Abstract: A power supply unit (130) powers at least one gradient coil (128) of a magnetic resonance (MR) examination system (110) with a main magnet (114) having, in at least one state of operation, a substantially static magnetic field strength, and with an MR measurement signal bandwidth. The power supply unit (130) includes a switched-mode power converter (134) for powering the at least one gradient coil (128), and including at least one switching member provided to switch between a conducting state configuration and an essentially non-conducting state configuration at a first fundamental switching frequency (fSW). A pulse control unit (132) is designed to provide switching pulses at the first fundamental switching frequency (fSW) for controlling the switching of the at least one switching member. Upon triggering by a trigger signal (142), the pulse control unit (132) is provided to change the first fundamental switching frequency (fSW) to at least a second fundamental switching frequency (fSW).

Abstract: A power supply unit (130) for powering at least one gradient coil (128) of a magnetic resonance (MR) examination system (110) with a main magnet (114) having, in at least one state of operation, a substantially static magnetic field strength, and with an MR measurement signal bandwidth, the power supply unit (130) comprising: a switched-mode power converter (134) for powering the at least one gradient coil (128), comprising at least one switching member provided to switch between a conducting state configuration and an essentially non-conducting state configuration at a first fundamental switching frequency (fSW); a pulse control unit (132) designed to provide switching pulses at the first fundamental switching frequency (fSW) for controlling the switching of the at least one switching member; wherein, upon triggering by a trigger signal (142), the pulse control unit (132) is provided to change the first fundamental switching frequency (fSW) to at least a second fundamental switching frequency (fSW).