shows a second embodiment of a regulating system according to the present invention in which in contrast to fig4 a pwm interface 10 is provided between control unit 4 and generator unit 8 in this embodiment diagnostic data and other information may be transmitted during an initialization phase from generator unit 8 to control unit 4 before the regulation begins the regulation then occurs with a time delay in the opposite direction 0046 fig6 shows the method steps of redundant voltage regulation in the form of a flow diagram in step 20 normal operation is carried out in which the regulation is performed by main regulator 1 in step 21 manipulated variable k transmitted by main regulator 1 is checked for plausibility by a logic system contained in generator unit 8 which may be integrated into auxiliary regulator 13 for example a threshold value for example being monitored if manipulated variable k or a function of manipulated variable k such as a df signal or the rate of change thereof for example is within predetermined threshold values sw case j normal operation nb is maintained when a predetermined threshold value sw case n is exceeded in step 22 auxiliary regulator 13 runs in non operational mode hb which ensures operation of generator 2 even if main regulator 1 fails an additional aspect of the present invention which results in more rapid availability of electrical power in the onboard.