A switching power system for converting an input voltage to an output voltage across a transformer is disclosed. The system includes a control circuit. The control circuit has a control input coupled for receiving the output voltage and an output coupled to a primary winding of the transformer. The system includes a bias circuit for supplying an operating voltage to the control circuit. The bias circuit includes a capacitor. The capacitor has a first terminal coupled to a first terminal of a first secondary winding of the transformer. A first diode is coupled between a second terminal of the first secondary winding and a second terminal of the first capacitor. A second diode is coupled between the second terminal of the capacitor and a bias input of the control circuit. A method of making the same is disclosed.