Abstract: A computer server rack for mechanically supporting and electrically powering computer servers is provided. The rack includes DC-to-DC conversion circuits which are configured to convert a relatively high DC facility voltage (e.g. 380 volts DC provided throughout a data center on busways and/or appropriate wiring) to DC voltage useable directly by a computer server (e.g. 12 volts DC). The conversion circuits are highly efficient and convert substantially all of power input to the circuits at the input voltage and input DC current to a high DC output current at a lower output voltage.

Abstract: Improved electrical power conversion system configured to transfer power between a DC voltage differential occurring between input DC terminals and lower DC voltage differential made up of the output differential voltages between a positive output DC terminal and a system neutral terminal and a negative output DC terminal and the system neutral terminal. The system actively controls the output differential voltages to account for variations in the electrical loading placed on the system. The system also actively controls the neutral voltage differential between the neutral terminal and Earth Ground. The output differential voltages are controlled to be maintained within an acceptable range for the types of electrical loads powered by the system (e.g. computers, servers, LED lighting) and to the extent the differentials vary, the system corrects the variances at frequencies which do not adversely affect system circuit protection or the electrical loading on the system.