US Patent 7701079 Automotive electrical system

Disclosed herein are a variety of different electrical system topologies intended to mitigate the impact of large intermittent loads on a 12 volt vehicle power distribution system. In some embodiments the intermittent load is disconnected from the remainder of the system and the voltage supplied to this load is allowed to fluctuate. In other embodiments, the voltage to critical loads is regulated independently of the voltage supplied to the remainder of the system. The different topologies described can be grouped into three categories, each corresponding to a different solution technique. One approach is to regulate the voltage to the critical loads. A second approach is to isolate the intermittent load that causes the drop in system voltage. The third approach is to use a different type of alternator that has a faster response than the conventional Lundell wound field machine.