LED lighting cooling Questions
The current common incandescent bulbs or fluorescent lamps, even if the product itself is running may produce heat, but heat components can still be effectively isolated, light source and power connection seat will not produce heat and unexpected problems. But solid-state lighting is different, the one LED module on the running temperature of a single point, must take more active means of heat treatment, heat treatment simultaneously with active and effective mechanism in order to avoid a problem with the lamp. LED solid-state light heat treatment problem is much complicated than traditional lighting.
Or more than a traditional light fixtures generate heat during operation issues, such as halogen bulbs or incandescent bulbs, if incandescent form, that is heated in a tungsten lamp ball special treatment produces light.
In fact, rather than the high temperature generated in the filament lamp holder, lamp holder even due to light ball glass or metal tungsten light by the radiant heat, the heat conduction indirect high heat, but the temperature resulting in acceptable safety range, then With non-direct contact conduction, security is relatively high.
But replaced with LED solid state light source in the form of lamps, the treatment will likely become a new application security issues. Most people would think that LED with high energy conversion efficiency, low driving energy resources, natural use of high security, but in fact LED solid-state light source in order to achieve the purpose of the daily lighting of the application must be strengthened to increase the power unit through a single set of components lumen output elements, such as lighting plant will take the form of strengthening the integration of multiple LED component output, and multi-component running also improves LED solid-state light source type deflection point source problems, so LED solid-state lighting technologies can produce light such as light bulbs like surface lighting effects.
If you want to strengthen the lumen output unit members must be higher current to the LED chip PN junction produce more lumens, but higher currents also make single-point temperature LED components increases, more difficult to handle, even for improve the performance of light type, luminous efficiency lamps and adopt a multi-component and form, but also make high-temperature LED lighting intensifies the problem, so that the heat problem more difficult to handle.
Looking at the current development trend of LED lighting market, most LED light source manufacturers would most likely be market-driven, because of the high price, high profits, it can quickly enter through the development of the technical differences between the more avant-garde technology LED light source market, for example, for upholstery, situational lighting applications embedded lights, wall lamps, ceiling LED light fixtures became more common form of design, power efficiency to replace traditional lamps after its also the most relevant industry attention.
Thermal management design LED light fixtures must focus on process, where possible in a closed or semi-dense dead through the use of recessed lights, wall lamps, ceiling products, a more demanding challenge, lamps developers have from the material, product configuration, the main / passive cooling mechanism, drive chip design and other aspects to invest more resources in order to avoid the products in question Hajime students. LED Recessed Lighting especially small and often adopt a multi-component integration, high thermal design difficulty module. Recessed Lighting shell is aluminum extrusion or heat sink design, can play the role of autologous heat. But this is not enough.
LED thermal management: NTC maintain continuous operating temperature LED lights use safety
If the LED lamp does not come with sufficient thermal management design, during use may cause high fever running lamps because often caused by the sharp drop in life expectancy, resulting in frequent replacement of a defective LED lamps have problems, severe cases may even lead to accidents due to high temperature operation causing lines or the surrounding décor is burning!
In the product development stage, you can use intelligent LED lighting control technology, see temperature performance LED lamps with integral light source modules through active monitoring, simplify thermal management device, and when the temperature rises to the lamp and the surrounding zone, the Lamps must reduce electric power, reducing LED light output, in order to enhance the use of LED solid-state light fixtures security.
LED Ceiling housing considered as relatively simple design form, if the lamp itself using a drive that features a more focus on power conversion and LED component drivers, did not embedded microprocessor and heat treatment temperature control module, in order to avoid increasing the product raw material pieces cost, LED lamps can be integrated NTC (NegativeTemperatureCoeffient) negative temperature coefficient ThermistorSensors electricity, is the relatively high cost-effective security design.
The so-called NTC electricity, its purpose is to be set back by electronic monitoring modules LED lamps temperature, through default temperature warning or automatic processing of the corresponding driving condition, taken off the LED solid-state light source module on ways to increase the use of safety LED lamps while NTC electricity also reduces the complexity of the design.
Since the temperature coefficient of electrical NTC very large, it can detect small changes in temperature performance that is widely used measurement needs, control-related electrical design and compensate for temperature, whereas NTC electrical LED light source module design, basic Product ambient temperature changes in the measurement of solid-state LED light fixtures, as measured with the voltage situation will change in the status of NTC, directly measured the electrical voltage and NTC temperature correspondence.
When the NTC and peripheral level or raise the temperature of the entire module, NTC electrical resistance then decreases, products can be so dependent relationship feedback control mechanisms related to security, such as reducing the LED light assembly drive current or direct forced off lighting, luminaire temperature problems improve after automatic reply lighting state, thereby obtaining safety lamp used.
LED lamps can import temperature monitoring microcontroller mining SMD components manufactured in the form of NTCTHERMISTOR
Improved form of the aforementioned NTC electricity, if you want to achieve a better design, with a more sophisticated security MCU design is a relatively pragmatic approach in the development project, the status area may be divided into light LED light source module is normal, lighting It is turned off, with the temperature warning and temperature measurement of program logic to construct a more perfect wisdom lighting management mechanism.
For example, if there is a temperature warning lamp, the temperature measurement module that is still acceptable temperature range can be maintained in the normal way, through natural dissipation of heat sink operating temperature; and when the warning told the measured temperature has reached the required implementation of active cooling reference mechanism, then the MCU must control the cooling fan for moving, even when the temperature reaches the value, the system must be directly off the drive power supply through the MCU, LED components temporarily stop operating, natural heat dissipation process.
Determine whether to use the lamp on or off, using a simple judgment bit to do with the understanding of the product changes the current status, the more critical part of the temperature measurement, the temperature must be measured in real-time and reference table system for comparison to confirm the current normal or abnormal state level module calculates the temperature of the pitch, the automatic temperature control corresponding to be managed.
Similarly, when the temperature enters block, control mechanisms should immediately turn off the light source, while the system is shut down after 60 seconds or 180 seconds after the temperature again to confirm until the LED solid-state light source module temperature reaches normal, then re-driven LED light source, continue to provide illumination.