The present disclosure generally describes a system that includes a heater, a power converter including a power switch, and a controller. The power converter is in communication with the heater and is operable to apply an adjustable voltage to the heater. The controller is in communication with the power switch to control the voltage output of the power converter based on at least one of a load current and a detected voltage at the heater. The controller operates the power switch to adjust the voltage output of the power converter.