Design Of A New Type Dimming Fluorescent Ballast

Fluorescent lamps are used very commonly in lighting industries.Therefore, the performance and quality level of fluorescent ballasts will decide the efficiency of energy consumption of the whole lighting industries.The earlier generation fluorescent ballasts were designed with a simple construction and low performance and quality level, hence, there had being a lot of energy waste as well as a high safety risk in lighting industries. As people are putting more and more concerns on energy saving issue, it's inevitable that the popularization of ballast with high performance and quality is to be the trend.A dimming ballast is based on a high performance ballast, and dimming function is accessorial. The intention of dimming function being designed is for people to be able to adjust the output light of the lamps according to the ambient that does not require full light output. Then, energy saving is optimized, and lamp life is extended as well as that vision effect can be exchanged.This study introduces a new type of design for dimable fluorescent lamp ballast with 0-10V dimming control, and this ballast operates three T8 32W fluorescent lamps which are able to be dimmed synchronously. This design is based on the dedicated ICs—ST L6561 and ST L6574,and achieve the dimming function via a common dimming mode---frequency modulation. By optimizing the circuit design, dimming control is available for the output light level in the range of 5%～100%. In addition, the input voltage is designed to a multiple voltage range 120V～277V and make this design applicable in multiple market regions including North American, Europe and Asia.Tests and experiments were implemented on the prototypes including parametric testing, dimming fuction verification, EMI test, starting test, and abnormal condition tests. And the results met the expectation.