Currently in public transport use lamps are: fluorescent lamps, high pressure sodium, metal halide, LED lights. During fluorescent lamps can be used stepless dimming, but lower efficiency fluorescent light itself, along with dimming fluorescent rectifiers generally used LCC parallel resonant circuit, dimmer light resonant circuit current is still very large load, resulting in very light load power low energy saving effect is not obvious; and high-pressure sodium, metal halide dimming downs are very small, and thus the industry does not recommend the use of high-pressure sodium and metal halide lamps in stepless dimming systems; followed by the rapid development of LED current skills, LED lights gradually become the protagonist of public lighting category. Not only high-efficiency LED light source, a DC-driven, and very simple to complete stepless dimming function, so that the quality of public lighting can be improved, and to the maximum extent possible the completion of energy conservation.
LED lights dimming control There are three main forms of dimming control forms:
1) Lamp array manipulation: After the closure or lit LED lamps in a column or columns to complete the lamp brightness changes, its conditioning stages controlled by an array of lamps in several resolutions;
2) Light Group control: The address is coded lamps, and even the odd lamps or lighting fixtures complete the staggered closure, perhaps closing perhaps all lamps lit, and then complete the brightness conditioning.
3) stepless conditioning methods: From a practical lighting needs resulting reaction to changes in the LED power supply output current, then conditioning brightness LED lights;
