A power supply assembly includes a housing having side walls, end walls, and a bottom wall defining a rectangular box with an interior space and an open top. A first dividing wall and a second dividing wall are positioned in the interior space of the housing which divides the interior space into first, second, and third compartments.A method of manufacturing a power supply with the above power supply assembly includes installing a printed circuit board in the second compartment and positioning the first wire set to terminate in the first compartment and the second wire set to terminate in the third compartment.