Patent ID: 7582978
Filing Date: 2009-09-01
Classification: F02B,H02P

Abstract:
1. An auxiliary power unit for a motor vehicle that is powered by a primary engine and that has a battery connected to an electrical system to which the primary engine is connected, said auxiliary power unit comprising: an auxiliary engine having an output shaft; a generator having a rotor with a field winding wound thereon and coupled to the output shaft, a first output winding in which a first voltage of alternating current is generated for application to electrical outlets in the motor vehicle for powering AC loads, a second output winding in which a second voltage is generated for powering the electrical system, and an auxiliary winding in which a third voltage is generated; and a controller that senses one of the first voltage, the second voltage and the third voltage and in response thereto controls excitation of the field winding with the third voltage in a manner wherein the third voltage is used exclusively for exciting the field winding.