| 摘要 |
The subject-matter of the invention is a circuit arrangement for monitoring and for the sequence-controlled switching on and off of power supply units in the event of voltage reductions or failures. The supply voltage for the power supply units (49, 50, 51) is monitored at a lower limit, and a warning signal is produced if the voltage falls below this limit. The warning signal causes an alarm signal for the duration of a delay time which depends on the supply voltage dropping below a specific threshold value, said supply voltage being buffered by an energy store. After the end of the delay time, cut-off signals are produced for the respective power supply unit and for further power supply units which are jointly arranged with said unit in a monitoring loop. Once the supply voltage is re-applied to the power supply units (49, 50, 51), the output DC voltages are tested after a time which can be predetermined. If at least one of the output DC voltages deviates from the desired value, the respective power supply unit is cut off. <IMAGE>
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