一种新型低成本高可靠性金卤灯启动电路

金卤灯因其声谐振现象比较严重,通常采用低频方波驱动来彻底消除声谐振,附加点火电路。相对于高频谐振点火方式,这种适用于低频方波的附加脉冲式点火电路需要比较多的元件数,既增加了复杂性,也因引入了火花隙、晶闸管等一些开关器件,使整个电路的可靠性大大降低。本文提出了一种新型的启动电路。它不含开关和反馈控制电路,利用全桥输出方波电压正负跳变时的少量高频分量,通过谐振放大后产生点火所需的高电压和点火电压的位置,同时保证了灯启动后电弧的稳定,当灯工作于稳态时,点火电路对灯并无影响。理论分析和一个70W金卤灯的实验结果同时验证了该电路的有效性。

Novel Low-cost High Reliable Igniter for Metal Halide Lamps

Metal Halide lamps have very serious acoustic resonance problems,the most widely used method to achieve free acoustic-resonance is low-frequency square-wave electronic ballast with an additional pulse igniter.Compared with high-frequency resonance ignition,the auxiliary pulse igniter needs more components which add to the complexity,it also includes some element such as Sidac,Thyristor,Diac and so on which decrease the reliability of the igniter.The paper proposes a novel igniter which does not need any switch and feedback control circuit.By using the high-frequency components of the output voltage of the full-Bridge inverter,a high-ignition voltage can be obtained by a resonance circuit.The location of the ignition pulse also ensures the arc stability after ignition.The theoretical analysis and the experiment of a prototype for 70W MH lamps both verified the effectiveness of the igniter.