603,170. Electricity supply. BENDIX AVIATION CORPORATION. June 21. 1945, No. 15867. Convention date, March 2, 1944. [Class 38 (iv)] In a system for the parallel operation of a pair of generators G1, G2 feeding a bus line 10 through main switches 21, 21<SP>1</SP> respectively, regulating equipment associated with each generator and comprising, for example, a carbon pile 17 connected in series.with generator field 16, a calibrated drop' 20, a pair of regulating coils 22, 25 and an adjustable resistance 27, is connected through an adjustable potentiometer 30, whereby simultaneous adjustment of the output voltage of each generator may be effected in opposite senses in order to cause the regulators to maintain equal the loads on the two machines.