| 摘要 |
FIELD: instrumentation.SUBSTANCE: invention relates to measurement of electric quantities, namely to measuring the active current component in three-phase networks. In a device for the measurement of active current in a three-phase voltage source the following units are used as measuring transducers: the first and the second differentiating induction current transducers whose coils are inductively connected to the same current lead of load current which is connected to the second terminal of the three-phase voltage source, and second output terminals of the first and second bridge rectifiers are combined in one unit to which second extreme terminals of the first and second variable resistors are connected. Starting points of the coils of the first and the second differentiating induction current transducers are connected respectively to the second input terminals of the first and second bridge rectifiers, and the outputs of the movable contacts of the first and second variable resistors are the output terminals of the device.EFFECT: technical result of the proposed invention consists in reduced material inputs due to the replacement of two current transformers having great weight and price, by two differentiating induction current transducers, and simplified design and as a consequence lower labour inputs due to the fact that the device is fitted by two but not four output terminals to which the difference of voltages of the first and second bridge rectifiers proportional to the active current of the voltage source is supplied.2 dwg |
