Side-looking speed sensor

摘要

An elongated generally cylindrical speed sensing device for sensing the speed of a toothed wheel to one side of the device, the device axis being transverse to the wheel axis and the device being generally tangential to the wheel. An elongated soft magnetic pole piece is surrounded by a coil coaxial with the pole piece, and a laterally extending circular symmetrical pole piece projection extends past an end of the coil to a diameter at least equal to the outside diameter of the coil. An axially magnetized permanent magnet abuts one end of the elongated pole piece. The device housing has rotationally symmetrical mounting surfaces coaxial with the magnetic axis so that angular alignment in installation is not required.