High-voltage power supply for x-ray tubes

An x-ray tube of a CT scanner is powered by a high-voltage power supply (26). The high-voltage power supply includes a plurality of sections (102) each having three straight-up transformers (48) which receive three 120 DEG phase shifted alternating current components as inputs. The straight-up transformers perform a direct voltage transformation with single or multiple transformers and with no capacitive multipliers. Each straight-up transformer has a primary winding (T1) and two secondary windings (T1-A, T1-B). The secondary windings are connected together in delta and wye configurations (84). The alternating current components have their voltage boosted and are rectified and summed to form a high-voltage output that is substantially ripple-free. A pulse-width modulated converter (34) generates a conditioned output current from an inputted direct current. Resonant inverters (36) receive the conditioned output current and convert the conditioned, direct current into alternating current received by each of the straight-up transformers (48) in the stack. The resonant inverters (36) operate at or near resonance. The power supply (26) has no added capacitance and stores a minimum of energy. It provides rise and fall times which enable the x-ray tube to perform sub-second exposures with very short rise and fall times.