SYNCHRONOUS FLYBACK CONVERTER CIRCUIT

The present invention relates to a flyback converter circuit (3) which has a first controllable switch (8) with a capacitor (14); a second controllable switch (11); a transformer (7) with a primary winding (6) which is coupled to the first switch (8) and a secondary winding (10) which is coupled to the second switch (11); a controller (13) which is configured to switch off the second switch (11) when the current through the second switch (11) has reached a negative value after it has decreased to zero, wherein the capacitor (14) is charged after the first switch (8) is switched off and discharged after the second switch (11) is switched off; and a device (1) for establishing the discharge rate of the capacitor (14) in order to determine a current flowing through the second switch (11) at the time at which it is switched off. 本发明涉及一种反激式转换器电路(3)，所述反激式转换器电路具有：可控制的第一开关(8)，具有电容(14)；可控制的第二开关(11)；变压器(7)，具有初级绕组(6)，所述初级绕组与所述第一开关(8)耦合，和次级绕组(10)，所述次级绕组与所述第二开关(11)耦合；控制设备(13)，所述控制设备设计用于在通过所述第二开关(11)的电流在降至零之后达到负值时关断所述第二开关(