Real-time broadband subnoise level signal extraction in Hall sensors

Abstract

This paper deals with the optimization of the "spinning-current" modulation method for cancelling the lowfrequency noise at the output of a Hall sensor. This method, based on Onsager reciprocity relationships through the reversemagnetic-field-reciprocity theorem of Sample et al., allows extracting magnetic field signals whose spectral intensity is much lower than the PSD of the low-frequency (LF) noise observed in the measurement: this includes the LF noise of the Hall sensor, the LF noise of the preamplifier, or the environmental noise due to electromagnetic interferences (EMI). Contrarily to methods based on the lock-in detection principle, which results in a narrow bandpass filtering, the LF-noise-free magnetic sensor signal remains broadband (DC to kHz). An improvement of 30dB in the S/N ratio can be observed around 1 Hz.

Modeling and design of single ring core DC sensor based on a new readout method for DC power system protection

“…Therefore, the variation of I results in the variation of tREF. The relationship between I and tREF can be described by Formula (11). presents two curves of uo, with each curve being associated with a different DC value.…”

“…The DC sensor may be classified based on electromagnetic induction and other technologies, such as micro-electro-mechanical systems [6]- [8] and opticfiber [9]- [10]. The DC sensor based on electromagnetic induction technology can also be subdivided into hall effect [11]- [12] and magnetic modulation [13]- [16]. 4Readout strategies.…”

Electronic Improvements made for Industrial Valve

“…Among some of the newer technologies, Hall Effect sensors use a moving permanent magnet to create induction (electric current), sensed by the device. This eliminates the contact problems of mechanical limit switches, but they are susceptible to high magnetic fields [5]- [7]. Optical sensors use a light emitter to generate light and a light receiver to detect the presence of an object without physical contact [8].…”