ALTERNATING CURRENT MEASURENING TOOL Russian patent published in 2008 - IPC G01R19/00 

FIELD: instrument engineering.

SUBSTANCE: proposed invention relates to electrical measuring and is designed for electronic instruments, which may be used in electronic power meters, transient process emergency recorders in power grids, in data collection systems for automated control system at power plants and substations. Alternating current measuring tool includes transformer with primary winding to be connected in series into the measured current circuit, and secondary winding, load resistance. Besides, front end of secondary current transformer winding is connected with the first output of load resistance. Besides, voltage source controlled by voltage is a part of instrument. Voltage source is provided with input, output and common terminals. The second resistance output is grounded and connected with common terminal of the said source. The first output of load resistance is also connected with input terminal of voltage source, and the end of secondary winding is connected with output terminal of voltage source. The said voltage source may be represented with non-inverting operational amplifier with voltage divider in negative reverse circuit.

EFFECT: invention is targeted to reduction of current transformer fault at given dimensions or reduction of transformer dimensions and weight at given error without additional winding and deterioration of dynamic characteristics of measuring circuit.

2 cl, 6 dwg, 2 tbl