PRECISION GRADIENT AMPLIFIER WITH MULTIPLE OUTPUT VOLTAGE LEVELS

摘要

A controlled power supply (201, 222) drives a magnetic field gradient coil (161) of a magnetic resonance imaging apparatus (10). A gradient amplifier (201) includes a plurality of switching power regulators (50, 52, 54, 56) which are electrically connected in series. A bipolar circuit (70) receives power from the series connected switching power regulators (50, 52, 54, 56) and delivers the power at a selected polarity to the gradient coil (161). A control circuit (221) delivers phase staggered pulse width modulated control signals (A, B, C, D) to the switching power regulators (50, 52, 54, 56).