| 摘要 |
1. A device for measuring the monophase reactive power of an electric network of the pulsation frequency omega, comprising a multiplier circuit (9) which receives at its inputs on the one hand a picture of the instant value of the network voltage (u) after having traversed a pi/2- delay circuit (10), and on the other hand a picture of the instant value of the current (i) circulating in said network, the output signal of the multiplier circuit (9) comprising terms of a pulsation frequency 2 omega and being sent to a filter (11) which delivers an output signal free of (2 omega)-terms, characterized in that said filter (11) is an active filter of the bridged double T type, the first T-branch of which consists of a first (21) and a second resistor (22) located in the horizontal part of the T and of a first capacitor (23) located in the vertical part of the T, the first branch being fed by a first operational amplifier (24), whereas the second branch consists of a second (25) and third capacitor (26) located in the horizontal part of the T, and of a third resistor (27) located in the vertical part of the T, said second branch being fed by a second operational amplifier (28), the rejection frequency of the filter being adjustable by means of potentiometers (29, 30) adjusting the gain of said two operational amplifiers (24, 28) which are fed by the output signal of the multiplier circuit (9).
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