Why LED Downlight does not need to have a ballast
Gas discharge lamps with negative resistance characteristics, such as fluorescent lamps, sodium lamps, mercury lamps, etc., only need to use ballasts. Ballasts provide two main functions: high-voltage triggering and current limiting.
LED Downlight is a low-voltage DC power supply, no high-voltage trigger, and therefore does not require inductive components as ballast. Of course, LED lamp beads can not be directly connected to the ordinary AC mains, need a special power supply to complete the buck, rectification, current limiting function.
LED Downlight comes with a constant current source, no ballast, glow starter. General T8 or more lamps because the lamp space is large enough, constant current source can be installed inside the lamp.
Advantages of LED Downlight
(1) Energy saving. Fluorescent
Lamp electronic ballast, more than the use of 20 ~ 60kHz frequency supply lamp, so that the lamp luminous efficiency than the frequency of about 10% (according to the length of 4 feet of the lamp), and their own low power consumption, so that the total input power of the lamp decreased by about 20%, with better energy-saving effect.
(2) Eliminates strobe, more stable luminescence. Favorable to improve the visual resolution, improve the efficacy; reduce the visual fatigue of continuous operation, conducive to the protection of vision.
(3) The starting point is more reliable. Preheat the lamp after a successful starting point, avoiding multiple starting points.
(4) High power factor. Meet the national standard of more than 25W fluorescent lamps, the power factor is higher than 0.95. But it should be noted that the national standard for 25W lamps below the specified harmonic limit is very high, in order to cause its power factor dropped to 0.7 ~ 0.8.
(5) stable input power and output luminous flux: high-quality products have good voltage regulation performance, in the power supply, voltage deviation is very large, but still maintain the light source constant power, stable luminosity, conducive to energy saving.
(6) extend the life of the lamp. High-quality products of constant power and lamp current drop, as well as the starting point of reliable and other factors can make the lamp life longer.
(7) Low noise. High-quality electronic ballast noise up to 35db or less, people can not feel the noise.
(8) LED Downlight can be dimmable. For places that need dimming, such as: the original use of incandescent or tungsten halogen lamp dimming places, replaced by high-efficiency fluorescent lamps with dimmable electronic ballasts, can achieve a wide range of dimming in 2% to 100%.