Monitoring of power supply network

The electrical circuit has a generator (15) and an accumulator battery (8) in parallel. They supply the vehicle electrical network (14) with a DC voltage (U BN). A parking brake control circuit (6) is connected to a hydraulic pump (7) and a hydraulic control circuit (5). The hydraulic control circuit feeds hydraulic fluid through a pressure line (9) to a locking device (12) on the vehicle wheel disk brake (11,13). Further users (16,17) are connected in parallel with the brake control system.