Nowadays LED market mixed with good and bad products makes it quite hard to distinguish quality, meantime with big price difference. Then how to judge the products and how to choose high quality product or supplier?
First, let’s analyze these from the structure of LED tube light: Light source, LED driver, profile, PCB, and PC cover.
1. LED light source:
The main brand LED chip which is first well known internationally so far is CREE, OSRAM, HP, Nichia, Lumileds. Then is Epistar, Huga, Genesis Photonics, Arima Optoelectronics(AOC), Tekcore. LED tube normally use SMD3014 or SMD3528 as light source, but now there have a new light source of SMD2835. It’s power consumption each chip is only 0. 2w, but lumens can be 22-24lm/pcs. In theory can reach 110lm per watt, also have great advantage with other chips in color and low light failure of no more than 1% after 2000hrs.
2. LED driver:
LED driver can be divided into constant current and constant voltage, non-isolated and isolated.
a. Constant current driver: when voltage is not stable, but the current for LED is constant. This can protect LED’s longer life span.
b. Not constant current driver: this also is resistance capacity driver used for low quality products nowadays. It adopt the most simple and old method to reduce voltage. When voltage is not stable, current will also change, that will bring quality problem in high rate. There has a method to distinguish constant current and not constant current: open the photograph mode of mobile or camera, if the photo flickers like TV screen that is not constant current. If the light is stable no flicker then can be constant current.
c. Non-isolated driver: this means driver load side connect directly to input side, so if human touch the load side without intention there will have dangerous of getting electric shock. This driver has advantage in cost because it has simple circuit design.
d. Isolated driver: this driver have transformer between input side and load side. The production cost is higher compared with non-isolated driver, but efficiency of driver will be lower and size little bigger.
3. Profile:
There have 2 kinds of profile in market now. One is all plastic type, the other is half plastic half Alumium type (2/3 plastic, 1/3 Al);
a. All plastic type is adopted mainly in early time, as most of driver used is non-isolated driver. To avoid dangerous of getting electric shock, so mostly use plastic profile. But this have big problem of heat dissipation, all heat is sealed off in plastic tube. Heat dissipation is the most important factor for LEDs, if can’t dissipate heat well, then will have high light failure and low life span. And the DIP have low life span itself, it can’t be use after 2000hrs.
b. Half plastic half alumium tube: this type is most popular in market. Adopt PC on the light transmitting side, the other side is Alumium. And put the driver in the Alumium profile, this allows much heat can go out. Now most tube have power consumption of below 20w, if have higher power, this half Alumium profile may can’t solve this heat dissipation problem.
4. Other:
a. End cap: there have different kinds of end cap such as material of Alumium, PC, and Alumium with PC. Divided by fix method there have fix by glue, by screw. In terms of safety and environmental protection, fix by screws can be acceptable more easily and also now most popular in market.
b. Light transmittance: normally clear PC cover can have transmittance of 88—95%, milky white cover have 70—86%. If the naked lumens of one 20w tube is 2000lm, after assemble with a transmittance of 88% PC cover，then will have only 1760lm. If assemble with 95% transmittance PC cover then will have 1900lm. But clear PC cover have a disadvantage is the light dazzling a lot. It much more soft if make with milky white PC cover. To use which type depend on the environment of application.
c. PCB: Stick LED chip in some pattern on PCB or Aluminum electronic circuit board, and then fix it on Alumium radiator. Glass fiber’ heat conductivity coefficient 20w/mk, Alumium alloy is 200w/mk. The coefficient higher, the better is the dissipation effect.
d. Life span: The life span of LED chip depend on well Collocation of LED, driver, heat dissipation. Except this 3 factors, another basically parameter is light efficiency. The high light efficiency, the better the tube is.
As a leading manufacturer of LED lights, EMIT International Group has enjoyed great reputation in quality control and aftersales service. When choose LED lights, should pay more attention on material, technology, and credit of the supplier.
Company Name: ECVV Technology Development Ltd.
Contact Person: Alice He
Email:Send Email
Phone: +86 731 89824048
Address:Rm. 407, Software Bldg., No.662 Lugu Road
City: Changsha
State: Hunan Province
Country: China
Website: http://www.ecvv.com
0 comments:
Post a Comment