THERMOELECTRIC SENSOR INTENDED TO MEASURE THE TRUE EFFECTIVE CURRENT

摘要

The disclosed sensor measures the true effective value of a current by comparing the thermal effects produced by the current to be measured with a known comparison current, on two heating resistors, a measuring resistor (5) and a comparison resistor (6), by means of a circuit comprised of series thermocouples (1), so that each pair of junctions in electric opposition is heated by the thermal flow coming from each of the heaters, the measuring heater (5) and the comparison heater (6), generating at their terminals an electromotive force - error signal - which represents the disparity of currents and which, once amplified and processed by an electronic subsystem, provides a negative feedback which adjusts automatically the value of the comparison current which cancels said electromotive force thereby setting the equality between the known effective value of the comparison current and the effective value of the current to be measured, so that it is possible to calculate automatically the electric consumption and to transmit the results of said calculations via an interface in telematic applications.