| 摘要 |
The electronic monitoring circuit for monitoring one of a group of series-connected capacitor units in an intermediate circuit in order to detect short-circuiting of one of the capacitor units includes a device for deriving a reference voltage ( 14 ) from an intermediate-circuit voltage (L(+), L(-)) applied across the series-connected capacitor units ( 1, 2 ), a device for generating a control signal consisting of a voltage difference between the reference voltage ( 14 ) and a junction voltage at a junction ( 13 ) between two capacitor units ( 1, 2 ) and a device for generating an error signal when said voltage difference falls below or exceeds an activation threshold voltage thus indicating that one of the capacitor units ( 1,2 ) has been short-circuited. The activation threshold voltage corresponds to a breakdown voltage of a zener diode provided in the monitoring circuit.
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