The EMHP series of power supplies is the highest power line of DC regulated high power units available in the range of 20-90 kW. Based on a regulated SCR phase control topology the EMHP series is ideally suited to applications where raw bulk power is required in a robust reliable package. All models are fully programmable sources of constant voltage and or constant current with automatic crossover and fully metered. In an SCR phase-controlled DC Power Supply, output is controlled by modulating the conduction angle of the controlling SCRs. The EMHP Series, input ac is applied to pairs of bi-directionally connected SCRs placed within the primary circuit of this transformer is rectified and L/C filtered to provide a low ripple DC output. Both output voltage and current are sensed and compared against internal references or externally applied control levels so the supply provides either constant voltage or constant current regulation with automatic crossover depending on control level. Additional circuitry provides bias levels, circuit protection and metering functions.