Abstract: An assembly includes a power supply and a meter. The power supply has a cable with a plurality of pins providing different voltages to a corresponding plurality of receiving pins. Each pin is connected to one of the receiving pins by a resistor of known value. The meter measures voltages of all of the resistors and all of the receiving pins simultaneously. Current passing through each of the resistors is calculated as a quotient of a voltage measured across each resistor and the known value of the resistor. Power delivered to each receiving pin is calculated as a product of the calculated current through the corresponding resistor and a voltage measured at the receiving pin with respect to ground. The total output power of the power supply is the sum of the powers calculated for each of the receiving pins.