Experimental results are presented for a three terminal, voltage regulated Josephson device. Superconducting (Sn) source and drain electrodes were weakly connected via thinned ohmic contacts and an accumulation layer induced at an Al.5Ga.5As/n-GaAs insulator/semiconductor interface. A maximum product of Josephson current times normal state resistance, IoRo, of 10 µV was registered at a gate voltage of 2.6 V and a temperature of 1.6 K.