Sensors

Sensors are required almost everywhere. This may include measuring the fuel in your tank, monitoring the position of a shaft or measuring the speed of a device. Many of these measurements are made by producing a magnetic field using a magnet and then measuring flux produced by the magnet at one or more locations.

As most of these problems involve large amounts of free space, the boundary element method is ideally suited for these applications. Voltage calculations are simply derived by the software calculating the rate of change of flux within a coil. This, determining the size of magnets and coil or the desired amount of turns per coil to optimize the design, can be automated easily. Contour plots, graphs, isosurfaces and arrow plots enable the designer to see the “flow” of the magnetic field to optimize sensors locations.

Some specific sensor types:

Inductive/Eddy Current Sensors

MAGNETO (2D/RS) or AMPERES (3D Simulation) are normally sufficient unless the sensor components will develop eddy currents. If eddy current effects must be included, OERSTED (2D/RS) or FARADAY (3D Simulation) will be required.

Capacitive Sensors

ELECTRO (2D/RS) or COULOMB (3D Simulation) can be used to calculate the capacitance of the sensor based on model geometry and material properties.

Variable Reluctance Sensors

MAGNETO (2D/RS) or AMPERES (3D Simulation) can calculate flux linkages of pickup coils and thus predict sensor output.

LVDT Sensors

Usually OERSTED (2D/RS) or FARADAY (3D Simulation) will be required because of eddy currents induced in the sensor components. If the sensor is composed of ferrite and/or laminated materials, MAGNETO (2D/RS) or AMPERES (3D Simulation) should be sufficient.

Simulations using INTEGRATED's CAE software permit determination of equivalent circuit parameters and/or induced signals.

Analysis Type	2D or RS	3D
Electric Properties	ELECTRO	COULOMB
Magnetic Properties	MAGNETO	AMPERES
Eddy currents plus magnetic properties	OERSTED	FARADAY