Patent ID: 8330448

Claim:
A system comprising: a power supply unit supplied with an alternating current (AC) power source, the power supply unit capable of supplying a plurality of power rails to an electronic load; a power meter connected between the AC power source and the power supply unit and capable of measuring an input power supplied to the power supply unit; a plurality of switches; a multimeter capable of connecting to each of the power rails via at least one of the plurality of switches for measuring an output power of each of the power rails; a microcontroller unit (MCU) for automatically switching the plurality of switches for enabling the multimeter to measure the output power of each of the power rails; a relay control center connected to the MCU and capable of controlling on/off states of the plurality of switches; a computer respectively connected to the power meter, the multimeter, and the MCU, the computer capable of reading data measured from the power meter and the multimeter, informing the MCU to switch on/off the plurality of switches according to a predetermined sequence, and calculating a conversion efficiency of the power supply unit; and a signal conversion circuit connected between the MCU and the computer, the signal conversion circuit capable of converting signals sent from the computer to Transistor-Transistor Logic (TTL) level signals which are receivable by the MCU; the plurality of switches comprises a double pole-double throw switch capable of switching from a first closed position to a second closed position.