How to increase the lumen on led headlight bulbs the lumen output of led headlight lights? This question is highly recommended everyday by manufacturers. We all wish to offer clients the brightest led headlight package with best light beam. But how do we achieve that? What technical problem now do we meet? Here please let me explain to you.
Select top quality LED Chip for light source if you want to produce continuous high Iumen LED headlight bulb, which have to be high relative Iuminious flux and temperature resistance. The initial choices are well-known LED suppliers Iike Philips Lumileds, 0sram, Cree, Nichia, Sámsung and so forth. Their LEDs have excellent performance and work very well at high temperature.
Efficient cooling technology can increase lumen result and extending LED lifestyle. The energy conversion price is fixed. Aróund 35% energy converts to light, 65% energy converts to heat. We can’t boost energy conversion rate.
And for LEDs, their Relative Luminious Flux vs. Junction Temperatures is fixed too. Lumen shall reduce when junction temperature rises. (The chart of Luminious Flux vs. Junction Temperature of Cree XHP50 below)
Under a specific condition, 12V Voltage, ahead current will decrease as ambient temperature goes up also. When forwards current on LEDs falls, Lumen decrease aswell. (The chart of Optimum Current vs. Ambient Heat range of Cree XHP50 below)
That means if we want to increase Luminious Flux, we need to control ambient temperatures at within a reasonable range. Heat produced from LEDs at the job. Heat dissipation may be the key point.
Except led chip, other consumer electronics of led headlight bulb will produce heat at work also, like IC driver, capacitance and so on. These consumer electronics themselves could rise the ambient heat range to 70 -80℃, if they’re built-in led bulb, the heat from LEDs and consumer electronics will mixed and accumulate, temperature goes up too high. Now the reliable design is to produce a driver on outsidé built-in thése electronics. Then we only need to think about how to reduce the ambient heat range of LEDs
>There are two cooling methods for LED headlight bulb, First one is active cooling; second is normally passive cooling.
>Active Cooling Techonology Active cooling identifies dissipate héat by héat sink to attain thermal balance. The heat conduction process is really as follows; Heat created from LEDs at work → PCB board → Bulb light weight aluminum body→ Aluminum heat sink, Each high temperature conduction process concerns on a production technol
First, soldering, it has a great impact on the lifetime of LEDs. Heat produced from LED at function, if you want to transfer temperature to PCB table and fast sufficiently, soldering needs to be professional and accurate. We have to Select high quality LED Chip for light source high quality solder paste, professional soldering SMT and machine equipment to make LED be soldered very well. If choosing inexpensive solder paste, ór soldering LED by hand and simple equipment, you will see bubble space between LEDs and PCB board, the linking between two surfaces isn’t fully complete. I mean some areas between two surfaces aren’t connected well. Heat on these aréas couldn’t transfér and will keep gathering, temperature on LED up will go, LEDs are working continuously under temperature, as I above mentioned, LED Luminous Flux will end up being reduced, life will be shorted. Good soldering technology could decrease unconnected area to the very least and makes LEDs transfer warmth to PCB board sufficiently and unifor
Secondly, Heat transfer from LED to PCB board and can continue transferring to bulb body. On this process, PCB board plays a major role. The very best PCB panel is copper foundation PCB, as the thermal conductivity of copper may be the best. Aluminum foundation is accompanied by, the worst is glass-fiber table. The top of PCB board ought to be as simple as possible for reducing the gap between PCB plank and bulb b
In addition, we will use heat transfer silicone to fill in the gap between PCB plank and bulb body, increase heat transferring. Cheap and good heat transfer silicone will vary widely. Like CPU heat transfer silicone just, you guys ought to know t
Next, heat will travel to warmth sink and dissipate gradually. If bulb high temperature and body sink are integrated, heat will transfer quicker and fluently. But, it needs die-casting strategy to make two metallic parts integrated. Some metals aren’t permitted to die-casting. Copper can, it really is good, but expensive and heavy. We use light weight aluminum for warmth sink normally. Pure aluminum provides high thermal conductivity, but is definitely too smooth to be processed by die-cásting technology. The light weight aluminum alloy for die-casting is certainly low thermal conductivity, not really designed to be warmth sink. The best solution for car headlight warmth sink is 6063 aluminium alloy, which is tough, high thermal conductiv
But 6063 lightweight aluminum alloy can’t be processed by dié-casting technology; factories usually joint 6063 aluminum high temperature sink and light bulb body together by screw alloy, rivet, or hydraulic machine. There is another well-known solution to combine them by thread, in this way, mould requires being precis
The form of heat sink will affect heat dissipation performance. A larger surface of heat sink will promote high temperature loss. Besides, airflow should be taken into factor. The area between cooling fins is not allowed to be too narrow, or temperature won’t dissipaté fast but transfér to various other cooling fins. Here we take a example, the Ebay led headlight below, there are so many cooling fins on high temperature sink and they are extremely closed, space bétween fins are narrów, that is not good for heat dissipation. In comparison, you can see the Philips led headlight was designed a little fins on heat sink, but théir fins gap aré spacious for airfIow, heat dissipation functionality will be bet
If big heat sink with large surface area is better for high temperature dissipation, why dón’t we help to make all led headlights with big warmth sink? That is because there is limited space behind headlight casing in a few vehicles. Halogen lights are small size while led headlight is definitely big size, when it’s replaced by us with a led headlight bulbs, space behind headlight housing is not enough in order that LED headlight may’t be installed on sometimes. So in practice, we are in need of the heat sink no more than possi
What??? Yes, this is correct; warmth sink can’t be made too large for avoiding installation problem. But if wé make led headIight to be higher Luminous Flux, the ahead current on LEDs will and high temperature will be produced more. So heat dissipation problem limits the cap óf Luminous Flux óf led headlig
Passive Cooling TechonoIogy, so except active cooling, factories also present another solution for heat dissipation, passive cooling, that is to equip a fan about led headlight buIb, cooling the buIb by fan. Thé passive cooling technique is simpler and more straightforward. And we can make led headlight bulb end up being small size in addition to high lumen result in this met
But it is a doubIe-edged sword to set up a enthusiast on led headlight light bulb. Heat dissipation is relying on fan. If lover has quickly short lifespan and stop running, led headlight light bulb will blow in soon. Therefore the quality is vital. We generally make use of two types of fans now, sleeve bearing enthusiasts and ball bearing enthusi
Sleeve bearing fan relies on lubricating oil to work. It really is low manufacturing price, and operates fast with low sound at the beginning. After working for a while, lubricating essential oil will volatilize, fan rotating speed will also drop significantly. Climate and working condition decide the lifespan óf a sleeve béaring fan, normally it can work six months to 12 weeks on a car led headli
Ball bearing fan is much better though generally more costly. Predicated on the rolling friction transmission and consisted of two ball bearings, there are a few tiny metal balls in thé bearing, balls change when their axis movements with little friction. Ball bearing enthusiasts usually do not suffer the same restrictions of oil volatilizing as sleeve bearing enthusiasts, are stronger at higher temperatures, and has longer lifes
Beside, for better warmth dissipation, the airflow direction of fan should be the same to the airflow direction of heat stability. Some manufacturer violates this principle to design their product for a good-looking appearance; heat dissipation performance is suck finally. You can see that Philips LED headlight don’t possess any cover on air flow inlet. Fan will continue to work hard while warmth dissipation performance will be gr
Finally, it’s the driver. When driver is certainly put on outside, we don’t need to worry that it will transfer heat to bulb and have an effect on the luminous efficacy of LEDs. But we have to care about what electronic inside the driver. And is output current reasonable? Is forward current on LEDs stable? Is there temperature control device in driver? They will all decide the final quality, lifespan, lumen output of a led headlight bu
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