Self-protection, Electronic Ballast Frequency Analysis And Spic

As an important energy-saving production, the high-frequency electronic ballast is more and more attracted in many countries. Many International states have made fluorescent lamp ballast using Smart Power Integrated Circuit.(SPIC), such as IR corp.'s IR215X series productions. The advantage of SPIC is high-reliability, but the high-cost will be a bottleneck to progress. In our project, we use the patent of XingBi Chen, not using the method of medium insulation or pn junction insulation (that is not using international BCD technology). We use the method to make high-voltage (power) device and low-voltage CMOS circuit or BiCMOS circuit in a chip, which makes the cost of SPIC falling.In this paper, we have deeply researched soft-startup electronic ballast. The soft-startup is that we use a larger by larger current to preheat the filament to avoid the current striking to filament and extent the lamp's life. The primary work is: have analyzed detailed in frequency-varied electronic ballast's soft prompting characteristic and preheating start-up characteristic, which would make reader to understand the frequency-varied electronic ballast's working principle, and have described a method about how to design the output LCR circuit parameter; Have designed the protection circuit in the electronic ballast SPIC, and analyzed the abnormal states protection. In the protection circuit, we emphasize the over-current protection circuit in different stages, and the over-temperature protection circuit, low-voltage source's over-voltage, under-voltage protect, and so on, which would improve the reliability; Have provided several design method for 6V low-voltage source with analyzing in detail; Have improved a new CMOS square wave oscillator circuit for the preheating fluorescent lamp with low-cost and good-performance. The circuit can afford the different stages of fluorescent lamp, i.e., the stages of preheating, igniting, and running frequency condition, and also easily extend in the other fields, which need the power supply frequency changing with time.In last, we have designed the whole circuit's layout, checked the layout and production in the 58 Institute. Through analyzing the testing result, we sum up the experience in our work.