A popular, advanced, continuously-variable power supply unit with LED digital display, the Edu-Lab College Power Supply Unit is ideal for demonstration purposes and for use by students in advanced level courses. It provides a fine and smooth, continuously-variable AC or DC voltage at a combined maximum current of 8.5A. The DC is smoothed by an internal 2200F capacitor. AC or DC voltage reading is selected by a toggle switch and indicated by a bright green, easy-to-read 12.5mm LED display. Microprocessor tripping circuitry will differentiate between a real short-circuit or a temporary current surge.