Patent ID: 7616467
Filing Date: 2009-11-10
Classification: H02M

Abstract:
1. A circuit apparatus for transformerless conversion of an electric direct voltage of a two-pole direct voltage source ( 1 ) connected to ground having a first voltage pole (+) and a second voltage pole (−) into an alternating voltage for feeding into an alternating voltage network, a DC-AC converter ( 400 ) for feeding into said alternating voltage network being connected downstream of a DC-DC converter ( 300 ) and two capacitors ( 41 , 42 ) being present in an intermediate circuit between said DC-DC converter ( 300 ) and said DC-AC converter ( 400 ), said capacitors being connected in series and comprising a connection point (V) at ground potential so that a +/− voltage that is symmetrical with respect to ground potential ( 80 ) is available on the output side of the DC-DC converter stage ( 300 ), characterized in that there is provided: a first inverting buck-boost chopper ( and a second inverting buck-boost chopper ( the first buck-boost chopper ( said second buck-boost chopper (