Wattmeter with AMR sensor

Analog multipliers comprising the Hall sensors have been used in electronic design, typically in powermeters. This article summarizes the results of experiments performed with a commercially available anisotropic magnetoresistive (AMR) sensor, used for the same purpose. The on-chip compensation coil can be successfully used in the function of the “current clamps” of the wattmeter. Periodical re-magnetizing (flipping) of the sensor structure performed by the flipping coil can improve the device parameters. This paper is not a description of a functioning, practice-ready device. It reports an experiment showing the feasibility of AMRs in the area of power measurements.