Patent ID: 8339810

Claim:
A power supply unit comprising: an input circuit configured to receive an AC input signal; a rectifier configured to convert the AC input signal to a DC link signal; a variable pulse width modulation (PWM) controller configured to supply a drive signal based upon a switching frequency; a drive circuit comprising a power transistor configured to produce a switched DC signal from the DC link signal under the control of the drive signal; a transformer comprising a primary winding and a secondary winding, wherein the transformer is configured to receive the switched DC signal on the primary winding and to produce a first transformer output signal and a second transformer output signal on the secondary winding; a diode half bridge configured to receive the first transformer output signal and to produce a first DC output signal; and a diode configured to receive the second transformer output signal and to produce a second DC output signal; wherein the first DC output signal is utilized for powering control logic for a ground power unit (GPU), and wherein the second DC output signal is utilized for driving a power converter of the GPU.