A high efficiency, low weight silicon controlled rectifier power supply which supplies 28V @100A is described. The power supply operates from a conventional 3 phase 120/208Vdc (50 to 1600Hz) power source. The AC power source is converted directly to DC which powers two SCR inverters operating phase displaced up to 12.5kHz. The two inverter outputs are rectified and fed into a common output filter to complete the final power conversion step. Output metering and input/output circuit breakers are provided in a rack mounted unit designed for natural convection cooling. Efficient, high frequency operation of the inverter SCR's makes possible the high overall power supply efficiency and low weight. Extremely stale and accurate voltage regulation is implemented. Additional features are inherent short circuit capability and adjustable output current limiting. Several aspects of circuit design and performance are discussed.