Patent ID: 8492924

Claim:
A power supply system comprising: a transformer having a primary winding, a first secondary winding with a first terminal of the first secondary winding coupled to a first secondary output of the power supply system, and having a second secondary winding coupled to a first low voltage output of the power supply system; a switching power supply controller coupled to control the primary winding to form a first output voltage on the first secondary winding and to form a second output voltage on the second secondary winding; a first blocking device configured to couple the first output voltage to the first secondary output of the power supply system as a secondary voltage; a second blocking device configured to couple the second output voltage to the first low voltage output of the power supply system as an auxiliary voltage; and a first regulator configured to operate as a linear voltage regulator that is coupled between the first secondary winding and the first low voltage output to receive the first output voltage from the first secondary winding and supply a first regulated voltage to the first low voltage output that has a lower value than the secondary voltage, the first regulator including a third blocking device coupled to receive the first output voltage from the first secondary winding and a series pass transistor configured to operate as the series pass transistor of the linear voltage regulator and coupled in series with the third blocking device between the first secondary winding and the second secondary winding to receive a voltage from the third blocking device and regulate a value of the first regulated voltage.