Urban lighting has played a positive role in improving urban living environment, improving the overall quality of the city, promoting domestic demand, and stimulating the city's nighttime economy, and has made great contributions to the city's social, environmental and economic benefits. At present, the annual electricity consumption of urban lighting (referred to as the collective name of landscape lighting and functional lighting) accounts for about 4-5% of the total power generation in the country. Urban lighting power saving is of great significance. Ordinary energy-saving lamps have a short life span, resulting in power saving without saving money. Semi -conductor lighting is an important development direction in the future of lighting. Compared with energy-saving light bulbs used in general photovoltaic power sources, semiconductor lighting has many advantages such as energy saving, longevity, safety, environmental protection, rich color, small size, flicker resistance, high reliability, and convenient control. As a new type of illumination source, LEDs are gaining more and more applications.
First, the characteristics of semiconductor lighting
Semiconductor light-emitting diodes are commonly used in electronic component diodes. A light-emitting diode (Light Emitting Diode, abbreviated as LED ) is a device that converts electrical energy into light energy and is a solid-state light source. The LED is a semiconductor device that realizes electro-optical conversion through a PN junction, and has the following characteristics:
(1) Long life and fast response
In general, the life of an ordinary incandescent lamp is about 1000h, the life of a fluorescent lamp is about 10000h, and the life of an LED can reach 2-100,000h, and the life is much longer. The corresponding illumination of the LED is fast, its corresponding time is nanosecond, the fluorescent lamp is 0.1ms, and the fluorescent lamp is generally millisecond.
(2) Small size and firm structure
LED is a solid-state light source encapsulated with epoxy resin. Its structure is neither like incandescent lamps with fragile components such as glass bubbles and filaments, nor is it a large-volume lamp and accessories like fluorescent lamps. It is an all-solid structure, so it can It can withstand vibration, shock and damage, and the volume is relatively reduced, the weight is light, and the cost is low. In summary, LED is a light source that meets the requirements of green lighting.
( 3) Safety, energy saving, and no environmental pollution
The light-emitting diode has a low forward working voltage of (1.5-3.0) V and a small operating current of (5-150) MA, thereby achieving good work safety. In the process of LED illumination, only a small part of the electrical energy becomes thermal energy, and most of it becomes light energy. The semiconductor lamp uses LED as a new light source. When it is kept at the same brightness as ordinary incandescent lamps, its power consumption is only after One tenth of the person, so the energy consumption is small. As technology advances, it will become a new type of lighting source. At present, the luminous efficacy of white LED has reached 401m/W, which is better than incandescent lamp, and is second to fluorescent lamp (60lm/w~200lm/W). In addition, the incandescent lamp used now emits too much heat to affect the ambient temperature; and widely used fluorescent lamps, mercury lamps and the like contain mercury which is harmful to human health. In this way, the illuminating process and the discarded lamps can cause harm to the human health and the environment. LEDs do not have these problems and are a pollution-free light source.
Second, the main function and structure of the control circuit
The main functions to be realized by the control circuit are: first, through the control, to achieve the energy transfer, it is required to ensure that the driving pulse width of the two transistors is high, so that the positive and negative average magnetic fluxes are equal, and no biasing occurs; To limit the pulse width, it is necessary to soft start, so that the pulse width rises slowly in the first few cycles of starting; prevent straight through; the second input is isolated from the output; the third output voltage is stable; the overcurrent protection of the fourth circuit;
Ultraviolet Lamp,Pll Uvc Tube,Pll Uvc Light,Pll Uvc Bulb
Changxing leboom lighting product CO.Ltd. , http://www.leboomuv.com