Pickup Magnetic Sensors: a Dedicated Simulation Tool to Evaluate Innovative Hybrid Materials

Magnetic sensors are widely adopted in many industrial fields, particularly where the environmental conditions are difficult. A particular application, represented by a guitar pickup has been taken as reference to test innovative magnetic materials. The materials here proposed are Hybrid Magnetic Composites (HMC), obtained mixing together magnetic powder (Neodymium), a polymeric binder and a percentage of iron and then pressing in a mold. The resulting material presents a magnetic characteristic quite similar to those of AlNiCo, normally adopted in these kinds of pickup. In order to foresee the behavior of the sensor with a large number of possible materials, a dedicated simulation model has been realized; the simulation of the flux linkage in the coil, and the consequent induced voltage allows to compare the results and focus the attention on the most promising materials. AlNiCo, bonded magnets and HMC are compared in terms of performance. Contrarily to what can be imagined the materials with higher magnetic characteristics are not the best solution; particular attention has been in fact devoted to the evaluation of the attractive force between the magnets and the strings, that cannot be too high.