User talk:Hhlight.led

LED BULB Component. A. Light Crust. Involved the PC and Glass crust. Heat conduction silica gel is the gel pasted between the MCPCB and the Al radiator,the heat conductive of the best is 2.5-2.6, and the worst is 0.5-0.6One piece of silica gel can used for 1000 pieces led light. Noted: The heat conductive of good conduct is 2.1-2.3

PC crust. Advantage: a.Press-resistance and shatter-resistance, b.the light tramsmittance can be changed,when the fluorescent powder is different, c.No pollution,the pc crust can have multi-shape for your special requirement. Noted: The crust of good product is clip on the al radiator, no glun, so no yellow colors on the rip of the crust when the light used for long period. And the crust never drop off.

Disadvantage: The light transmittance is lower than glass crust, about 65-75% for ordinary crust. But as the development of the technology, high light transmittance crust have come out. Using novelty composite materials, the light transmittance for white crust can reach to 90%. Noted: Using the imported PC crust, the light transmittance or our product can reach to 90%. You can compare two parameters, one is the lumens without crust, the other is the lumens with crust. Then you can get the confirmations.

Glass crust. Advantage: a.Higher light transmittance,about 85-95% b.The color is restored well when through the crust. Disadvantage:a.Fragil,no safety for user. b.The inner surface of the crust will come out the droplet when big temperature ranges.

B. Radiator There are four types of radiator in the current market, die-cast aluninium, extrude aluminum, plastic and pottery.

I)Die-cast Aluminium. Advantage: Low cost, Easy to install, very suitable for mass production,small error between the products, high rigidity. Disadvantage: Low heat emission, about half of the Extrude aluminium for this parameter,bad look, Always need the oxidation treatment or blast sanding. Low extensibility.

II)Extrude Aluminium Advantage:a.High heat emission. About two times than die-cast aluminium. b.High Extensibility,can be processed to multi-shape easily. Noted: The material of good product is 6063 or 6068 Aluminium, the purity of the aluminium is more than 92%. Disadvantage: High cost.

III)Plastic Advantage: This material is the trend in the coming days.Low cost,installed easily,and suitable for mass production. Disadvantage: Low heat emission.

IV)Pottery: Advantage: High heat emission, between the extrude aluminimu and the die-cast aluminimu,low fees for new shape model, Disadvantage: Fragile, Heavy.

C. Light sources. Four types as usual, low-power led,high-power led,area light and COB.

I)	Low-power led(<0.5w): Advantage: a.Uniform light            b.high light efficiency, about 90lm/W,high heat emission.

Disadvantage:a.Lumens depreciation quickly b.Easy to damage. There are many leds in one light, if any one led is damaged, the light will be damaged. The chips size in this led is very small, very easy to be breakdown by Electrostatic,and so on.

II)High-power led(>0.5w): Difficult for uniform light,low lumens depreciation, not easy to damage.For this advantage, determined by the chips in the led,to a great extent.For more informations,please noted the led chips in the below.

III)Area Light: Low heat emission,uniform light.

IV)COB: The full name of the COB is Chips is encapsulated on the MCPCB directly. Advantage: a.	High heat emission. The heat is disffused from MCPCB directly.No other accessories of the bulb. So the speed for heat emission is very fast.About 1.5-1.8 times than ordinary leds.

b.	Low cost. The material for COB is MCPCB,LED chips. No others extra materials.

Disadvantage. Difficult to manufacture. The six chips should encapsulated on the mcpcb at the same time. If the technology is not good,maybe one or two of them is not work when link to the electricity.

V) LED chips. LED chips is the key factory for led light. Two typs led chips if classified by shape, one is square chips, the other is round chips.The price of square chips is a little higher than round chips.

We oftern classfied by brandmark.

First class chips: Cree chips, Nichia chips. Advantage:a.The lumens depreciation is low, 0% for the first 3000 hours. b.The light efficiency is very high,110-130lm for 1w. Maybe 200lm/w have come out in their lab.the character is very steady in the whole lifespan. c. The input current can reach to 700-850mA for 38x38mil chips. Disadvantage:The price is very high.

Second class chip: Bridgelux chips,Edison Leds,Semiled chips,Epistar chips,CMO chips and so on. The character and price of these chips is between the first class chips and the third class chips. This is the main chips we use.Usually Bridgelux chips and Edison led for high power led,and Epistar chips,CMO chips for small power led.

The lumens of chips determined by the input current and chips size. If the input current and chips size is larger,the output lumens will be more,and at the same time,the heat is also more,and the heat should emission quickly. If not, the lumens depreciation will be fast and the lifespan of led is short. From the junction temperature (the max temperature of the light surface),we can confirm this character. And this data is no more than 65℃ is good.

Common parameter for light sources. Light sources	Input current(mA)	Chip size(mil)	Output lumens(lm) 1W led	           350	                 38x38;45x45	 85-95 2W led	   500 	           45x45	 120-130 3W led	   750	                   45x45	 160-180 5050 SMD	   60	              9x21;13x15;8x20	 18-21

VI)LED driver. Usually three types on the current market: Constant current source, constant voltage sources and R-C led driver.

Constant voltage sources Usually used for small power led light, and the total number is not confirmed.The output voltage is constant.

Constant current sources. Usually used for high power led light, and the number is confirmed.The output lumens don’t changed when the outer current is changed.That confirmed the output lumens is constant and the steady of the led chips.

R-C led driver. Low cost, but the character is not steady. The special advantage of our led drivers: