Littelfuse Pulsed WaveGuide™ (PWG™) sensor technology, patent pending1, is a cost effective linear position sensing technology that is capable of producing a highly versatile, robust and accurate distance measurement solution.
The Pulsed WaveGuide Sensor package contains signal conditioning electronics and a screened wave guide transmission line - the sensing element. When used in conjunction with a suitable permanent magnet, the signal transmitted along the wave guide is reflected at the magnet position. The time of flight between the start of transmission and the reflected signal is directly proportional to the distance between the starting point of the wave guide and the magnet position.
In order to minimize power consumption, the measurement frequency can be optimized. In addition, the measurement mode can also be set to burst mode and poll mode. In burst mode the system enters a sleep state and awakes to report position at preset intervals; in poll mode the sensor reports position upon demand from an ECU.