Encapsulated contactless magnetoresistive AC and DC current sensor - has plug-in IC incorporating split current path and permanent magnet stabiliser giving linear, externally adjustable response

摘要

The encapsulated (5) sensor for the contactless measurement of AC and DC current employs a substrate (3) carrying an IC and the paired input and output terminals (1,2). The current flow is divided into two discrete paths by suitable conductors one of which carries a magnetoresistive field detector (4) insulated from the conductor and the other is routed outside the encapsulation (5) for resistance/response adjustment. A permanent magnet (7) is situated between the conductors for reasons of magnetic alignment/stabilisation of the detector (4) and the IC is designed for balanced bridge operation via four of the output terminals (12) whilst the remaining two provide a signal proportional to input current. USE/ADVANTAGE - For power supplies or motor control. Has reproducible and stable parameters and is suitable for standardised high-volume, low-cost manufacture. Range and sensitivity can be set after manufacture by laser or mechanical trimming of external conductor. Design protects against polarity reversal by short-circuit currents.