- The LED bulb requirement
Because of the need to replace the incandescent，so must have at least the following requirements:
The wattage is reference standard without lumens for the LED incandescent。the led luminous is Continuous to progress。The power of led does not representation of LED luminous 。the incandescent most commonly to using type has 15 watts, 30 watts, 45 watts, 60 watts, 75 WATTS and 100 watts etc。if only to discuss the led luminous，then can be calculated with the luminous efficiency of LED。The LED light efficiency of incandescent as 7.5-12lm/W。the high watts give birth to greater the LED light efficiency。correspondence of parameters between the led watts and led light efficiency, can be list as follows。
Wattage W 15 30 45 60 75 100
Incandescent Efficiency 7.5 8 8.5 9.5 10.5 12
LM 112.5 240 382.5 570 787.5 1200
LED1 Wattage W 1.56 3.3 5.3 7.9 10.9 16.6
LED2 Wattage W 1.2 2.6 4.1 6.1 8.4 12.8
led replacement lights
NOTE:Filament lamp= electric incandescent lamp
If using led replacement lights, can also draw the correspondence wattage。But the LED efficiency is continuous progress, so it is difficult to give a exact figures。Assume now commonly used LED1, the light effect is 100lm/W, if the highest light effect of the LED2, the light effect is 130lm/W (warm white light effect will be less than this value). We can draw on the two kinds of light effect LED。But because LED needs constant current source, and the constant current source has a certain efficiency, assumed to be 85%, and because LED cannot use the transparent bubble shell, but only the use of creamy white foam shell. Its light transmittance of about 85%。Multiplied by two equals 0.72。After considering the factors above. We can draw the correspondence of incandescent lamps wattage。 As shown in the table, the power LED2 can save 10 times in about the same brightness。 Have a bit need special explanation. Is from the current LED bulb lamp light efficiency and heat dissipation, it is impossible to do more than 10 watt, in other words,there is only 60-75W can replace incandescent lamp LED bulb. Of course, the PAR lamp is another matter (which will be discussed below) 。
The following basic index of LED bulb power supply:
1，Basic types of power: Mainly consists of isolated and non isolated, refers to the load part is isolated from the Firewire(AC part)。in general，no isolated not has transformer，so the cost is low, but the requirements of high pressure aluminum plate，otherwise there may be charged on the radiator。So it is not easy through the safety inspection。Isolation mode is more safe，more easily through the safety inspection, but the cost is high。
2，Power supply output power: The size must be same between LED bulb and incandescent lamp。So limited the size of radiator，at present, no more the 9W。
3, Power efficiency: In general isolated mode in about 80-85%, non isolated in about 90%。
4，Power factor(PF): about 0.5-0.6 without PF correction，Has PF correction at around 0.9-0.99
5 Size: because the bulb to the power of the space is very small, so the volume restrictions are very strict。