A constant current regulator for airfield ground lighting is described herein. For example, one or more embodiments include a power converter configured to receive a signal from an alternating current (AC) mains, where the power converter includes a number of bi-directional switches, a transformer configured to isolate the AC signal from an airfield ground lighting circuit, and a rectifier configured to convert the signal from the AC mains from AC to direct current (DC), an inverter configured to convert the DC signal from the power converter and convert the DC to AC, an output filter configured to receive the AC signal from the inverter and send the AC signal to the airfield ground lighting circuit, and a controller configured to switch the number of bi-directional switches of the power converter to allow an input voltage and current of the signal from the AC mains to be in phase.