Abstract: In a magnetic resonance imaging (MRI) system, synchronized control of the operation of a gradient amplifier subsystem, a power supply subsystem, and a power distribution unit subsystem is accomplished by providing a coil command reference signal as an input to respective control blocks of the gradient amplifier subsystem, the power supply subsystem, and the power distribution unit subsystem. The coil command reference signal corresponds to a predetermined gradient coil current for at least one gradient coil of a scanner of the MRI system.

Abstract: A diagnostic device for diagnosing a faulty condition in a gradient amplifier system is presented. The diagnostic device includes a first current sensor configured to be coupled to an input terminal of a filter unit, where the first current sensor is configured to measure a first electric current at the input terminal of the filter unit, and where the first electric current includes a high frequency current component and a low frequency current component. Further, the diagnostic device includes a diagnostic unit coupled to the first current sensor and configured to determine an impedance across the filter unit and a load unit based on the low frequency current component of the measured first electric current and a pre-stored reference voltage, and diagnose the faulty condition of at least one component in at least one of the filter unit and the load unit based on a characteristic of the determined impedance.

Abstract: A switching amplifier includes a power device and a processing device. The power device is configured for powering a load and is comprised of a plurality of switches. The processing device configured to calculate a switch junction temperature for a bonding wire in each switch based at least in part on a power loss of each switch; generate a first accumulated fatigue damage of the bonding wire in each switch based on the switch junction temperature; and generate an estimated remaining lifetime of the switching amplifier based on the first accumulated fatigue damages of the bonding wires in each switch.

Abstract: Power systems and circuitry for generation of gradient magnetic fields in magnetic resonance imaging (MRI) systems are discussed herein. Embodiments may include the use of multiple gradient amplifiers that share a high-frequency power distribution unit, that may perform power distribution and power supply roles. The high-frequency power distribution unit may allow the use of a single power supply to drive multiple gradient amplifiers via a shared power bus. The gradient amplifiers may make use of modern semiconductor materials that provide high-frequency, high voltage performance, and may be implemented using single semiconductor bridges.

Abstract: A gate driver circuit is provided. The gate driver circuit includes an isolated gate driver power supply circuit. The isolated gate driver power supply circuit includes a coreless transformer and a resonance converter coupled to the coreless transformer. A method of manufacturing an isolated gate driver power supply circuit for a gate driver circuit is also provided.

Abstract: The present disclosure presents techniques to facilitate improving operation of an electrical system, which includes a bus structure that cascades multiple electrical devices. The bus structure includes a first outer conductive layer implemented as a positive layer; a second outer conductive layer implemented as a negative layer; a first intermediate conductive layer neighboring the first outer conductive layer; a second intermediate conductive layer neighboring the second outer conductive layer; and a third intermediate conductive layer neighboring the second intermediate conductive layer, in which the third intermediate conductive layer is implemented as an inter-device layer that facilitates electrically coupling at least two of the electrical devices in series.

Abstract: A pulsed power system is disclosed, which comprises at least two H-bridges cascaded for providing pulsed current to a load. Each H-bridge comprises at least two legs, and each leg comprises at least two transistor switches connected in series. Each transistor switch comprises a transistor and a diode electrically coupled with the transistor in parallel. The pulsed power system also comprises a controller configured to determine if a slew rate of the load current is lower than a threshold, and to reduce switching loss in response to the slew rate being lower than the threshold.

Abstract: This disclosure regards a magnetic resonance imaging system including a scanner, and gradient drivers. The scanner is to be implemented within a scan room that is shielded from electromagnetic interference. Gradient coils are designed to create a linear gradient in the magnetic field generated in the scanner by a primary magnet. These coils are energized by gradient drivers. The gradient drivers use transformers and other electrical devices in a switching stage configured to generate pulse-width-modulated power. The transformers may have non-magnetic cores to facilitate implementing the gradient drivers within the scan room. The gradient drivers also use a filtering stage which uses inductors and other electrical devices to smooth the pulse-width-modulated power. The inductors within the filters may have non-magnetic cores to facilitate implementing the gradient driver within the scan room. Additionally, an inductor with a hollow wire may be used to circulate fluid to facilitate cooling the gradient driver.

Abstract: The present disclosure presents techniques to facilitate improving operation of an electrical system, which includes a bus structure that cascades multiple electrical devices. The bus structure includes a first outer conductive layer implemented as a positive layer; a second outer conductive layer implemented as a negative layer; a first intermediate conductive layer neighboring the first outer conductive layer; a second intermediate conductive layer neighboring the second outer conductive layer; and a third intermediate conductive layer neighboring the second intermediate conductive layer, in which the third intermediate conductive layer is implemented as an inter-device layer that facilitates electrically coupling at least two of the electrical devices in series.

Abstract: A switching amplifier includes a plurality of cascade elements, each bridge circuit includes an inductive load coupled between a first leg terminal of one of the at least two leg circuits and a second leg terminal of another one of the at least two leg circuits. A first leg voltage of the first leg terminal have a phase shift relative to a second leg voltage of the second leg terminal, the phase shift is used for causing the inductive load to store electric energy and generating a minimum circulating current?I min or I min sufficient to effect conducting of a corresponding diode; each of the switches is configured to be turned on if the corresponding diode conducts current to effect zero voltage switching of the corresponding switch. The minimum circulating current?I min or I min is equal to a constant value.

Abstract: The present disclosure relates possible implementations for utilizing energy storage elements in conjunction with a MRI system. Similarly, various associated control mechanisms are discussed. In certain embodiments, one or both of peak power shaving or energy backup may be facilitated by use of the energy storage elements. Certain such implementations may facilitate the use of higher-power MRI systems with an existing electrical infrastructure.

Abstract: An ultrasound pulse generator circuit includes a first gate driver electrically coupled to a first gallium nitride (GaN) transistor, a second gate driver electrically coupled to a second GaN transistor, a first snubber circuit, a second snubber circuit, and a transformer. The first snubber circuit and the second snubber circuit each include a respective capacitor and resistor and each snubber circuit is configured to clamp a voltage overshoot when present. Further, the transformer generates an output signal when operated and the third transformer is electrically connected downstream of the first GaN transistor, the second GaN transistor, the first snubber circuit, and the second snubber circuit. In addition, the transformer includes multiple windings.

Abstract: A system including at least one first converter and a filtering unit coupled to the at least one first converter is presented. The filtering unit includes at least one second converter and a plurality of inductors coupled to the at least one second converter. The system further includes a controlling unit operatively coupled to the at least one first converter and the at least one second converter. The controlling unit switches the at least one first converter to generate a first output voltage and the at least one second converter to generate a second output voltage, where the first output voltage and the second output voltage have a substantially same switching pattern.

Abstract: A switching amplifier includes a power device and a processing device. The power device is configured for powering a load and is comprised of a plurality of switches. The processing device configured to calculate a switch junction temperature for a bonding wire in each switch based at least in part on a power loss of each switch; generate a first accumulated fatigue damage of the bonding wire in each switch based on the switch junction temperature; and generate an estimated remaining lifetime of the switching amplifier based on the first accumulated fatigue damages of the bonding wires in each switch.

Abstract: A switching amplifier includes a plurality of cascade elements, each bridge circuit includes an inductive load coupled between a first leg terminal of one of the at least two leg circuits and a second leg terminal of another one of the at least two leg circuits. A first leg voltage of the first leg terminal have a phase shift relative to a second leg voltage of the second leg terminal, the phase shift is used for causing the inductive load to store electric energy and generating a minimum circulating current—I min or I min sufficient to effect conducting of a corresponding diode; each of the switches is configured to be turned on if the corresponding diode conducts current to effect zero voltage switching of the corresponding switch. The minimum circulating current—I min or I min is equal to a constant value.

Abstract: Systems and methods for controlling an electrical power supply are provided. One system includes an input configured for receiving voltage measurement signals for the power supply and a controller for one or more electrical phases of the power supply. The controller includes an integrator configured to integrate the received voltage measurement signals and to generate integrated control signals or integrated error signals. The controller is configured to generate an output signal using the integrated control signals or the integrated error signals. The system also includes an output configured to output the output signal to control switching of the power supply.

Abstract: The present disclosure relates possible implementations for utilizing energy storage elements in conjunction with a MRI system. Similarly, various associated control mechanisms are discussed. In certain embodiments, one or both of peak power shaving or energy backup may be facilitated by use of the energy storage elements. Certain such implementations may facilitate the use of higher-power MRI systems with an existing electrical infrastructure.

Abstract: A gradient amplifier system, includes: a power stage comprising a plurality of bridge amplifiers, each operates at a first switching frequency; a gradient coil coupled to the power stage and configured to produce a magnetic field proportional to a coil current signal supplied by the power stage; a controller stage coupled to an input terminal of the power stage and configured to: generate a pulse width modulated gate signal based on the coil current signal and a reference current signal, wherein the pulse width modulated gate signal is generated at a second switching frequency when a slew rate associated with the reference current signal is below a threshold rate for at least a first time period; and apply the pulse width modulated gate signal to the power stage for changing an operating frequency of each of the plurality of bridge amplifiers from the first to the second switching frequency.

Abstract: A resonant power supply is disclosed. The resonant power supply includes a series resonant configured to convert an input DC voltage to an output DC voltage. The resonant power supply further comprises a converter controller coupled to the series resonant converter and configured to receive a DC voltage feedback signal measured at the output of the series resonant converter, or a resonant current feedback signal representing a resonant current flowing through the series resonant converter. The converter controller is further configured to generate control signals to be applied to the series resonant converter to limit the output DC voltage of the series resonant converter according to the DC voltage feedback signal and a predetermined voltage threshold signal, or to limit the resonant current of the series resonant converter according to the resonant current feedback signal and a predetermined current threshold signal.

Abstract: In one embodiment, a system includes a gradient coil driver configured to supply electrical signals to a gradient coil of a magnetic resonance imaging system. The gradient coil driver includes an electronic circuit. The electronic circuit includes a first H-bridge circuit electrically coupled to a power source. The first H-bridge includes a plurality of metal-oxide-semiconductor field-effect transistor (MOSFET) switches; and a plurality of diodes electrically coupled in parallel with each MOSFET switch. Each diode of the plurality of diodes is configured to conduct current to cause zero voltage potential across a source and a drain of one of the plurality of MOSFET switches. The first H-bridge also includes a load configured to regulate currents flowing through each of the plurality of diodes and each MOSFET switch of the plurality of MOSFET switches.