Patent ID: 8331109
Filing Date: 2012-12-11
Classification: H02M

Abstract:
1. A circuit arrangement for reducing the load of semiconductor switches in transformer circuits with a primary side and a secondary side, comprising: a first semiconductor switch on the primary side; a second semiconductor switch on the primary side serially connected to the first semiconductor switch; a first terminal of a supply voltage, a drain terminal of the first semiconductor switch being connected to the first terminal; a second terminal of the supply voltage, a source terminal of the second semiconductor switch being connected to the second terminal; a primary winding of a transformer being connected between a source terminal of the first semiconductor switch and a drain terminal of the second semiconductor switch; a secondary winding of the transformer being connected to a secondary-side load; a first diode connected on an anode side to a potential of the supply voltage at the source terminal of the second semiconductor switch and on a cathode side by a first connection terminal between the first semiconductor switch and the primary winding of the transformer; a second diode connected on a cathode side to the potential of the supply voltage at the drain terminal of the first semiconductor switch and on an anode side to a second connection terminal between the second semiconductor switch and the primary winding of the transformer; a first auxiliary winding of the transformer having a sense of winding which is in the opposite direction compared to a sense of winding of the primary winding of the transformer, the first auxiliary winding being connected serially between the first diode and the first connection terminal on the primary winding of the transformer; and a second auxiliary winding of the transformer having a sense of winding which is in the opposite direction compared to the sense of winding of the primary winding of the transformer, the second auxiliary winding connected serially between the second diode and the second connection terminal on the primary winding of the transformer.