Patent ID: 6353543
Filing Date: 2002-03-05
Classification: H02M

Abstract:
A switching circuit for a power conversion apparatus, wherein a driving transistor is connected to a switching main transistor to supply a driving power for ON-OFF driving thereto, an auxiliary power source composed of a current transformer being provided between said main transistor and said driving transistor, an auxiliary transistor having a lower switching loss than that of said main transistor being connected in parallel with said main transistor to form a main switch in combination with said main transistor, said switching circuit comprising;a current-driven type transistor serving as said main transistor, and voltage-driven type transistors serving as both of said driving transistor and said auxiliary transistor, wherein said auxiliary transistor is adapted to be driven at a higher speed than that of said main transistor when said main transistor is turned on, and adapted to be driven at a lower speed than that of said main transistor when said main transistor is turned off.