Heat dissipation analysis and scheme of LED lighting design

At present, how to dissipate heat is the core problem in LED product design. Let's take a look at how to analyze and control the heat dissipation problem in LED lighting design. First, LED lighting design heat dissipation analysis the design of LED lighting systems below 25 watts is generally used for desk lamps, living room spotlights, household dining lights, night lights, etc. Even so, most low-power LED lighting applications less than 25 watts will also require a certain degree of miniaturization. This often leads to higher power density, although its power consumption is not very large. In this case, sufficient heat dissipation management measures must be provided by improving the mechanical structure. In addition, high electrical efficiency also helps reduce power consumption. Another way to prevent LED from overheating for a long time is to adopt a dimming solution. In fact, in this power range, LED lights will replace halogen lamps and compact fluorescent lamps. In addition, in order to get rid of the heat dissipation problem, passive components sensitive to temperature changes must be removed. However, at present, most LED driver solutions originate from the power supply topology and are based on this, so the limitation of temperature range should be considered, because general products are usually based on commercial standards, but the lights must be able to adapt to harsh environments. Second, the heat dissipation control scheme in LED lighting design in the rapidly developing LED lighting design, most people focus on highlighting (HB)LED dimming control strategy. However, the nature of HBLED lighting applications requires us to shift more attention to heat dissipation control. Although LED manufacturers are reducing the technical barriers to HBLED lighting design by significantly increasing the lumen per watt, compared with light output, there is still more electricity converted into heat to be emitted. Therefore, an overall strategy for heat dissipation management is needed to ensure that the heat emitted by the LED can be controlled as a function of temperature. Unlike incandescent lamps and tungsten bulbs, high-power LED does not radiate heat. In contrast, the LED conducts the heat of its PN junction to the heat dissipation metal block of the LED package. Since the heat generated by LED is emitted by conduction, it takes a longer and more expensive path to completely emit the heat into the air. At present, a big obstacle to the commercialization of HBLED Universal Lighting is the problem of heat dissipation. Therefore, whether this problem can be solved thoroughly and effectively can be said to be the key to win customers. The electronic control circuit must be able to handle trigger point settings and gain settings. In fact, LED needs to be able to cope with three potential heat dissipation sources: self-heating, ambient temperature and LED electronic control. The method of using variable resistor as dimming element is also unrealistic for HBLED, because the power consumed on the resistor is too large and a special winding resistor is required. When the resistor is very close to the position of the LED, the additional heat generated by the resistor will only make the heat dissipation problem more serious. The conduction element can also be a transistor, showing that its power consumption occurs on the transistor instead of the variable resistor. This method provides more flexibility by generating logarithmic response and negative or positive temperature coefficient thermistor for thermal control and brightness definition. The simple realization method of LED heat dissipation control using thermistor adopts a PTC element. PTC elements increase the nominal low resistance as temperature increases until their trigger point.