This regulated power source is designed to provide extremely accurate and stable D.C. output with less than 100 microvolts of ripple and noise content. Two dual concentric decade switches provide digital presentation of a selected output voltage to four places. A calibrated potentiometer permits interpolation to a fifth digit (Model 2020B) and sixth digit {Models 5020 & C500). The mode! 2020B includes a toggle switch for 10-20 volt operation with no change in resolution. The calibration for all models is 0.1% of the dial settings. The output voltage of the supply may be remotely programmed with an external resistance without loss of accuracy. Rear terminals provide for remote sensing of the output voltage at the load. Calibrated output is available through either pane! mounted binding posts of a rear mounted terminal strip. Metering is provided by means of a dual scale edgewise meter. A function switch selects voltage or current monitoring. Current limiting is continuously adjustable by means of a front pane! control. The “pull-to- set” switch permits adjustments of the current limit point without shorting the output terminals. A flashing panel lamp indicates an overload or short condition. The power supply is floating with respect to the chassis permitting positive or negative polarity. The output may be continuously shorted without damage to the power source. Each power supply is “burned in” for 100 hours prior to test and shipment with calibration data. The power source is housed in a blue enamel cabinet. The front panel is brushed aluminum with black nomenclature. A tilting bail assembly is provided for ease of viewing. Panel adaptors are available for mounting one or two units in a standard 19 inch rack.