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:
Jul. 17, 2018
Filed:
Sep. 20, 2012
Koninklijke Philips N.v., Eindhoven, NL;
Thomas Scheel, Stolberg, DE;
Christian Hattrup, Wurselen, DE;
KONINKLIJKE PHILIPS N.V., Eindhoven, NL;
Abstract
Non-linearities of a gradient amplifier () for powering a gradient coil () are caused by the finite dead time of the amplifier and/or by a forward voltage drop. The gradient amplifier () includes a controllable full bridge () and an output filter (). The full bridge () is controlled to provide a desired coil current (i), including receiving a desired duty cycle (a) of the gradient amplifier (), measuring an input current (i) and an output voltage (uc) of the output filter (), evaluating an modulator duty cycle (a), and providing the modulator duty cycle (a) for controlling the full bridge (). The gradient amplifier () powers a gradient coil () including at least two half bridges (), each having at least two power switches () connected in series. An output filter () connected to a tapped center points of the half bridges () between two the power switches (). A controller provides a desired duty cycle (a) of the gradient amplifier (), a compensation block () for providing an modulator duty cycle (a). A modulator () controls the power switches () according to the modulator duty cycle (a).