In the rapid development of LED lighting design, most people focus on high-brightness (HB) LED dimming control strategy. However, HB LED lighting applications, the essential requirement that we will be more attention to the thermal control.
Although the LED manufacturers to substantially increase the number of lumens per watt HB LED lighting design is reduced technical barriers, but light output compared to more power still to be distributed out into the heat. Therefore, the overall need for a thermal management strategy to ensure that the LED the heat can be controlled as a function of temperature.
Curve in Figure 1 shows the typical 1W LED performance degradation characteristics. As expected, a clear indication that, by constant current LED driver, after reaching a certain point, the constant need to decrease linearly until this point at 150 ℃ to 0. Drop point and reduce the slope of the constant depends on mechanical / cooling arrangements.
Therefore, electronic control circuit must be able to handle the trigger point set and gain settings. Another very important point to remember is the fact that LED needs to be able to cope with the heat of three potential sources: from the heat, ambient temperature and LED electronic control. If LED lighting is used in the remote electronic control, then this would not be a problem, but EMC may be a problem.