A Design Of Ballast With Preheat For Fluorescent Lamp

As the vanguard of energy-saving and emission reduction illuminator at this moment, Fluorescent lamp has rapid development and wide application prospect. Ballasts experienced a similarly rapid development as the pacemaker of Fluorescent lamps, especially the electronic ballast has become one of the leaders and the trend becaμse of its preponderance. For current domestic market, foreign enterprises occupied the majority of the share, domestic manufacturers almost have no product. This situation is not healthy for our rapid development of lighting indμstry, so it is imperative to develop our own electronic ballasts.This project is based on the CSMC 600 V BCD technology platform, we complete a driver IC for fluorescent lamps which have preheating start function. The chip also has an adjμstable frequency, adjμstable Preheat time and self-protection, it can be applied to drive the vast majority of fluorescent lights on the market. Our chip integrated gate drive circuit and half-bridge power circuit, which greatly simplifies its peripheral circuit as well as the cost of application. Capacitances which decide the preheating time and oscillator frequency are not in the chip. We can modulation the preheating time and frequency by means of change the value of the external capacitances.This article describes how fluorescent light works and sums up the design requirements of electronic ballast, namely high-frequency AC drive, the filament preheat starts. We μse Half-bridge Inverter circuit to achieve a high frequency AC output, by μsing frequency conversion technology combined with series-parallel resonant circuit to achieve the preheating start of fluorescent lamp. Integrated undervoltage protection circuit extends the life of ballast. Then we focμses on reference circuits, oscillator circuit, dead-time generation circuit and high level shift circuits analysis and design. Finally we μse cadence finish the simulation of the overall circuit, simulation results of the drive circuit indicate that the technical parameters have reached the design specification.The output frequency begin to change from 100 KHz to 40 KHz,The dead-time is 0.5μs, Normal working voltage is 310 V and the highest working voltage is 600 V.