Power supply apparatus with initial arcing sustaining circuit

A power supply apparatus comprising:

• inverter means for converting a first DC voltage into a high frequency voltage;
• transformer means for voltage-transforming said high frequency voltage;
• first converting means for converting the voltage-transformed high frequency voltage into a second DC voltage;
• two output terminals between which the second DC voltage from said first converting means is applied;
• a high frequency voltage superposing path coupled between said output terminals;
• high frequency voltage generating means;
• a coupling transformer having a primary winding and a first secondary winding, said primary winding receiving a high frequency voltage from said high frequency voltage generating means, said first second winding being coupled in said high frequency voltage superposing path;
• voltage boosting means for developing a boosted high frequency voltage in accordance with the high frequency voltage generated by said high frequency voltage generating means;
• and
• second converting means associated with said voltage boosting means for converting the boosted high frequency voltage into a third DC voltage and applying the third DC voltage between said output terminals;
• wherein said high frequency voltage generating means stops providing the high frequency voltage when arc current flows between said output terminals.

A power supply apparatus comprising:

• an inverter for converting a first DC voltage into a high frequency voltage;
• a transformer for voltage-transforming said high frequency voltage;
• a first converter for converting the voltage-transformed high frequency voltage into a second DC voltage;
• two output terminals between which the second DC voltage from said first converter is applied;
• a high frequency voltage superposing path coupled between said output terminals;
• a high frequency voltage generator;
• a coupling transformer having a primary winding and a first secondary winding, said primary winding receiving a high frequency voltage from said high frequency voltage generator, said first secondary winding being coupled in said high frequency voltage superposing path;
• a voltage booster for developing a boosted high frequency voltage in accordance with the high frequency voltage generated by said high frequency voltage generator;
• and
• a second converter associated with said voltage booster for converting the boosted high frequency voltage into a third DC voltage that is higher than the second DC voltage and applying the third voltage between said output terminals.

A power supply apparatus comprising:

• an inverter for converting a first DC voltage into a high frequency voltage;
• a transformer for voltage-transforming said high frequency voltage;
• a first converter for converting the voltage-transformed high frequency voltage into a second DC voltage;
• two output terminals between which the second DC voltage from said first converter is applied;
• a high frequency voltage superposing path coupled between said output terminals;
• a high frequency voltage generator;
• a coupling transformer having a primary winding and a first secondary winding, said primary winding receiving a high frequency voltage from said high frequency voltage generator, said first secondary winding being coupled in said high frequency voltage superposing path;
• a voltage booster for developing a boosted high frequency voltage in accordance with the high frequency voltage generated by said high frequency voltage generator;
• and
• a second converter associated with said voltage booster for converting the boosted high frequency voltage into a third DC voltage and applying the third DC voltage between said output terminals;
• wherein said high frequency voltage generator stops providing the high frequency voltage when arc current flows between said output terminals.