Reed switches have mechanical contacts, and so the contacts have a limited
lifespan, and they
are sensitive to impact and vibrations.
(Have you ever had reed switches that failed to work after product delivery? They may have been
affected by a strong impact during transportation or when mounting.)
AMR sensors have a higher impact durability than reed switches and a
smaller size.
When the magnet position cannot be changed significantly, the AMR sensor
can be turned off by
the direction of the magnetic force lines. This can be used for applications in switches with
extremely short strokes and in rotation detection.
Because the magnetic field detection direction is the same as reed
switches, magnets that were
used in reed switches may be able to be used without modification in AMR sensors in some cases.
The Simulation Tool can be used to conduct a general check of whether the sensor will operate
using the same magnet.
AMR Simulation Tool
In contrast to reed switches, AMR sensors include built-in switching
circuits, and a power
supply is required to operate the sensors. Be aware that AMR sensors may have different numbers
of wires and current consumptions.
For details, see Differences Between AMR Sensors (Magnetic Switches) and Other Systems.
Fundamentals of magnetic
sensors: differences between AMR sensors (magnetic switches) and reed switches