a power supply system is disclosed wherein redundant d . c . power supplies are provided for a single load , each of the supplies being capable of providing full load current so that one of the supplies may be removed without interrupting power to the load . each of the power supplies has a differential amplifier type of voltage regulator that includes a resistor in series with the output lead so that it is capable of varying the output voltage to compensate for lead and or - ing rectifier drops .