Patent ID: 8531858

Claim:
A current-modulating power converter comprising: a link reactance which includes an inductor and a capacitor in parallel; multiple switches operable to connect said inductor of said link reactance, with reversible polarity, to any selected one of multiple external connections; and control circuitry, connected through a saturable sense inductor to sense zero-crossings of current through said inductor of said link reactance; wherein said sense inductor saturates more than ten times as quickly as said inductor of said link reactance; and wherein said control circuitry controls operation of said switches in at least partial dependence on an output of said saturable sense inductor; and wherein said sense inductor is arranged to saturate when current passing through the link reactance rises up to a limit; wherein said sense inductor rectifies voltage pulses occurring when current passing through the link reactance causes the sense inductor to pass out of and into saturation; and wherein said sense inductor uses the rectified voltage pulses to control the switches in at least partial dependence on the timing of the voltage pulses.