Research Of The Low Frequency Electrodeless Fluorescent Lamp System

The technology of high-frequency electrodeless fluorescent lamp has breaked the traditional fluorescent lamps, compact fluorescent lamp, incandescent and halogen which use the electrode to emit light. The principle is that the magnetic field excited the gas to emit light, it is an emerging interdisciplinary technology, and it is a high technology product, which generally adopt power electronics, optical, magnetic materials science, plasma science and other areas'scientific and technological achievements. The electrodeless lamp has many advantages, such as long life, high luminous efficiency, high color, no flash, can immediately start and restart, not afraid of shaking and so on, being a rookie of "green light" areas. They are widely used in indoor lighting, large areas of malls, plant lighting, street lighting, urban landscape lighting and other special venues'lighting. However, the lamp also has shortcomings: luminous efficiency is not high enough, serious electromagnetic interference, fewer species, high costs, It is of great practical significance to research and develop the electrodeless lamp lighting system which is high-performance, low-cost, reliable.At first, this paper describes the development of high-frequency discharge lamp and the application of low-frequency discharge lamp, analysis its principle and study the steady-state transformer's equivalent circuit model, introduce the principle and classification of electronic ballasts, then according to the operating characteristics of low frequency electrodeless, design a 80W electronic ballasts match with the lamp. First, as the step-critical continuous mode, peak current control mode's power factor correction control circuit is relatively simple, can achieve the advantages of zero-voltage turn-on, high power factor, so this paper uses the MC33262 chip to design an power factor correction circuit, used in the 80W low frequency electrodeless lamp's electronic ballasts, reducing harmonic interference, stabling output voltage, so that the the power factor of the whole circuit system reach up to 0.99. Second, use the external oscillating half-bridge resonant inverter as the lighting circuit, because the switch frequency is 250KHz, the circuit structure is simple and easy to control. At last analysis the electromagnetic interference sources of the entire lighting system, then design a rational EMI filter, suppress the electromagnetic interference and RF interference from the grid, and prevent the RF interference and electromagnetic interference get into the power grid from power supply itself, playing the role of two-way isolation, according with the State EMC standards.Finally, make a 80W lamp electronic ballast according to the theoretical analysis and design process previously described. It use the two-stage circuit topology as a whole circuit, including the EMI filter circuit, the MC33262 chip as the core of power factor correction circuit, NE555 together with L6384 constitute the half-bridge inverter and resonant circuits, lighting lamp, and ensure its stability work.