Inverter device, gradient amplifier, and magnetic resonance imaging device
AssigneeCanon Medical Systems Corporation
InventorKoichi Yamakawa
Life of this patent
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Abstract
An inverter device according to an embodiment includes a plurality of switching elements and processing circuitry. The switching elements are connected to each other in parallel, and each of them includes a transistor and a free wheeling diode connected to the transistor in antiparallel. The processing circuitry is configured to monitor a current flowing through the free wheeling diode included in each switching element or a temperature of the free wheeling diode and to control, in accordance with the current or the temperature, a load on each free wheeling diode to prevent unbalance of loads between free wheeling diodes in the switching elements.
Claims10
An inverter device comprising:
- a plurality of switching elements that are connected to each other in parallel and each include a transistor and a free wheeling diode connected to the transistor in antiparallel;
- and
- processing circuitry configured to monitor a current flowing through the free wheeling diode included in each switching element or a temperature of the free wheeling diode and to control, in accordance with the current or the temperature, a load on each free wheeling diode to prevent unbalance of loads between free wheeling diodes in the switching elements.
A gradient amplifier comprising an inverter device that outputs a voltage corresponding to a waveform of a gradient magnetic field to a gradient coil used in a magnetic resonance imaging device, wherein
- the inverter device includes
- a plurality of switching elements that are connected to each other in parallel and each include a transistor and a free wheeling diode connected to the transistor in antiparallel;
- and
- processing circuitry configured to monitor a current flowing through the free wheeling diode included in each switching element or a temperature of the free wheeling diode and to control, in accordance with the current or the temperature, a load on each free wheeling diode to prevent unbalance of loads between free wheeling diodes in the switching elements.
A magnetic resonance imaging device comprising:
- a gradient coil that applies a gradient magnetic field to an imaging space where a subject is located;
- and
- a gradient amplifier including an inverter device that outputs a voltage corresponding to a waveform of the gradient magnetic field to the gradient coil, wherein
- the inverter device includes
- a plurality of switching elements hat are connected to each other in parallel and each include a transistor and a free wheeling diode connected to the transistor in antiparallel;
- and
- processing circuitry configured to monitor a current flowing through the free wheeling diode included in each switching element or a temperature of the free wheeling diode and to control, in accordance with the current or the temperature, a load on each free wheeling diode to prevent unbalance of loads between free wheeling diodes in the switching elements.
Dependencies are inferred from the claim text.