There are so many led tubes manufacturers in China now. However, their quality and performance has much difference. the foreign trade enterprises, energy saving companies, engineering companies, foreign companies procurement office
in China and other non -professional personnel do not know how to distinguish the quality and performance of LED tubes
from each manufacturer while purchasing products. As a result , they don't know how to choose and purchase led tubes .
they may spend a high price and do not get the ideal product you want. You should consider the following aspects while
you choose and purchase led tubes : pro
1 . The pro
(1) Diameter: What does T mean ?
T5: 5/8*1inch(25.4mm)=16mm
T8: 8/8*1inch(25.4mm)=25.4mm
T10: 10/8*1inch(25.4mm)=31.8mm .......
Length: 600mm(2ft) , 900mm(3ft), 1200mm(4ft) , 1500mm(5ft) , 1800mm(6ft), 2400mm(8ft)
(2) There are two kinds profiles for LED tubes on the market now : PC( Polycarbonate) and aluminum(1/2)+PC (1/2) .
Please refer to the following photos:
Please refer to the following photos:
PC LED Tubes
What is PC? How many type of PC used for LED tube?
PC is Polycarbonate, there are four types of PC for led tube: striped PC , semitransparent , transparent PC , frosted PC .
transmittance: transparent PC> striped PC>semitransparent PC>frosted PC
PC LED tube: LED tube produced early is used is PC LED tubes, because mainly adopts non-isolated power, in order to avoid electric shock, so use PC tube. Adopt φ5mm straw LED as light source . The biggest problem of this kind of led tube is the heat problem. because the heat all sealed in the tube, unable to escape, attenuation is very serious, plus the life of straw led is very short, they will dead less than 2000 hours.
Alumimum alloy(1/2)+PC(1/2) LED tubes
Most of led tubes on the market are aluminum alloy(1/2)+PC(1/2) LED tubes, a half use PC ( where light comes from) and another half use aluminum alloy . The power supply are placed in led tubes of course . Thus, the heat of LED and power supply is considerably large. because the power of the lamp is usually around 20W. Half aluminum tubes can not solve the heat problem when the power is much larger. So another heat dissipation aluminum tube structure appears: the frame shape tube. This frame alumimm led tube adopt frame Radiating structure , greatly increasing the area of the radiator. Power supplys are placed outside of the tube, which can put half the aluminum shell is completely made of radiator. Compared with the semicircular tubes, the radiating area is increased at least 3 times. Coupled with the power supply is not placed in the tube, which can reduce the heat and greatly extend the life of LED.
2. Power supply
There are two kinds of power supply : built-in and external type . The built-in power supply can be placed in the inner of the
tube. The biggest advantage of the built-in led tube is to directly replace the existing fluorescent tube, without changing any
circuit. So the built-in power supply are liner shapes so that they are elongated into semicircular tube .
tube. The biggest advantage of the built-in led tube is to directly replace the existing fluorescent tube, without changing any
circuit. So the built-in power supply are liner shapes so that they are elongated into semicircular tube .
1) non-isolated constant-current source: non isolation refers to the load terminal and the input terminal is directly connected,
therefore touch load will result in dangerous electric shock . The advantages of non-isolated constant supply is the circuit
design simple, the manufacturing cost is not high. Disadvantage is that the high voltage AC power supply into the load,
resulting in the risk of electric shock.
therefore touch load will result in dangerous electric shock . The advantages of non-isolated constant supply is the circuit
design simple, the manufacturing cost is not high. Disadvantage is that the high voltage AC power supply into the load,
resulting in the risk of electric shock.
2) isolation constant current power supply: isolation type refers to isolation transformer at the input end and the output end.
But all the input and output isolation. The advantages of isolation constant-current source circuit design is a complex, can
avoid the danger of electric shock. The efficiency of the power will be reduced, the manufacturing cost is high, the volume is
relatively large, It can be put into the T10 tube , but put into the T8 is more intense.
But all the input and output isolation. The advantages of isolation constant-current source circuit design is a complex, can
avoid the danger of electric shock. The efficiency of the power will be reduced, the manufacturing cost is high, the volume is
relatively large, It can be put into the T10 tube , but put into the T8 is more intense.
3) centralized external power supply: you had better use centralized external power supply to get the maximum performance .
Because the main promotion place of LED tubes is the government agency, office, shopping malls, schools, underground
parking, subway and other places. more than on
centralized external power supply . The so-called centralized refers to use a large power unified AC/DC switching power
supply, and each LED tube adopt separate DC/DC constant current module. So that you can get the highest power efficiency
and the biggest power factor . The advantages of centralized power supply is obviouse. Moreover, it is an isolated power
supply, this structure is also very easy to implement various dimming schemes.
Because the main promotion place of LED tubes is the government agency, office, shopping malls, schools, underground
parking, subway and other places. more than on
centralized external power supply . The so-called centralized refers to use a large power unified AC/DC switching power
supply, and each LED tube adopt separate DC/DC constant current module. So that you can get the highest power efficiency
and the biggest power factor . The advantages of centralized power supply is obviouse. Moreover, it is an isolated power
supply, this structure is also very easy to implement various dimming schemes.
3. chip : there is nothing to say for chips, under normal circumstances, the first class brand chips , such as CREE, Osram,
HP (HP), Nichia chemical (Nichia), Toyota synthesis of Lumiledss, their quality must be more better than the second class
chips from Taiwan. Currently led used for LED tubes is 3528, 3020, 3014 and other specifications, the specification is different on chip size and the cooling method. The same brand of chip, packed by different manufacturers , the quality is not
the same.
HP (HP), Nichia chemical (Nichia), Toyota synthesis of Lumiledss, their quality must be more better than the second class
chips from Taiwan. Currently led used for LED tubes is 3528, 3020, 3014 and other specifications, the specification is different on chip size and the cooling method. The same brand of chip, packed by different manufacturers , the quality is not
the same.
4. other
power protection sleeve: built-in power supply is placed in the aluminum alloy radiator, it must have a way with its insulation,
or it will cause leakage. External power supply is not the existence of such phenomenon. There are three ways on the market
at present.
or it will cause leakage. External power supply is not the existence of such phenomenon. There are three ways on the market
at present.
1) insulation sheet, The power is wraped around by a insulation paper , and then put into the aluminum alloy radiator. The
disadvantage of this approach: in the operation of the power into the aluminum alloy radiator , the insulating paper is easy
to be cut by aluminum alloy corners ; The power is very easy to move in the aluminum alloy tube because nothing is fixed on
two ends .
disadvantage of this approach: in the operation of the power into the aluminum alloy radiator , the insulating paper is easy
to be cut by aluminum alloy corners ; The power is very easy to move in the aluminum alloy tube because nothing is fixed on
two ends .
2) heat-shrinkable tube, is a kind PC material, which will tighten when come cross heat. The power supply is cased with a
heat-shrinkable tube outside , and then use hot wind blowing, so that the heat shrinkable tube close to power pack inside, to
achieve the insulation purpose. Disadvantages: heat shrinkable tube and electrical components on the power supply are closely together. thermal power emission can not dispersed, As a result, the life time of power supply is shorted .
heat-shrinkable tube outside , and then use hot wind blowing, so that the heat shrinkable tube close to power pack inside, to
achieve the insulation purpose. Disadvantages: heat shrinkable tube and electrical components on the power supply are closely together. thermal power emission can not dispersed, As a result, the life time of power supply is shorted .
The insulation box, which is a customized insulated box according to the size of the power , it has radiating holes, fixing piece,
the best insulation at present.
the best insulation at present.
2) a fixed end: At present a lot of joint mode on the market: aluminum skin, PC material, aluminum cover and PC material .
Two ends of led tubes are fixed with glue or screws according to the fixing method . LED tubes fixed by screws is widely used by consumers because it is safe and environmental
Two ends of led tubes are fixed with glue or screws according to the fixing method . LED tubes fixed by screws is widely used by consumers because it is safe and environmental
3) the transmittance of PC : the transmittance of transparent PC can reach 88 - 95%, the the transmittance of frosted PC can
reach 70-86%. The luminous flux for a led tube without PC cover is 2000lm, now cover it with a transparent PC whose transmit
tance is on
the actual luminous flux is 1900lm, They are the same transparent PC, why do they have such big difference between them?
The answer lies in PC material. There are ordinary PC material, optical PC material on the market at present . the difference
of light transmittance is considerable because manufacturers are not the same.
reach 70-86%. The luminous flux for a led tube without PC cover is 2000lm, now cover it with a transparent PC whose transmit
tance is on
the actual luminous flux is 1900lm, They are the same transparent PC, why do they have such big difference between them?
The answer lies in PC material. There are ordinary PC material, optical PC material on the market at present . the difference
of light transmittance is considerable because manufacturers are not the same.
4) the substrate: at present LEDs are mounted to PCB or aluminum base electronic circuit board, and then fixed on the
aluminum alloy radiator through a certain arrangement . The thermal conductivity of PCB is 20w/mk, The thermal conductivity
of aluminum alloy is 200w/mk. Thermal conductivity is higher, the heat conduction effect is better.
aluminum alloy radiator through a certain arrangement . The thermal conductivity of PCB is 20w/mk, The thermal conductivity
of aluminum alloy is 200w/mk. Thermal conductivity is higher, the heat conduction effect is better.
5) Life: the lamp life time span, is mainly depended on chips, chip package, power supply, heat and other aspects reasonable
match, but these non professionals who do not understand the are still very difficult to make a choice. In the final analysis, except the most basic materials, there is on
match, but these non professionals who do not understand the are still very difficult to make a choice. In the final analysis, except the most basic materials, there is on
