Method and apparatus for energy conversion utilizing circuit phase and time variables
AssigneeGE Medical Systems SA
InventorJacques Laeuffer
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Abstract
A conversion apparatus having transistors, comprising means for inverting a DC voltage in order to obtain an AC voltage, means for filtering the AC voltage, including at least one parallel inductor Lp, the device being capable of operating above a resonant frequency Fp. The conversion apparatus comprises means for predicting a zero crossing of the instantaneous current I1p in the parallel inductor Lp, and means for causing a transistor of the device to switch if a zero crossing of the current I1p is predicted.
Claims16
Apparatus for converting DC voltage to AC voltage comprising:
- an inverter for receiving DC voltage and providing unfiltered AC voltage at an operating frequency, said inverter having transistors operable between conductive and nonconductive states;
- filtering means for filtering said AC voltage, said filtering means having at least one resonant circuit formed of a capacitor and a first inductor connected in parallel and possessing a first resonant frequency determined by the values of said capacitor and said first inductor with said first resonant frequency being different from said operating frequency;
- means for measuring current flowing in said filtering means through said first inductor;
- and
- comparator means responsive to the amplitude of said current to provide an output signal for switching at least one of said transistors from its nonconductive state to its conductive state at a pre-selected time period.
A method of converting DC voltage to AC voltage comprising the steps of:
- receiving said DC voltage and providing unfiltered AC voltage at an operating frequency utilizing transistors operable between conductive and nonconductive states;
- filtering said AC voltage utilizing a resonant circuit formed of a capacitor and an inductor connected in parallel and possessing a resonant frequency determined by the values of said capacitor and said inductor said resonant frequency being different from said operating frequency;
- measuring the amplitude of current flowing through said inductor;
- and
- providing an output signal in response to the measured amplitude of said current for switching at least one of said transistors from its nonconductive state to its conductive state at a pre-selected time period.
Dependencies are inferred from the claim text.