Rotational speed sensor for high temperature

TLDR: In this paper, a series resonant circuit with a sensor coil is proposed for future wheel speed applications in trucks based on a series of resonant circuits with a diameter smaller than 15 mm, which can cover the whole rotational speed range beginning at standstill but also the temperature range up to more than 200°C.

Abstract: A new sensor concept for future wheel speed applications in trucks based on a series resonant circuit with a sensor coil is proposed. This sensor is not only able to cover the whole rotational speed range beginning at standstill but also the temperature range up to more than 200°C. In addition a digital current interface, self-diagnosis-capability and additional information about airgap and temperature can be provided in order to enhance the reliability of the system. With this sensor concept it is possible to replace the currently used inductive sensors with rotational symmetry (TIM: Twist Insensitive Mounting) and a diameter smaller than about 15 mm. Additional electronics and signal processing are required to provide all capabilities mentioned above.