ELECTRICITY METERING DEVICE Russian patent published in 2014 - IPC G01R11/00 

FIELD: electricity.

SUBSTANCE: device contains a phase current sensor, a multiplier multiplying a signal of the phase current sensor by the signal of effective voltage in the mains with further conversion of the product to a pulse frequency with division and counting of the pulse number in time and displaying the number at the digital display. A temperature-independent resistor is used as the phase current sensor connected to the operational amplifier with a controlled amplification factor which output is connected through the first rectifier with the first low-frequency filter to the first input of the multiplier at a microchip. A supply voltage resistor divider is connected to the second amplifier, and the supply voltage is converted into the pulsating voltage by the second rectifier with the second low-frequency filter. At that amplification control in the operational amplifier is implemented in steps by three decade resistor dividers as the output voltage of the operational amplifier exceeds the minimum or maximum fixed levels, for example, 1V and 10V, with simultaneous automatic changeover of the division ratio for the counted pulses in the frequency divider that includes two auxiliary decade counters. Either one counter or both counters are connected in series to the main circuit of the frequency divider for the respective ranges of current load measurement.

EFFECT: providing protection of the electricity metering devices from electric power theft.

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