Power supply apparatus

A power supply apparatus comprising:

• a DC power supply;
• a series circuit including first and second current conducting devices connected in series across said DC power supply;
• first and second semiconductor switching devices connected in series across said DC power supply and adapted to be alternately rendered conductive;
• a load circuit connected between the junction of said first and second current conducting devices and the junction of said first and second semiconductor switching devices;
• a first snubber circuit connected in parallel with said first semiconductor switching device, said first snubber circuit comprising a first snubber capacitor and a first snubber unidirectionally conducting device connected in series with said first snubber capacitor in such a manner that said first snubber capacitor can be charged when said first semiconductor switching device is nonconductive;
• a second snubber circuit connected in parallel with said second semiconductor switching device, said second snubber circuit comprising a second snubber capacitor and a second snubber unidirectionally conducting device connected in series with said second snubber capacitor in such a manner that said second snubber capacitor can be charged when said second semiconductor switching device is nonconductive;
• a first regenerative circuit connected between said DC power supply and said first snubber capacitor;
• and
• a second regenerative circuit connected between said DC power supply and said second snubber capacitor;
• said first regenerative circuit being connected between the junction of said first snubber capacitor and said first snubber unidirectionally conducting device and said DC power supply, and including first voltage inducing means for converting a voltage across said load circuit and supplying a converted voltage to said first regenerative circuit when said first semiconductor switching device is conductive;
• said second regenerative circuit being connected between the junction of said second snubber capacitor and said second snubber unidirectionally conducting device and said DC power supply, and including second voltage inducing means for converting a voltage across said load circuit and supplying a converted voltage to said second regenerative circuit when said second semiconductor switching device is conductive.