With the application of LED dimming is more and more wide, the ensuing problems are also constantly impacting people's cognition. Such as: The effect of the PWM dimming on LED lamps and lanterns, will it reduce the life span of lamps and lanterns? Will the strobe light bring about harm to people's health? With the improvement of living standard and the continuous progress of science and technology, people have already jumped out of the requirement of simple lighting. We discuss these issues from the following aspects.
The problem and solution of LED dimming:
The human eye is usually able to perceive the light flashes of the frequency up to the same frequency, which is higher than that of the frequencies. Therefore, in the application of LED lighting, if the pulse signal frequency is lower than the low frequency component of the, the human eye will feel the flicker. Of course, in specific applications, there are many factors may cause LED lights to blink. In terms of the current very popular SCR dimming, the cause of the flicker is generally the circuit current is not up to the controllable silicon maintenance current caused, there are several reasons for the maintenance of current: 1 SCR after the conduction, because the circuit is not resistive, due to capacitance, inductance, there will be a current oscillation, when the current oscillation to lower than the SCR maintenance current, the thyristor can be controlled off, and then trigger. 2 SCR conduction, the current will slowly decline, the current to the silicon-controlled rectifier before the maintenance, because this time is very short, if the back circuit is still too late to work, the same will restart. 3 when the input voltage is lowered, the circuit current is also reduced to lower than the SCR maintenance current, the controllable silicon turn-off. The use of PWM dimming, if the frequency is higher than 100Hz, there will be no stroboscopic phenomenon. It is simple in application, high in efficiency, high in precision and good in dimming effect.
How does the PWM dimming affect the life of LEDs?
LED itself a long life, the PWM dimming does not damage the life expectancy of LED; even as the PWM dimming helps reduce the LED's calorific value, it can actually help prolong the life expectancy of LEDs. Of course, in the system design, the need to effectively detect and control the LED temperature, to ensure that the LED reliable work, reflecting its long life and low maintenance costs.
The effect of PWM dimming is simply described in the light of LED strobe and the effect on lamp life. Visible PWM dimming effect in many aspects are positive, I believe that with the continuous upgrading of technology, intelligent lighting will gradually more into life, change people's living habits, to create a more healthy, comfortable, intelligent light environment.