Typically, the alternator in a vehicle is not able to provide the current required by the automotive loads when the vehicle is at idle. One of the reasons for this situation is that the field voltage cannot exceed battery voltage and another reason is that the relatively large synchronous inductance limits the current drawn from the stator. In this paper, the former will be addressed using a novel buck / boost circuit configuration which uses only one transistor. The stator synchronous inductance will be compensated by changing the phase of the load, using a 6-FET synchronous rectifier. This synchronous rectifier is controlled without the use of a position sensor and without knowledge of alternator parameters such as resistance, inductance.