Patent ID: 7050313

Claim:
An AC-DC converter unit that is coupled to a generator, comprising: a DC reference voltage generation unit configured to create a DC reference voltage waveform based in part on a DC feedback signal; an SCR firing unit configured to receive a variable frequency voltage output from the generator and to provide a plurality of firing signals; a plurality of SCRs including a positive bank of SCRs and a negative bank of SCRs; a modulator unit configured to receive the firing signals from the SCR firing unit and the DC reference voltage waveform, and to respectively output a plurality of modulated signals; an SCR driver unit configured to output SCR gate signals to the plurality of SCRs based on the plurality of modulated signals output by the modulator unit, wherein an output of the plurality of SCRs corresponds to a rectified voltage waveform; a filter unit connected directly between the positive and negative banks of SCRs such that respective outputs of the positive and negative banks of SCRs are not directly connected to each other, the filter unit configured to filter the rectified voltage waveform to provide a filtered rectified voltage waveform as a DC output voltage of the AC-DC converter; and a voltage feedback path for feeding back the DC output voltage as the DC feedback signal, wherein the modulator unit directly receives the DC reference voltage waveform, as a DC voltage value, output by the DC reference voltage generation unit, and wherein the modulator unit modulates the DC reference voltage waveform with the firing signals output by the SCR firing unit.