Noncontact rotary sensors for automotive use

As automotive systems develop in their complexity and performance a need has emerged for noncontact rotary position sensors which offer significant durability enhancements over traditional resistive track rotary devices. Such reliability improvements are particularly important when the sensor is to be used with safety critical chassis and power-train management systems. Contactless rotary sensors can be devised using variable inductance planar coils, these being etched onto standard printed circuit boards. Such sensors can then be driven and decoded using custom oscillator and switching circuitry, conveniently integrated into a single ASIC chip. Various configurations of sensor are described, together with some of the design techniques used to devise sensors which meet the automotive industry requirements for quality, durability and manufacturability. Typical performance results will also be illustrated in representative automotive applications.<
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