Single phase and three phase AC to DC converters

An AC to DC converter supplied from an AC power line comprising:

• full wave rectifying means having input terminals coupled to said DC power line an output terminal providing rectified DC;
• a DC to DC converter coupled to the output of the full wave rectifier means, said DC to DC converter having a controllable switch means;
• filter means coupled between the output of said full wave rectifier and input of said DC to DC converter for blocking switching frequencies generated by said controllable switch means from reaching said AC power line;
• means for detecting a ringing of said filter means and developing a signal proportional to the ringing;
• means for coupling an external load to the output of said dc to dc converter;
• means for producing a reference sinusoidal waveform signal in phase with said input line voltage having means for adjusting the magnitude of said reference waveform signal;
• means for providing a waveform signal proportional to the current drawn from said AC power line by said AC to DC converter;
• means for comparing said reference waveform and current waveform signals and generating an error signal proportional to the difference;
• means for subtracting said signal proportional to the ringing from said error signal to dampen said filter ringing;
• and
• means responsive to said error signal for providing pulse width modulated signals to said controlling switch means to reduce said error signal and cause said current waveform to follow said reference waveform.