Patent ID: 8339822

Claim:
A method for operating a transformer ( 130 ) comprising a transformer core ( 131 ) having a primary coil ( 132 ) and a secondary coil ( 133 ) which is connected into a secondary circuit ( 120 ), comprising the steps of: regulating a magnetic flux density (B) in the transformer core ( 131 ) between an upper flux density threshold value (Bm) and a lower flux density threshold value (−Bm), regulating a load current (i br ) in the secondary circuit ( 120 ) between an upper load current threshold value (i br-zg ) and a lower load current threshold value (i br-sp ), wherein the steps of regulating the magnetic flux density (B) and the load current (i br ) include applying, in alternation, a first voltage (U DC ) and a second voltage (−U DC ) and a third voltage (0V) to the primary coil ( 132 ) of the transformer ( 130 ), wherein the first voltage (U DC ) and the second voltage (−U DC ) are direct voltages that are of the same magnitude and opposite polarity and the third voltage (0V) is zero, and wherein the load current (i br ) increases when any one of the first voltage (U DC ) and the second voltage (−U DC ) is applied and, decreases when the third voltage (0V) is applied, to the primary coil ( 132 ) of the transformer.