| 摘要 |
The invention relates to a capacitive voltage reducer. Its object is a reducer which, for each phase of an electrical power line whose voltage is to be measured, comprises a first capacitor (C1) connected on the one hand to one phase of an electrical power line and on the other hand, through a connecting cable (2), to a preamplifier consisting of an operational amplifier (A) fitted with a second capacitor (C2), in parallel with a first resistor (R2), between its negative input and its output; the reducer also comprises a line discharge resistor connected between the phase line and earth (RL) or between the phase line and the low voltage plate of the first capacitor (R'L), a third capacitor C3 connected between the low voltage plate of the first capacitor and earth, a low-pass filter (3) on the input side of the preamplifier and a slaved power amplification stage (AS) including a high-pass filter and supplying mainly the counting circuits (9) and the protective circuits (10). Application in operating electrical power supply networks. <IMAGE>
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