中文摘要：

为了满足铁路信号灯系统要求发光二极管（LED）照明电源在恶劣环境下具有转换效率高，使用寿命长，稳定性好等特殊性能，对大功率LED在铁路信号灯应用中的部分特殊性进行了分析；设计了一种可与原有铁路变换器兼容的高效功率铁路LED信号灯恒压Buck转换器及恒流驱动电路。实验结果表明，电路可以达到预定的设计指标。

英文摘要：

The Light Emitting Diode（LED） working at abominable environment was required to have the characters of high conversion efficiency, long lifetime and good stability and so on, in order to meet the demands of railway signal lamp. The particularities of power LED applied to railway signal lamp are analyzed, an effective Buck controller,which is compatible with original railway signal technology,and a drive circuit of constant current system were designed. Experimental result verifies the new designed system achieves the expectation.