FIG. 1 is a perspective view of the direct current power supply; FIG. 2 is a front view of the direct current power supply, the back view being a mirror image the front view; FIG. 3 is a bottom view of the direct current power supply; FIG. 4 is a top view of the direct current power supply; and, FIG. 5 is a right side view of the direct current power supply, the left side view being a mirror image the right side view.