| 摘要 |
The invention relates to a multichannel multimeter for direct measuring the effective values of tensions, currents and active power. Based on them, a microcontroller estimates full power, reactive power, phase angles between currents and tensions. The block diagram of the instrument consists of three identical blocks (A, B, C) connected to a microcontroller (8), which is plugged in a display (9) and a keyboard (10). Each of the blocks consists of a tension input circuit (1) and a current input circuit (4). The tension input circuit (1) is joined to an AD converter (2), which is connected to ascheme for calculating the effective value of the tension (3), the output of the latter being connected to the microcontroller (8). The current input circuit (4) is joined to an AD converter (5), which is connected to a scheme for calculating the effective value of the current (6), the output of the latter being connected to the microcontroller (8), while the outputs of the two AD converters (2 and 5) are connected to a multiplier (7), whose output is connected to microcontroller (8).
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