The present invention is a bilevel, cantilevered, welding cart with a rear cylinder rack and angled top platform. Generally, the apparatus includes a parallel-resonant trap coupled to the output of the active element, the trap including a network of reactive elements. The universal controls allow the number of controls included in the control panel of the system to be significantly reduced, since each universal control can perform functions of multiple hard controls. The first quantity of adjustable air outlet duct sections is based on an airflow rate value and the operating mode identifier. The device is handheld, or mountable on a headgear such as a helmet.