A steering system functions in accordance with the steer by wire concept and has a normal operating system without positive coupling between the steering handle and the steered vehicle wheels, as well as an emergency operating system, which functions with positive coupling between the steered vehicle wheels and the steering handle. The resultant open-celled polyurethane spray foam has a density of about \xbd pound per cubic foot. The integrated converter utilizes the same single inductor during each of the three operating modes to reduce cost and weight of the system.