System and method to reduce power loss in a gradient amplifier
US9551767B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 10, 2012 |
| Grant date | Jan 24, 2017 |
| Priority date | — |
| Expiry date | Sep 16, 2035 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/543
- WIPO fieldMeasurement
- WIPO sectorInstruments
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.