lights without aging, environmental temperature of 25 + / - 5 degrees.

coordinating editor li jie

force shanyou electronic