Patent attributes
There is described a power supply unit having at least one alternating current (AC) input and at least one direct current (DC) output for producing an output voltage. The power supply unit comprises at least one input transformer coupled to the at least one AC input and at least one rectification circuit defining an AC side and a DC side, and coupled to the at least one input transformer on the AC side. The at least one rectification circuit comprises a diode rectifier section on the AC side comprising at least one set of diode rectifiers, and a controlled rectifier section in series with the diode rectifier section and configured for producing a variable load voltage to modulate the output voltage between a base voltage and a maximum value of the output voltage using at least one set of three single-phase controlled rectifiers usable as one to three DC outputs to form a three-phase controlled rectifier.