Patent ID: 9479072
Filing Date: 2016-10-25
CPC Classification: H02M

Claim Text:
1. Flyback converter circuit, having a transformer which has a primary winding and a secondary winding, each having a winding beginning and a winding end, a charging capacitor, a diode, a semiconductor switch and a controller, wherein a start transistor is provided which is coupled by its gate terminal to the winding beginning of the secondary winding of the transformer and is connected by its drain terminal to the winding end of the primary winding of the transformer, wherein an oscillator is formed at least by means of the transformer and the start transistor, the charging capacitor supplies the controller with energy and the diode is provided between the winding beginning of the secondary winding of the transformer and the charging capacitor, wherein the transformer, the charging capacitor, the diode, the semiconductor switch and the controller form a flyback converter, the controller is designed to control the semiconductor switch after the start of the flyback converter, and the anode of the diode is connected to the negative side of the charging capacitor, wherein the positive side of the charging capacitor lies on the negative or positive potential of the input voltage, the semiconductor switch is provided between the winding end of the primary winding of the transformer and the negative potential of the input voltage, the source terminal of the start transistor is coupled to the negative potential of the input voltage, and a voltage is created at the negative side of the charging capacitor which is below the negative potential of the input voltage and which is used to switch off the oscillator.