Abstract: A solid electrolyte gas analyzer includes an analyzer circuit housed in an electronics housing and a probe housing for immersion in the gas of interest. The electronics housing mounts directly to the probe housing, preferably through a standoff. The analyzer circuit is powered by an AC line input and includes a switching power supply to convert the AC line input to DC power useable by the analyzer circuit. The analyzer circuit also includes a heater circuit controlling a heater in the probe housing. The power supply and the heater circuit automatically adjust to different AC line input voltage levels. The switching power supply efficiently supplies DC power to other portions of the analyzer circuit with little heat generation.