CURRENT INVERTER Russian patent published in 2005 - IPC

FIELD: converter engineering; power supplies for induction heaters.

SUBSTANCE: proposed current inverter built in the form of single-phase bridge around transistors with series-connected diodes and transistor shunting diodes is provided with newly introduced series circuits of which one incorporates voltage limiter and two resistors, other circuit has voltage limiter, and third one, two resistors, two diodes, and two capacitors. Each series circuit shorts out single-phase bridge built around transistors and connected to input leads through filter chokes. Third series circuit is connected to collector and emitter groups of single-phase bridge transistor through fourth and fifth series circuits, each incorporating diode, resistor, and choke. In case of open circuit in induction heater thyristor is turned on to short out single-phase bridge through capacitor that limits input voltage of inverter in response to thyristor failure. Input voltage of inverter is limited by limiting voltage across first series circuit.

EFFECT: enhanced operating reliability and noise immunity of current inverter; reduced switching loss and voltage surges.

1 cl, 1 dwg