The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 06, 2013
Filed:
Mar. 31, 2011
Rixin Lai, Clifton Park, NY (US);
Luis Jose Garces, Niskayuna, NY (US);
Juan Antonio Sabate, Gansevoort, NY (US);
Juan Manuel Rivas Davila, Niskayuna, NY (US);
Song Chi, Clifton Park, NY (US);
Wesley Michael Skeffington, Clifton Park, NY (US);
Rixin Lai, Clifton Park, NY (US);
Luis Jose Garces, Niskayuna, NY (US);
Juan Antonio Sabate, Gansevoort, NY (US);
Juan Manuel Rivas Davila, Niskayuna, NY (US);
Song Chi, Clifton Park, NY (US);
Wesley Michael Skeffington, Clifton Park, NY (US);
General Electric Company, Niskayuna, NY (US);
Abstract
A gradient amplifier system is presented. An embodiment of a gradient amplifier system that includes a power stage having a plurality of bridge amplifiers, where each of the plurality of bridge amplifiers operates at a first switching frequency. The gradient amplifier system further includes a gradient coil coupled to an output terminal of the power stage and configured to produce a magnetic field proportional to a coil current signal supplied by the power stage. In addition, the gradient amplifier system includes 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, where the pulse width modulated gate signal is generated at a second switching frequency upon occurrence of a slew rate associated with the reference current signal is below a determined threshold rate and an amplitude level associated with the reference current signal is above a determined level. Further, the controller stage is configured to apply the generated 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 switching frequency to the second switching frequency.