Abstract: A road wheel speed sensor for use with an automotive vehicle supported on road wheels. A pulsating variation in magnetic flux is produced with rotation of one of the road wheels. A signal converter is provided for converting the pulsation magnetic flux variation into a rectangular pulse signal to switching a transistor on and off. The signal converter is connected through power and signal lines to a processor. The transistor has a base electrode for receipt of the rectangular pulse signal, an emitter electrode, and a collector electrode connected to the signal line. A first resistor is connected between the power line and the signal line. A second resistor is connected between the power line and the emitter electrode of the transistor. A third resistor is connected between the signal line and the ground. The processor calculates a speed of rotation of the road wheel in response to a voltage developed across the third resistor.

Abstract: A pivotal armature on which a resilient elastomeric body is mounted, is arranged to be engageable with first and second surfaces in a manner which limits its movement and which holds the armature in a first closed valve position wherein the elastomeric body is permitted to engage and close a valve port but prevented from undergoing excessive deformation and a second valve open position wherein the elastomeric body is moved just sufficiently to open the port.