This voltage source is designed to bias superconducting tunnel junctio
ns when studying their current-voltage characteristics at voltages ran
ging from zero to several millivolts. The source has been used in expe
riments with junctions whose resistances ranged from 10(-2) to 10(3) O
mega, breakdown voltages from 0.1 to 10 V; and maximum dissipated powe
rs; from 0.1 to 100 mW. The device allows the current and voltage to b
e measured across circuit components with resistances under 100 Omega
to within 0.1%.