A multiple phase full wave motor drive transistor bridge inverter control circuit in which the base drive power supply for the transistors is transformer isolated from the on/off logic circuits, and the current control function for all of the inverter transistors is performed by a single current regulation circuit. A separate transformer is provided for each phase of the bridge inverter, and the transformer primaries are connected series to form the load of the current regulation circuit. The transformer secondaries supply base current to the upper and lower transistors of each respective phase, and the logic circuits schedule the conduction of the inverter transistors such that one transistor of each phase is always conductive, neglecting dead time. Each of the secondary circuits includes an impedance matching circuit to maintain balanced loading under conditions wherein the inverter transistors are reverse biased due to lagging power factor motor winding currents.