Method and apparatus for identification of an external power supply in a motor vehicle

Abstract

A device for identification of an external start is fitted in a vehicle which has an electrical on-board power supply system (14) fed with an on-board power supply system voltage of about 12.5 V via a vehicle battery (10). A negative pole (11) of the battery (10) is connected to a vehicle earth (15). A monitoring unit (13) is arranged between a positive pole (12) of the battery (10) and the on-board power supply system (14). A conventional voltage sensor (20) for detection of the on-board power supply system voltage, a similarly conventional current sensor (21) for detection of the current flowing out of the battery, and a conventional temperature sensor (22) for detection of the operating temperature of the battery (10) are provided in the monitoring unit (13). The main measurement variable is the on-board power supply system voltage; the battery current and the battery temperature represent auxiliary measurement variables in a monitoring algorithm. Furthermore, the monitoring unit (13) contains a microcontroller (23), which can identify a change in the on-board power supply system load via a CAN bus (25). As is indicated by the dashed line (26), the on-board power supply system load can also be detected directly via a controllable switch (24).

Dependencies are inferred from the claim text.