In order to satisfy the requirement of solar irradiance spectrometer spectral calibration on the satellite, a mercury-lamp source is designed based on its characteristics which can be described as high voltage to glow and low voltage for work. The single-ended fly-back topological structure and four level dual voltage rectifier are used to provide the high glowing voltage. And the degenerative feedback is designed to current constant. The glowing voltage and working voltage can be switched automatically wit...